javadoc(1) Basic Tools javadoc(1)
NAME
javadoc - Generates HTML pages of API documentation from Java source
files.
SYNOPSIS
javadoc {packages|source-files} [options] [@argfiles]
packages
Names of packages that you want to document, separated by
spaces, for example java.lang java.lang.reflect java.awt. If you
want to also document the subpackages, use the -subpackages
option to specify the packages.
By default, javadoc looks for the specified packages in the
current directory and subdirectories. Use the -sourcepath option
to specify the list of directories where to look for packages.
source-files
Names of Java source files that you want to document, separated
by spaces, for example Class.java Object.java Button.java. By
default, javadoc looks for the specified classes in the current
directory. However, you can specify the full path to the class
file and use wildcard characters, for example
/home/src/java/awt/Graphics*.java. You can also specify the path
relative to the current directory.
options
Command-line options, separated by spaces. See Options.
@argfiles
Names of files that contain a list of javadoc command options,
package names and source file names in any order.
DESCRIPTION
The javadoc command parses the declarations and documentation comments
in a set of Java source files and produces a corresponding set of HTML
pages that describe (by default) the public and protected classes,
nested classes (but not anonymous inner classes), interfaces,
constructors, methods, and fields. You can use the javadoc command to
generate the API documentation or the implementation documentation for
a set of source files.
You can run the javadoc command on entire packages, individual source
files, or both. When documenting entire packages, you can either use
the -subpackages option to recursively traverse a directory and its
subdirectories, or to pass in an explicit list of package names. When
you document individual source files, pass in a list of Java source
file names. See Simple Examples.
PROCESS SOURCE FILES
The javadoc command processes files that end in source and other files
described in Source Files. If you run the javadoc command by passing in
individual source file names, then you can determine exactly which
source files are processed. However, that is not how most developers
want to work, because it is simpler to pass in package names. The
javadoc command can be run three ways without explicitly specifying the
source file names. You can pass in package names, use the -subpackages
option, or use wild cards with source file names. In these cases, the
javadoc command processes a source file only when the file fulfills all
of the following requirements:
o The file name prefix (with .java removed) is a valid class name.
o The path name relative to the root of the source tree is a valid
package name after the separators are converted to dots.
o The package statement contains the valid package name.
Processing Links
During a run, the javadoc command adds cross-reference links to
package, class, and member names that are being documented as part of
that run. Links appear in the following places. See Javadoc Tags for a
description of the @ tags.
o Declarations (return types, argument types, and field types).
o See Also sections that are generated from @see tags.
o Inline text generated from {@link} tags.
o Exception names generated from @throws tags.
o Specified by links to interface members and Overrides links to class
members. See Method Comment Inheritance.
o Summary tables listing packages, classes and members.
o Package and class inheritance trees.
o The index.
You can add links to existing text for classes not included on the
command line (but generated separately) by way of the -link and
-linkoffline options.
Processing Details
The javadoc command produces one complete document every time it runs.
It does not do incremental builds that modify or directly incorporate
the results from earlier runs. However, the javadoc command can link to
results from other runs.
The javadoc command implementation requires and relies on the Java
compiler. The javadoc command calls part of the javac command to
compile the declarations and ignore the member implementations. The
javadoc command builds a rich internal representation of the classes
that includes the class hierarchy and use relationships to generate the
HTML. The javadoc command also picks up user-supplied documentation
from documentation comments in the source code. See Documentation
Comments.
The javadoc command runs on source files that are pure stub files with
no method bodies. This means you can write documentation comments and
run the javadoc command in the early stages of design before API
implementation.
Relying on the compiler ensures that the HTML output corresponds
exactly with the actual implementation, which may rely on implicit,
rather than explicit, source code. For example, the javadoc command
documents default constructors that are present in the compiled class
files but not in the source code.
In many cases, the javadoc command lets you generate documentation for
source files with incomplete or erroneous code. You can generate
documentation before all debugging and troubleshooting is done. The
javadoc command does primitive checking of documentation comments.
When the javadoc command builds its internal structure for the
documentation, it loads all referenced classes. Because of this, the
javadoc command must be able to find all referenced classes, whether
bootstrap classes, extensions, or user classes. See How Classes Are
Found at
http://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html
Typically, classes you create must either be loaded as an extension or
in the javadoc command class path.
JAVADOC DOCLETS
You can customize the content and format of the javadoc command output
with doclets. The javadoc command has a default built-in doclet, called
the standard doclet, that generates HTML-formatted API documentation.
You can modify or make a subclass of the standard doclet, or write your
own doclet to generate HTML, XML, MIF, RTF or whatever output format
you want.
When a custom doclet is not specified with the -doclet option, the
javadoc command uses the default standard doclet. The javadoc command
has several options that are available regardless of which doclet is
being used. The standard doclet adds a supplementary set of command-
line options. See Options.
SOURCE FILES
The javadoc command generates output that originates from the following
types of source files: Java language source files for classes (.java),
package comment files, overview comment files, and miscellaneous
unprocessed files. This section also describes test files and template
files that can also be in the source tree, but that you want to be sure
not to document.
CLASS SOURCE FILES
Each class or interface and its members can have their own
documentation comments contained in a source file. See Documentation
Comments.
PACKAGE COMMENT FILES
Each package can have its own documentation comment, contained in its
own source file, that the javadoc command merges into the generated
package summary page. You typically include in this comment any
documentation that applies to the entire package.
To create a package comment file, you can place your comments in one of
the following files:
o The package-info.java file can contain the package declaration,
package annotations, package comments, and Javadoc tags. This file is
preferred.
o The package.html file contains only package comments and Javadoc
tags. No package annotations.
A package can have a single package.html file or a single package-
info.java file, but not both. Place either file in the package
directory in the source tree with your source files.
The package-info.java File
The package-info.java file can contain a package comment of the
following structure. The comment is placed before the package
declaration.
Note: The comment separators /** and */ must be present, but the
leading asterisks on the intermediate lines can be left off.
/**
* Provides the classes necessary to create an
* applet and the classes an applet uses
* to communicate with its applet context.
*
* The applet framework involves two entities:
* the applet and the applet context.
* An applet is an embeddable window (see the
* {@link java.awt.Panel} class) with a few extra
* methods that the applet context can use to
* initialize, start, and stop the applet.
*
* @since 1.0
* @see java.awt
*/
package java.lang.applet;
The package.html File
The package.html file can contain a package comment of the following
structure. The comment is placed in the
element.
File: java/applet/package.html
Provides the classes necessary to create an applet and the
classes an applet uses to communicate with its applet context.
The applet framework involves two entities: the applet
and the applet context. An applet is an embeddable
window (see the {@link java.awt.Panel} class) with a
few extra methods that the applet context can use to
initialize, start, and stop the applet.
@since 1.0
@see java.awt
The package.html file is a typical HTML file and does not include a
package declaration. The content of the package comment file is written
in HTML with one exception. The documentation comment should not
include the comment separators /** and */ or leading asterisks. When
writing the comment, make the first sentence a summary about the
package, and do not put a title or any other text between the
tag and the first sentence. You can include package tags. All block
tags must appear after the main description. If you add an @see tag in
a package comment file, then it must have a fully qualified name.
Processing the Comment File
When the javadoc command runs, it searches for the package comment
file. If the package comment file is found, then the javadoc command
does the following:
o Copies the comment for processing. For package.html, the javadoc
command copies all content between the and HTML tags.
You can include a section to put a tag, source file
copyright statement, or other information, but none of these appear
in the generated documentation.
o Processes the package tags. See Package Tags.
o Inserts the processed text at the bottom of the generated package
summary page. See Java Platform, Standard Edition API Specification
Overview at http://docs.oracle.com/javase/8/docs/api/overview-
summary.html
o Copies the first sentence of the package comment to the top of the
package summary page. The javadoc command also adds the package name
and this first sentence to the list of packages on the overview page.
See Java Platform, Standard Edition API Specification Overview at
http://docs.oracle.com/javase/8/docs/api/overview-summary.html
The end of the sentence is determined by the same rules used for the
end of the first sentence of class and member main descriptions.
OVERVIEW COMMENT FILES
Each application or set of packages that you are documenting can have
its own overview documentation comment that is kept in its own source
file, that the javadoc command merges into the generated overview page.
You typically include in this comment any documentation that applies to
the entire application or set of packages.
You can name the file anything you want such as overview.html and place
it anywhere. A typical location is at the top of the source tree.
For example, if the source files for the java.applet package are
contained in the /home/user/src/java/applet directory, then you could
create an overview comment file at /home/user/src/overview.html.
You can have multiple overview comment files for the same set of source
files in case you want to run the javadoc command multiple times on
different sets of packages. For example, you could run the javadoc
command once with -private for internal documentation and again without
that option for public documentation. In this case, you could describe
the documentation as public or internal in the first sentence of each
overview comment file.
The content of the overview comment file is one big documentation
comment that is written in HTML. Make the first sentence a summary
about the application or set of packages. Do not put a title or any
other text between the <body> tag and the first sentence. All tags
except inline tags, such as an {@link} tag, must appear after the main
description. If you add an @see tag, then it must have a fully
qualified name.
When you run the javadoc command, specify the overview comment file
name with the -overview option. The file is then processed similarly to
that of a package comment file. The javadoc command does the following:
o Copies all content between the <body> and </body> tags for
processing.
o Processes the overview tags that are present. See Overview Tags.
o Inserts the processed text at the bottom of the generated overview
page. See Java Platform Standard Edition API Specification Overview
at http://docs.oracle.com/javase/8/docs/api/overview-summary.html
o Copies the first sentence of the overview comment to the top of the
overview summary page.
UNPROCESSED FILES
Your source files can include any files that you want the javadoc
command to copy to the destination directory. These files usually
include graphic files, example Java source and class files, and self-
standing HTML files with a lot of content that would overwhelm the
documentation comment of a typical Java source file.
To include unprocessed files, put them in a directory called doc-files.
The doc-files directory can be a subdirectory of any package directory
that contains source files. You can have one doc-files subdirectory for
each package.
For example, if you want to include the image of a button in the
java.awt.Button class documentation, then place the image file in the
/home/user/src/java/awt/doc-files/ directory. Do not place the doc-
files directory at /home/user/src/java/doc-files, because java is not a
package. It does not contain any source files.
All links to the unprocessed files must be included in the code because
the javadoc command does not look at the files. The javadoc command
copies the directory and all of its contents to the destination. The
following example shows how the link in the Button.java documentation
comment might look:
/**
* This button looks like this:
* <img src="doc-files/Button.gif">
*/
TEST AND TEMPLATE FILES
You can store test and template files in the source tree in the same
directory with or in a subdirectory of the directory where the source
files reside. To prevent test and template files from being processed,
run the javadoc command and explicitly pass in individual source file
names.
Test files are valid, compilable source files. Template files are not
valid, compatible source files, but they often have the .java suffix.
Test Files
If you want your test files to belong to either an unnamed package or
to a package other than the package that the source files are in, then
put the test files in a subdirectory underneath the source files and
give the directory an invalid name. If you put the test files in the
same directory with the source and call the javadoc command with a
command-line argument that indicates its package name, then the test
files cause warnings or errors. If the files are in a subdirectory with
an invalid name, then the test file directory is skipped and no errors
or warnings are issued. For example, to add test files for source files
in com.package1, put them in a subdirectory in an invalid package name.
The following directory name is invalid because it contains a hyphen:
com/package1/test-files/
If your test files contain documentation comments, then you can set up
a separate run of the javadoc command to produce test file
documentation by passing in their test source file names with wild
cards, such as com/package1/test-files/*.java.
Template Files
If you want a template file to be in the source directory, but not
generate errors when you execute the javadoc command, then give it an
invalid file name such as Buffer-Template.java to prevent it from being
processed. The javadoc command only processes source files with names,
when stripped of the .java suffix, that are valid class names.
GENERATED FILES
By default, the javadoc command uses a standard doclet that generates
HTML-formatted documentation. The standard doclet generates basic
content, cross-reference, and support pages described here. Each HTML
page corresponds to a separate file. The javadoc command generates two
types of files. The first type is named after classes and interfaces.
The second type contain hyphens (such as package-summary.html) to
prevent conflicts with the first type of file.
BASIC CONTENT PAGES
o One class or interface page (classname.html) for each class or
interface being documented.
o One package page (package-summary.html) for each package being
documented. The javadoc command includes any HTML text provided in a
file with the name package.html or package-info.java in the package
directory of the source tree.
o One overview page (overview-summary.html) for the entire set of
packages. The overview page is the front page of the generated
document. The javadoc command includes any HTML text provided in a
file specified by the -overview option. The Overview page is created
only when you pass two or more package names into the javadoc
command. See HTML Frames and Options.
CROSS-REFERENCE PAGES
o One class hierarchy page for the entire set of packages (overview-
tree.html). To view the hierarchy page, click Overview in the
navigation bar and click Tree.
o One class hierarchy page for each package (package-tree.html) To view
the hierarchy page, go to a particular package, class, or interface
page, and click Tree to display the hierarchy for that package.
o One use page for each package (package-use.html) and a separate use
page for each class and interface (class-use/classname.html). The use
page describes what packages, classes, methods, constructors and
fields use any part of the specified class, interface, or package.
For example, given a class or interface A, its use page includes
subclasses of A, fields declared as A, methods that return A, and
methods and constructors with parameters of type A. To view the use
page, go to the package, class, or interface and click the Use link
in the navigation bar.
o A deprecated API page (deprecated-list.html) that lists all
deprecated APIs and their suggested replacements. Avoid deprecated
APIs because they can be removed in future implementations.
o A constant field values page (constant-values.html) for the values of
static fields.
o A serialized form page (serialized-form.html) that provides
information about serializable and externalizable classes with field
and method descriptions. The information on this page is of interest
to reimplementors, and not to developers who want to use the API. To
access the serialized form page, go to any serialized class and click
Serialized Form in the See Also section of the class comment. The
standard doclet generates a serialized form page that lists any class
(public or non-public) that implements Serializable with its
readObject and writeObject methods, the fields that are serialized,
and the documentation comments from the @serial, @serialField, and
@serialData tags. Public serializable classes can be excluded by
marking them (or their package) with @serial exclude, and package-
private serializable classes can be included by marking them (or
their package) with an @serial include. As of Release 1.4, you can
generate the complete serialized form for public and private classes
by running the javadoc command without specifying the -private
option. See Options.
o An index page (index-*.html) of all class, interface, constructor,
field and method names, in alphabetical order. The index page is
internationalized for Unicode and can be generated as a single file
or as a separate file for each starting character (such as A-Z for
English).
SUPPORT PAGES
o A help page (help-doc.html) that describes the navigation bar and the
previous pages. Use -helpfile to override the default help file with
your own custom help file.
o One index.html file that creates the HTML frames for display. Load
this file to display the front page with frames. The index.html file
contains no text content.
o Several frame files (*-frame.html) that contains lists of packages,
classes, and interfaces. The frame files display the HTML frames.
o A package list file (package-list) that is used by the -link and
-linkoffline options. The package list file is a text file that is
not reachable through links.
o A style sheet file (stylesheet.css) that controls a limited amount of
color, font family, font size, font style, and positioning
information on the generated pages.
o A doc-files directory that holds image, example, source code, or
other files that you want copied to the destination directory. These
files are not processed by the javadoc command. This directory is not
processed unless it exists in the source tree.
See Options.
HTML FRAMES
The javadoc command generates the minimum number of frames (two or
three) necessary based on the values passed to the command. It omits
the list of packages when you pass a single package name or source
files that belong to a single package as an argument to the javadoc
command. Instead, the javadoc command creates one frame in the left-
hand column that displays the list of classes. When you pass two or
more package names, the javadoc command creates a third frame that
lists all packages and an overview page (overview-summary.html). To
bypass frames, click the No Frames link or enter the page set from the
overview-summary.html page.
GENERATED FILE STRUCTURE
The generated class and interface files are organized in the same
directory hierarchy that Java source files and class files are
organized. This structure is one directory per subpackage.
For example, the document generated for the java.applet.Applet class
would be located at java/applet/Applet.html.
The file structure for the java.applet package follows, assuming that
the destination directory is named apidocs. All files that contain the
word frame appear in the upper-left or lower-left frames, as noted. All
other HTML files appear in the right-hand frame.
Directories are bold. The asterisks (*) indicate the files and
directories that are omitted when the arguments to the javadoc command
are source file names rather than package names. When arguments are
source file names, an empty package list is created. The doc-files
directory is not created in the destination unless it exists in the
source tree. See Generated Files.
o apidocs: Top-level directory
o index.html: Initial Page that sets up HTML frames
o *overview-summary.html: Package list with summaries
o overview-tree.html: Class hierarchy for all packages
o deprecated-list.html: Deprecated APIs for all packages
o constant-values.html: Static field values for all packages
o serialized-form.html: Serialized forms for all packages
o *overview-frame.html: All packages for display in upper-left frame
o allclasses-frame.html: All classes for display in lower-left frame
o help-doc.html: Help about Javadoc page organization
o index-all.html: Default index created without -splitindex option
o index-files: Directory created with -splitindex option
o index-<number>.html: Index files created with -splitindex option
o package-list: Package names for resolving external references
o stylesheet.css: Defines fonts, colors, positions, and so on
o java: Package directory
o applet: Subpackage directory
o Applet.html: Applet class page
o AppletContext.html: AppletContext interface
o AppletStub.html: AppletStub interface
o AudioClip.html: AudioClip interface
o package-summary.html: Classes with summaries
o package-frame.html: Package classes for display in lower-left
frame
o package-tree.html: Class hierarchy for this package
o package-use.html: Where this package is used
o doc-files: Image and example files directory
o class-use: Image and examples file location
- Applet.html: Uses of the Applet class
- AppletContext.html: Uses of the AppletContext interface
- AppletStub.html: Uses of the AppletStub interface
- AudioClip.html: Uses of the AudioClip interface
o src-html: Source code directory
o java: Package directory
o applet: Subpackage directory
- Applet.html: Applet source code
- AppletContext.html: AppletContext source code
- AppletStub.html: AppletStub source code
- AudioClip.html: AudioClip source code
GENERATED API DECLARATIONS
The javadoc command generates a declaration at the start of each class,
interface, field, constructor, and method description for that API
item. For example, the declaration for the Boolean class is:
public final class Boolean
extends Object
implements Serializable
The declaration for the Boolean.valueOf method is:
public static Boolean valueOf(String s)
The javadoc command can include the modifiers public, protected,
private, abstract, final, static, transient, and volatile, but not
synchronized or native. The synchronized and native modifiers are
considered implementation detail and not part of the API specification.
Rather than relying on the keyword synchronized, APIs should document
their concurrency semantics in the main description of the comment. For
example, a description might be: A single enumeration cannot be used by
multiple threads concurrently. The document should not describe how to
achieve these semantics. As another example, while the Hashtable option
should be thread-safe, there is no reason to specify that it is
achieved by synchronizing all of its exported methods. It is better to
reserve the right to synchronize internally at the bucket level for
higher concurrency.
DOCUMENTATION COMMENTS
This section describes source code comments and comment inheritance.
SOURCE CODE COMMENTS
You can include documentation comments in the source code, ahead of
declarations for any class, interface, method, constructor, or field.
You can also create documentation comments for each package and another
one for the overview, though their syntax is slightly different. A
documentation comment consists of the characters between /** and */
that end it. Leading asterisks are allowed on each line and are
described further in the following section. The text in a comment can
continue onto multiple lines.
/**
* This is the typical format of a simple documentation comment
* that spans two lines.
*/
To save space you can put a comment on one line:
/** This comment takes up only one line. */
Placement of Comments
Documentation comments are recognized only when placed immediately
before class, interface, constructor, method, or field declarations.
Documentation comments placed in the body of a method are ignored. The
javadoc command recognizes only one documentation comment per
declaration statement. See Where Tags Can Be Used.
A common mistake is to put an import statement between the class
comment and the class declaration. Do not put an import statement at
this location because the javadoc command ignores the class comment.
/**
* This is the class comment for the class Whatever.
*/
import com.example; // MISTAKE - Important not to put import statement here
public class Whatever{ }
Parts of Comments
A documentation comment has a main description followed by a tag
section. The main description begins after the starting delimiter /**
and continues until the tag section. The tag section starts with the
first block tag, which is defined by the first @ character that begins
a line (ignoring leading asterisks, white space, and leading separator
/**). It is possible to have a comment with only a tag section and no
main description. The main description cannot continue after the tag
section begins. The argument to a tag can span multiple lines. There
can be any number of tags, and some types of tags can be repeated while
others cannot. For example, this @see tag starts the tag section:
/**
* This sentence holds the main description for this documentation comment.
* @see java.lang.Object
*/
Block and inline Tags
A tag is a special keyword within a documentation comment that the
javadoc command processes. There are two kinds of tags: block tags,
which appear as an @tag tag (also known as standalone tags), and inline
tags, which appear within braces, as an {@tag} tag. To be interpreted,
a block tag must appear at the beginning of a line, ignoring leading
asterisks, white space, and the separator (/**). This means you can use
the @ character elsewhere in the text and it will not be interpreted as
the start of a tag. If you want to start a line with the @ character
and not have it be interpreted, then use the HTML entity @. Each
block tag has associated text, which includes any text following the
tag up to, but not including, either the next tag, or the end of the
documentation comment. This associated text can span multiple lines. An
inline tag is allowed and interpreted anywhere that text is allowed.
The following example contains the @deprecated block tag and the
{@link} inline tag. See Javadoc Tags.
/**
* @deprecated As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}
*/
Write Comments in HTML
The text must be written in HTML with HTML entities and HTML tags. You
can use whichever version of HTML your browser supports. The standard
doclet generates HTML 3.2-compliant code elsewhere (outside of the
documentation comments) with the inclusion of cascading style sheets
and frames. HTML 4.0 is preferred for generated files because of the
frame sets.
For example, entities for the less than symbol (<) and the greater than
symbol (>) should be written as < and >. Similarly, the ampersand
(&) should be written as &. The bold HTML tag <b> is shown in the
following example.
/**
* This is a <b>doc</b> comment.
* @see java.lang.Object
*/
Leading Asterisks
When the javadoc command parses a documentation comment, leading
asterisks (*) on each line are discarded, and blanks and tabs that
precede the initial asterisks (*) are also discarded. If you omit the
leading asterisk on a line, then the leading white space is no longer
removed so that you can paste code examples directly into a
documentation comment inside a <PRE> tag with its indentation
preserved. Spaces are interpreted by browsers more uniformly than tabs.
Indentation is relative to the left margin (rather than the separator
/** or <PRE> tag).
First Sentence
The first sentence of each documentation comment should be a summary
sentence that contains a concise but complete description of the
declared entity. This sentence ends at the first period that is
followed by a blank, tab, or line terminator, or at the first block
tag. The javadoc command copies this first sentence to the member
summary at the top of the HTML page.
Multiple-Field Declarations
The Java platform lets you declare multiple fields in a single
statement, but this statement can have only one documentation comment
that is copied for all fields. If you want individual documentation
comments for each field, then declare each field in a separate
statement. For example, the following documentation comment does not
make sense written as a single declaration and would be better handled
as two declarations:
/**
* The horizontal and vertical distances of point (x,y)
*/
public int x, y; // Avoid this
The javadoc command generates the following documentation from the
previous code:
public int x
The horizontal and vertical distances of point (x, y).
public int y
The horizontal and vertical distances of point (x, y).
Use of Header Tags
When writing documentation comments for members, it is best not to use
HTML heading tags such as <H1> and <H2>, because the javadoc command
creates an entire structured document, and these structural tags might
interfere with the formatting of the generated document. However, you
can use these headings in class and package comments to provide your
own structure.
METHOD COMMENT INHERITANCE
The javadoc command allows method comment inheritance in classes and
interfaces to fill in missing text or to explicitly inherit method
comments. Constructors, fields, and nested classes do not inherit
documentation comments.
Note: The source file for an inherited method must be on the path
specified by the -sourcepath option for the documentation comment to be
available to copy. Neither the class nor its package needs to be passed
in on the command line. This contrasts with Release 1.3.n and earlier
releases, where the class had to be a documented class.
Fill in Missing Text
When a main description, or @return, @param, or @throws tag is missing
from a method comment, the javadoc command copies the corresponding
main description or tag comment from the method it overrides or
implements (if any). See Method Comment Inheritance.
When an @param tag for a particular parameter is missing, the comment
for that parameter is copied from the method further up the inheritance
hierarchy. When an @throws tag for a particular exception is missing,
the @throws tag is copied only when that exception is declared.
This behavior contrasts with Release 1.3 and earlier, where the
presence of any main description or tag would prevent all comments from
being inherited.
See Javadoc Tags and Options.
Explicit Inheritance
Insert the {@inheritDoc} inline tag in a method main description or
@return, @param, or @throws tag comment. The corresponding inherited
main description or tag comment is copied into that spot.
CLASS AND INTERFACE INHERITANCE
Comment inheritance occurs in all possible cases of inheritance from
classes and interfaces:
o When a method in a class overrides a method in a superclass
o When a method in an interface overrides a method in a superinterface
o When a method in a class implements a method in an interface
In the first two cases, the javadoc command generates the subheading
Overrides in the documentation for the overriding method. A link to the
method being overridden is included, whether or not the comment is
inherited.
In the third case, when a method in a specified class implements a
method in an interface, the javadoc command generates the subheading
Specified by in the documentation for the overriding method. A link to
the method being implemented is included, whether or not the comment is
inherited.
METHOD COMMENTS ALGORITHM
If a method does not have a documentation comment, or has an
{@inheritDoc} tag, then the javadoc command uses the following
algorithm to search for an applicable comment. The algorithm is
designed to find the most specific applicable documentation comment,
and to give preference to interfaces over superclasses:
1. Look in each directly implemented (or extended) interface in the
order they appear following the word implements (or extends) in the
method declaration. Use the first documentation comment found for
this method.
2. If Step 1 failed to find a documentation comment, then recursively
apply this entire algorithm to each directly implemented (or
extended) interface in the same order they were examined in Step 1.
3. When Step 2 fails to find a documentation comment and this is a
class other than the Object class, but not an interface:
1. If the superclass has a documentation comment for this method,
then use it.
2. If Step 3a failed to find a documentation comment, then
recursively apply this entire algorithm to the superclass.
JAVADOC TAGS
The javadoc command parses special tags when they are embedded within a
Java documentation comment. The javadoc tags let you autogenerate a
complete, well-formatted API from your source code. The tags start with
an at sign (@) and are case-sensitive. They must be typed with the
uppercase and lowercase letters as shown. A tag must start at the
beginning of a line (after any leading spaces and an optional
asterisk), or it is treated as text. By convention, tags with the same
name are grouped together. For example, put all @see tags together. For
more information, see Where Tags Can Be Used.
Tags have the following types:
o Bock tags: Place block tags only in the tag section that follows the
description. Block tags have the form: @tag.
o Inline tags: Place inline tags anywhere in the main description or in
the comments for block tags. Inline tags are enclosed within braces:
{@tag}.
For custom tags, see -tag tagname:Xaoptcmf:"taghead". See also Where
Tags Can Be Used.
TAG DESCRIPTIONS
@author name-text
Introduced in JDK 1.0
Adds an Author entry with the specified name text to the
generated documents when the -author option is used. A
documentation comment can contain multiple @author tags. You can
specify one name per @author tag or multiple names per tag. In
the former case, the javadoc command inserts a comma (,) and
space between names. In the latter case, the entire text is
copied to the generated document without being parsed.
Therefore, you can use multiple names per line if you want a
localized name separator other than a comma. See @author in How
to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@author
{@code text}
Introduced in JDK 1.5
Equivalent to <code>{@literal}</code>.
Displays text in code font without interpreting the text as HTML
markup or nested Javadoc tags. This enables you to use regular
angle brackets (< and >) instead of the HTML entities (< and
>) in documentation comments, such as in parameter types
(<Object>), inequalities (3 < 4), or arrows (<-). For example,
the documentation comment text {@code A<B>C} displayed in the
generated HTML page unchanged as A<B>C. This means that the <B>
is not interpreted as bold and is in code font. If you want the
same functionality without the code font, then use the
{@literal} tag.
@deprecated deprecated-text
Introduced in JDK 1.0
Adds a comment indicating that this API should no longer be used
(even though it may continue to work). The javadoc command moves
deprecated-textahead of the main description, placing it in
italics and preceding it with a bold warning: Deprecated. This
tag is valid in all documentation comments: overview, package,
class, interface, constructor, method and field.
The first sentence of deprecated text should tell the user when
the API was deprecated and what to use as a replacement. The
javadoc command copies the first sentence to the summary section
and index. Subsequent sentences can also explain why it was
deprecated. You should include an {@link} tag (for Javadoc 1.2
or later) that points to the replacement API.
Use the @deprecated annotation tag to deprecate a program
element. See How and When to Deprecate APIs at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/deprecation/deprecation.html
See also @deprecated in How to Write Doc Comments for the
Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@deprecated
{@docRoot}
Introduced in JDK 1.3
Represents the relative path to the generated document's
(destination) root directory from any generated page. This tag
is useful when you want to include a file, such as a copyright
page or company logo, that you want to reference from all
generated pages. Linking to the copyright page from the bottom
of each page is common.
This {@docRoot} tag can be used both on the command line and in
a documentation comment. This tag is valid in all documentation
comments: overview, package, class, interface, constructor,
method and field, and includes the text portion of any tag (such
as the @return, @param and @deprecated tags).
o On the command line, where the header, footer, or bottom are
defined: javadoc -bottom '<a
href="{@docRoot}/copyright.html">Copyright</a>'.
When you use the {@docRoot} tag this way in a make file, some
makefile programs require a special way to escape for the
brace {} characters. For example, the Inprise MAKE version 5.2
running on Windows requires double braces: {{@docRoot}}. It
also requires double (rather than single) quotation marks to
enclose arguments to options such as the -bottom option (with
the quotation marks around the href argument omitted).
o In a documentation comment:
/**
* See the <a href="{@docRoot}/copyright.html">Copyright</a>.
*/
This tag is needed because the generated documents are in
hierarchical directories, as deep as the number of
subpackages. The expression: <a
href="{@docRoot}/copyright.html"> resolves to <a
href="../../copyright.html"> for java/lang/Object.java and <a
href="../../../copyright.html"> for
java/lang/ref/Reference.java.
@exception class-name description
Introduced in JDK 1.0
Identical to the @throws tag. See @throws class-name
description.
{@inheritDoc}
Introduced in JDK 1.4
Inherits (copies) documentation from the nearest inheritable
class or implementable interface into the current documentation
comment at this tag's location. This enables you to write more
general comments higher up the inheritance tree and to write
around the copied text.
This tag is valid only in these places in a documentation
comment:
o In the main description block of a method. In this case, the
main description is copied from a class or interface up the
hierarchy.
o In the text arguments of the @return, @param, and @throws tags
of a method. In this case, the tag text is copied from the
corresponding tag up the hierarchy.
See Method Comment Inheritance for a description of how comments are
found in the inheritance hierarchy. Note that if this tag is missing,
then the comment is or is not automatically inherited according to
rules described in that section.
{@link package.class#member label}
Introduced in JDK 1.2
Inserts an inline link with a visible text label that points to
the documentation for the specified package, class, or member
name of a referenced class. This tag is valid in all
documentation comments: overview, package, class, interface,
constructor, method and field, including the text portion of any
tag, such as the @return, @param and @deprecated tags. See @link
in How to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#{@link
This tag is similar to the @see tag. Both tags require the same
references and accept the same syntax for package.class#member
and label. The main difference is that the {@link} tag generates
an inline link rather than placing the link in the See Also
section. The {@link} tag begins and ends with braces to separate
it from the rest of the inline text. If you need to use the
right brace (}) inside the label, then use the HTML entity
notation }.
There is no limit to the number of {@link} tags allowed in a
sentence. You can use this tag in the main description part of
any documentation comment or in the text portion of any tag,
such as the @deprecated, @return or @param tags.
For example, here is a comment that refers to the
getComponentAt(int, int) method:
Use the {@link #getComponentAt(int, int) getComponentAt} method.
From this code, the standard doclet generates the following HTML
(assuming it refers to another class in the same package):
Use the <a href="Component.html#getComponentAt(int, int)">getComponentAt</a> method.
The previous line appears on the web page as:
Use the getComponentAt method.
{@linkplain package.class#member label}
Introduced in JDK 1.4
Behaves the same as the {@link} tag, except the link label is
displayed in plain text rather than code font. Useful when the
label is plain text. For example, Refer to {@linkplain add() the
overridden method}. displays as: Refer to the overridden method.
{@literal text}
Introduced in JDK 1.5
Displays text without interpreting the text as HTML markup or
nested Javadoc tags. This enables you to use angle brackets (<
and >) instead of the HTML entities (< and >) in
documentation comments, such as in parameter types (<Object>),
inequalities (3 < 4), or arrows (<-). For example, the
documentation comment text {@literal A<B>C} displays unchanged
in the generated HTML page in your browser, as A<B>C. The <B> is
not interpreted as bold (and it is not in code font). If you
want the same functionality with the text in code font, then use
the {@code} tag.
@param parameter-name description
Introduced in JDK 1.0
Adds a parameter with the specified parameter-name followed by
the specified description to the Parameters section. When
writing the documentation comment, you can continue the
description onto multiple lines. This tag is valid only in a
documentation comment for a method, constructor, or class. See
@param in How to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@param
The parameter-name can be the name of a parameter in a method or
constructor, or the name of a type parameter of a class, method,
or constructor. Use angle brackets around this parameter name to
specify the use of a type parameter.
Example of a type parameter of a class:
/**
* @param <E> Type of element stored in a list
*/
public interface List<E> extends Collection<E> {
}
Example of a type parameter of a method:
/**
* @param string the string to be converted
* @param type the type to convert the string to
* @param <T> the type of the element
* @param <V> the value of the element
*/
<T, V extends T> V convert(String string, Class<T> type) {
}
@return description
Introduced in JDK 1.0
Adds a Returns section with the description text. This text
should describe the return type and permissible range of values.
This tag is valid only in a documentation comment for a method.
See @return in How to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@return
@see reference
Introduced in JDK 1.0
Adds a See Also heading with a link or text entry that points to
a reference. A documentation comment can contain any number of
@see tags, which are all grouped under the same heading. The
@see tag has three variations. The form is the most common. This
tag is valid in any documentation comment: overview, package,
class, interface, constructor, method, or field. For inserting
an inline link within a sentence to a package, class, or member,
see {@link}.
Form 1. The @see string tag form adds a text entry for string.
No link is generated. The string is a book or other reference to
information not available by URL. The javadoc command
distinguishes this from the previous cases by searching for a
double quotation mark (") as the first character. For example,
@see "The Java Programming Language" that generates the
following text:
See Also:
"The Java Programming Language"
Form 2. The @see <a href="URL#value">label</a> form adds a link
as defined by URL#value. The URL#value parameter is a relative
or absolute URL. The javadoc command distinguishes this from
other cases by searching for a less-than symbol (<) as the first
character. For example, @see <a href="spec.html#section">Java
Spec</a> generates the following link:
See Also:
Java Spec
Form 3. The @see package.class#member label form adds a link
with a visible text label that points to the documentation for
the specified name in the Java Language that is referenced. The
label is optional. If the label is omitted, then the name
appears instead as visible text, suitably shortened. Use the
-noqualifier option to globally remove the package name from
this visible text. Use the label when you want the visible text
to be different from the autogenerated visible text. See How a
Name Appears.
In Java SE 1.2 only, the name but not the label automatically
appears in <code> HTML tags. Starting with Java SE 1.2.2, the
<code> tag is always included around the visible text, whether
or not a label is used.
o package.class#member is any valid program element name that is
referenced, such as a package, class, interface, constructor,
method or field name, except that the character ahead of the
member name should be a number sign (#). The class represents
any top-level or nested class or interface. The member
represents any constructor, method, or field (not a nested
class or interface). If this name is in the documented
classes, then the javadoc command create a link to it. To
create links to external referenced classes, use the -link
option. Use either of the other two @see tag forms to refer to
the documentation of a name that does not belong to a
referenced class. See Specify a Name.
Note: External referenced classes are classes that are not
passed into the javadoc command on the command line. Links in
the generated documentation to external referenced classes are
called external references or external links. For example, if
you run the javadoc command on only the java.awt package, then
any class in java.lang, such as Object, is an external
referenced class. Use the -link and -linkoffline options to
link to external referenced classes. The source comments of
external referenced classes are not available to the javadoc
command run.
o label is optional text that is visible as the link label. The
label can contain white space. If label is omitted, then
package.class.member appears, suitably shortened relative to
the current class and package. See How a Name Appears.
o A space is the delimiter between package.class#member and
label. A space inside parentheses does not indicate the start
of a label, so spaces can be used between parameters in a
method.
In the following example, an @see tag (in the Character class) refers
to the equals method in the String class. The tag includes both
arguments: the name String#equals(Object) and the label equals.
/**
* @see String#equals(Object) equals
*/
The standard doclet produces HTML that is similar to:
<dl>
<dt><b>See Also:</b>
<dd><a href="../../java/lang/String#equals(java.lang.Object)"><code>equals<code></a>
</dl>
The previous code looks similar to the following in a browser, where
the label is the visible link text:
See Also:
equals
Specify a Name
This package.class#member name can be either fully qualified, such as
java.lang.String#toUpperCase() or not, such as String#toUpperCase() or
#toUpperCase(). If the name is less than fully qualified, then the
javadoc command uses the standard Java compiler search order to find
it. See Search Order for the @see Tag. The name can contain white space
within parentheses, such as between method arguments.The advantage to
providing shorter, partially qualified names is that they are shorter
to type and there is less clutter in the source code. The following
listing shows the different forms of the name, where Class can be a
class or interface; Type can be a class, interface, array, or
primitive; and method can be a method or constructor.
Typical forms for @see package.class#member
Referencing a member of the current class
@see #field
@see #method(Type, Type,...)
@see #method(Type argname, Type argname,...)
@see #constructor(Type, Type,...)
@see #constructor(Type argname, Type argname,...)
Referencing another class in the current or imported packages
@see Class#field
@see Class#method(Type, Type,...)
@see Class#method(Type argname, Type argname,...)
@see Class#constructor(Type, Type,...)
@see Class#constructor(Type argname, Type argname,...)
@see Class.NestedClass
@see Class
Referencing an element in another package (fully qualified)
@see package.Class#field
@see package.Class#method(Type, Type,...)
@see package.Class#method(Type argname, Type argname,...)
@see package.Class#constructor(Type, Type,...)
@see package.Class#constructor(Type argname, Type argname,...)
@see package.Class.NestedClass
@see package.Class
@see package
Notes about the previous listing:
o The first set of forms with no class or package causes the javadoc
command to search only through the current class hierarchy. It finds
a member of the current class or interface, one of its superclasses
or superinterfaces, or one of its enclosing classes or interfaces
(search Items 1-3). It does not search the rest of the current
package or other packages (search Items 4-5). See Search Order for
the @see Tag.
o If any method or constructor is entered as a name with no
parentheses, such as getValue, and if there is no field with the same
name, then the javadoc command still creates a link to the method. If
this method is overloaded, then the javadoc command links to the
first method its search encounters, which is unspecified.
o Nested classes must be specified as outer.inner, not simply inner,
for all forms.
o As stated, the number sign (#), rather than a dot (.) separates a
member from its class. This enables the javadoc command to resolve
ambiguities, because the dot also separates classes, nested classes,
packages, and subpackages. However, the javadoc command properly
parses a dot when there is no ambiguity, but prints a warning to
alert you.
Search Order for the @see Tag
The javadoc command processes an @see tag that appears in a source
file, package file, or overview file. In the latter two files, you must
fully qualify the name you supply with the @see tag. In a source file,
you can specify a name that is fully qualified or partially qualified.
The following is the search order for the @see tag.
1. The current class or interface.
2. Any enclosing classes and interfaces searching the closest first.
3. Any superclasses and superinterfaces, searching the closest first.
4. The current package.
5. Any imported packages, classes, and interfaces, searching in the
order of the import statement.
The javadoc command continues to search recursively through Items 1-3
for each class it encounters until it finds a match. That is, after it
searches through the current class and its enclosing class E, it
searches through the superclasses of E before the enclosing classes of
E. In Items 4 and 5, the javadoc command does not search classes or
interfaces within a package in any specified order (that order depends
on the particular compiler). In Item 5, the javadoc command searches in
java.lang because that is imported by all programs.
When the javadoc command encounters an @see tag in a source file that
is not fully qualified, it searches for the specified name in the same
order as the Java compiler would, except the javadoc command does not
detect certain name space ambiguities because it assumes the source
code is free of these errors. This search order is formally defined in
the Java Language Specification. The javadoc command searches for that
name through all related and imported classes and packages. In
particular, it searches in this order:
1. The current class or interface.
2. Any enclosing classes and interfaces, searching the closest first.
3. Any superclasses and superinterfaces, searching the closest first.
4. The current package.
5. Any imported packages, classes, and interfaces, searching in the
order of the import statements.
The javadoc command does not necessarily look in subclasses, nor will
it look in other packages even when their documentation is being
generated in the same run. For example, if the @see tag is in the
java.awt.event.KeyEvent class and refers to a name in the java.awt
package, then the javadoc command does not look in that package unless
that class imports it.
How a Name Appears
If label is omitted, then package.class.member appears. In general, it
is suitably shortened relative to the current class and package.
Shortened means the javadoc command displays only the minimum name
necessary. For example, if the String.toUpperCase() method contains
references to a member of the same class and to a member of a different
class, then the class name is displayed only in the latter case, as
shown in the following listing. Use the -noqualifier option to globally
remove the package names.
Type of reference: The @see tag refers to a member of the same class,
same package
Example in: @see String#toLowerCase()
Appears as: toLowerCase() - omits the package and class names
Type of reference: The @see tag refers to a member of a different
class, same package
Example in: @see Character#toLowerCase(char)
Appears as: Character.toLowerCase(char) - omits the package name,
includes the class name
Type of reference: The @see tag refers to a member of a different
class, different package
Example in: @see java.io.File#exists()
Appears as: java.io.File.exists() - includes the package and class
names
Examples of the @see Tag
The comment to the right shows how the name appears when the @see tag
is in a class in another package, such as java.applet.Applet. See @see
in How to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@see
See also:
@see java.lang.String // String
@see java.lang.String The String class // The String class
@see String // String
@see String#equals(Object) // String.equals(Object)
@see String#equals // String.equals(java.lang.Object)
@see java.lang.Object#wait(long) // java.lang.Object.wait(long)
@see Character#MAX_RADIX // Character.MAX_RADIX
@see <a href="spec.html">Java Spec</a> // Java Spec
@see "The Java Programming Language" // "The Java Programming Language"
Note: You can extend the @see tag to link to classes not being
documented with the -link option.
@serial field-description | include | exclude
Introduced in JDK 1.2
Used in the documentation comment for a default serializable
field. See Documenting Serializable Fields and Data for a Class
at
http://docs.oracle.com/javase/8/docs/platform/serialization/spec/serial-
arch.html#5251
See also Oracle's Criteria for Including Classes in the
Serialized Form Specification at
http://www.oracle.com/technetwork/java/javase/documentation/serialized-
criteria-137781.html
An optional field-description should explain the meaning of the
field and list the acceptable values. When needed, the
description can span multiple lines. The standard doclet adds
this information to the serialized form page. See Cross-
Reference Pages.
If a serializable field was added to a class after the class was
made serializable, then a statement should be added to its main
description to identify at which version it was added.
The include and exclude arguments identify whether a class or
package should be included or excluded from the serialized form
page. They work as follows:
o A public or protected class that implements Serializable is
included unless that class (or its package) is marked with the
@serial exclude tag.
o A private or package-private class that implements
Serializable is excluded unless that class (or its package) is
marked with the @serial include tag.
For example, the javax.swing package is marked with the @serialexclude
tag in package.html or package-info.java. The public class
java.security.BasicPermission is marked with the @serial exclude tag.
The package-private class java.util.PropertyPermissionCollection is
marked with the @serial include tag.
The @serial tag at the class level overrides the @serial tag at the
package level.
@serialData data-description
Introduced in JDK 1.2
Uses the data description value to document the types and order
of data in the serialized form. This data includes the optional
data written by the writeObject method and all data (including
base classes) written by the Externalizable.writeExternal
method.
The @serialData tag can be used in the documentation comment for
the writeObject, readObject, writeExternal, readExternal,
writeReplace, and readResolve methods.
@serialField field-namefield-typefield-description
Introduced in JDK 1.2
Documents an ObjectStreamField component of the
serialPersistentFields member of a Serializable class. Use one
@serialField tag for each ObjectStreamField component.
@since since-text
Introduced in JDK 1.1
Adds a Since heading with the specified since-text value to the
generated documentation. The text has no special internal
structure. This tag is valid in any documentation comment:
overview, package, class, interface, constructor, method, or
field. This tag means that this change or feature has existed
since the software release specified by the since-text value,
for example: @since 1.5.
For Java platform source code, the @since tag indicates the
version of the Java platform API specification, which is not
necessarily when the source code was added to the reference
implementation. Multiple @since tags are allowed and are treated
like multiple @author tags. You could use multiple tags when the
program element is used by more than one API.
@throws class-namedescription
Introduced in JDK 1.2
Behaves the same as the @exception tag. See @throws in How to
Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@exception
The @throws tag adds a Throws subheading to the generated
documentation, with the class-name and description text. The
class-name is the name of the exception that might be thrown by
the method. This tag is valid only in the documentation comment
for a method or constructor. If this class is not fully
specified, then the javadoc command uses the search order to
look up this class. Multiple @throws tags can be used in a
specified documentation comment for the same or different
exceptions. See Search Order for the @see Tag.
To ensure that all checked exceptions are documented, when an
@throws tag does not exist for an exception in the throws
clause, the javadoc command adds that exception to the HTML
output (with no description) as though it were documented with
the @throws tag.
The @throws documentation is copied from an overridden method to
a subclass only when the exception is explicitly declared in the
overridden method. The same is true for copying from an
interface method to an implementing method. You can use the
{@inheritDoc} tag to force the @throws tag to inherit
documentation.
{@value package.class#field}
Introduced in JDK 1.4
Displays constant values. When the {@value} tag is used without
an argument in the documentation comment of a static field, it
displays the value of that constant:
/**
* The value of this constant is {@value}.
*/
public static final String SCRIPT_START = "<script>"
When used with the argument package.class#field in any
documentation comment, he {@value} tag displays the value of the
specified constant:
/**
* Evaluates the script starting with {@value #SCRIPT_START}.
*/
public String evalScript(String script) {}
The argument package.class#field takes a form similar to that of
the @see tag argument, except that the member must be a static
field.
The values of these constants are also displayed in Constant
Field Values at
http://docs.oracle.com/javase/8/docs/api/constant-values.html
@version version-text
Introduced in JDK 1.0
Adds a Version subheading with the specified version-text value
to the generated documents when the -version option is used.
This tag is intended to hold the current release number of the
software that this code is part of, as opposed to the@since tag,
which holds the release number where this code was introduced.
The version-text value has no special internal structure. See
@version in How to Write Doc Comments for the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#@version
A documentation comment can contain multiple @version tags. When
it makes sense, you can specify one release number per @version
tag or multiple release numbers per tag. In the former case, the
javadoc command inserts a comma (,) and a space between the
names. In the latter case, the entire text is copied to the
generated document without being parsed. Therefore, you can use
multiple names per line when you want a localized name separator
other than a comma.
WHERE TAGS CAN BE USED
The following sections describe where tags can be used. Note that the
following tags can be used in all documentation comments: @see, @since,
@deprecated, {@link}, {@linkplain}, and {@docroot}.
OVERVIEW TAGS
Overview tags are tags that can appear in the documentation comment for
the overview page (which resides in the source file typically named
overview.html). Similar to any other documentation comments, these tags
must appear after the main description
Note: The {@link} tag has a bug in overview documents in Java SE 1.2.
The text appears correctly but has no link. The {@docRoot} tag does not
currently work in overview documents.
The overview tags are the following:
@see reference || @since since-text || @serialField field-name field-
type field-description || @author name-text || @version version-text ||
{@link package.class#member label} || {@linkplain package.class#member
label} || {@docRoot} ||
PACKAGE TAGS
Package tags are tags that can appear in the documentation comment for
a package, that resides in the source file named package.html or
package-info.java. The @serial tag can only be used here with the
include or exclude argument.
The package tags are the following:
@see reference || @since since-text || @serial field-description |
include | exclude || @author name-text || @version version-text ||
{@linkplain package.class#member label} || {@linkplain
package.class#member label} || {@docRoot} ||
CLASS AND INTERFACE TAGS
The following are tags that can appear in the documentation comment for
a class or interface. The @serial tag can only be used within the
documentation for a class or interface with an include or exclude
argument.
@see reference || @since since-text || @deprecated deprecated-text ||
@serial field-description | include | exclude || @author name-text ||
@version version-text || {@link package.class#member label} ||
{@linkplain package.class#member label} || {@docRoot} ||
Class comment example:
/**
* A class representing a window on the screen.
* For example:
* <pre>
* Window win = new Window(parent);
* win.show();
* </pre>
*
* @author Sami Shaio
* @version 1.13, 06/08/06
* @see java.awt.BaseWindow
* @see java.awt.Button
*/
class Window extends BaseWindow {
...
}
FIELD TAGS
These tags can appear in fields:
@see reference || @since since-text || @deprecated deprecated-text ||
@serial field-description | include | exclude || @serialField field-
name field-type field-description || {@link package.class#member label}
|| {@linkplain package.class#member label} || {@docRoot} || {@value
package.class#field}
Field comment example:
/**
* The X-coordinate of the component.
*
* @see #getLocation()
*/
int x = 1263732;
CONSTRUCTOR AND METHOD TAGS
The following tags can appear in the documentation comment for a
constructor or a method, except for the @return tag, which cannot
appear in a constructor, and the {@inheritDoc} tag, which has
restrictions.
@see reference || @since since-text || @deprecated deprecated-text ||
@param parameter-name description || @return description || @throws
class-name description || @exception class-name description ||
@serialData data-description || {@link package.class#member label} ||
{@linkplain package.class#member label} || {@inheritDoc} || {@docRoot}
Note: The @serialData tag can only be used in the documentation comment
for the writeObject, readObject, writeExternal, readExternal,
writeReplace, and readResolve methods.
Method comment example:
/**
* Returns the character at the specified index. An index
* ranges from <code>0</code> to <code>length() - 1</code>
*
* @param index the index of the desired character.
* @return the desired character.
* @exception StringIndexOutOfRangeException
* if the index is not in the range <code>0</code>
* to <code>length()-1</code>
* @see java.lang.Character#charValue()
*/
public char charAt(int index) {
...
}
OPTIONS
The javadoc command uses doclets to determine its output. The javadoc
command uses the default standard doclet unless a custom doclet is
specified with the -doclet option. The javadoc command provides a set
of command-line options that can be used with any doclet. These options
are described in Javadoc Options. The standard doclet provides an
additional set of command-line options that are described in Standard
Doclet Options. All option names are not case-sensitive, but their
arguments are case-sensitive.
o See also Javadoc Options
o See also Standard Doclet Options
The options are:
-1.1 || -author || -bootclasspath classpathlist || -bottom text ||
-breakiterator || -charset name || -classpath classpathlist || -d
directory || -docencoding name || -docfilesubdirs || -doclet class ||
-docletpath classpathlist || -doctitle title || -encoding || -exclude
packagename1:packagename2:... || -excludedocfilessubdir name1:name2 ||
-extdirs dirist || -footer footer || -group groupheading
packagepattern:packagepattern || -header header || -help || -helpfile
path\filename || -Jflag || -javafx ||-keywords || -link extdocURL ||
-linkoffline extdocURL packagelistLoc || -linksource || -locale
language_country_variant || -nocomment || -nodeprecated ||
-nodeprecatedlist || -nohelp || -noindex || -nonavbar || -noqualifier
all | packagename1:packagename2... || -nosince || -notimestamp ||
-notree || -overview path/filename || -package || -private ||
-protected || -public || -quiet || -serialwarn || -source release ||
-sourcepath sourcepathlist || -sourcetab tablength || -splitindex ||
-stylesheet path/filename || -subpackages package1:package2:... || -tag
tagname:Xaoptcmf:"taghead" || -taglet class || -tagletpath
tagletpathlist || -title title || -top || -use || -verbose || -version
|| -windowtitle title
The following options are the core Javadoc options that are available
to all doclets. The standard doclet provides the rest of the doclets:
-bootclasspath, -breakiterator, -classpath, -doclet, -docletpath,
-encoding, -exclude, -extdirs, -help, -locale, -overview, -package,
-private, -protected, -public, -quiet, -source, -sourcepath,
-subpackages, and -verbose.
JAVADOC OPTIONS
-overview path/filename
Specifies that the javadoc command should retrieve the text for
the overview documentation from the source file specified by the
path/filenameand place it on the Overview page (overview-
summary.html). The path/filenameis relative to the current
directory.
While you can use any name you want for the filename value and
place it anywhere you want for the path, it is typical to name
it overview.html and place it in the source tree at the
directory that contains the topmost package directories. In this
location, no path is needed when documenting packages, because
the -sourcepath option points to this file.
For example, if the source tree for the java.lang package is
/src/classes/java/lang/, then you could place the overview file
at /src/classes/overview.html
See Real-World Examples.
For information about the file specified by path/filename,see
Overview Comment Files.
The overview page is created only when you pass two or more
package names to the javadoc command. For a further explanation,
see HTML Frames. The title on the overview page is set by
-doctitle.
-Xdoclint:(all|none|[-]<group>)
Reports warnings for bad references, lack of accessibility and
missing Javadoc comments, and reports errors for invalid Javadoc
syntax and missing HTML tags.
This option enables the javadoc command to check for all
documentation comments included in the generated output. As
always, you can select which items to include in the generated
output with the standard options -public, -protected, -package
and -private.
When the -Xdoclint is enabled, it reports issues with messages
similar to the javac command. The javadoc command prints a
message, a copy of the source line, and a caret pointing at the
exact position where the error was detected. Messages may be
either warnings or errors, depending on their severity and the
likelihood to cause an error if the generated documentation were
run through a validator. For example, bad references or missing
Javadoc comments do not cause the javadoc command to generate
invalid HTML, so these issues are reported as warnings. Syntax
errors or missing HTML end tags cause the javadoc command to
generate invalid output, so these issues are reported as errors.
By default, the -Xdoclint option is enabled. Disable it with the
option -Xdoclint:none.
Change what the -Xdoclint option reports with the following
options:
o -Xdoclint none : disable the -Xdoclint option
o -Xdoclintgroup : enable group checks
o -Xdoclint all : enable all groups of checks
o -Xdoclint all,-group : enable all except group checks
The variable group has one of the following values:
o accessibility : Checks for the issues to be detected by an
accessibility checker (for example, no caption or summary
attributes specified in a <table> tag).
o html : Detects high-level HTML issues, like putting block
elements inside inline elements, or not closing elements that
require an end tag. The rules are derived from theHTML 4.01
Specification. This type of check enables the javadoc command
to detect HTML issues that many browsers might accept.
o missing : Checks for missing Javadoc comments or tags (for
example, a missing comment or class, or a missing @return tag
or similar tag on a method).
o reference : Checks for issues relating to the references to
Java API elements from Javadoc tags (for example, item not
found in @see , or a bad name after @param).
o syntax : Checks for low level issues like unescaped angle
brackets (< and >) and ampersands (&) and invalid Javadoc
tags.
You can specify the -Xdoclint option multiple times to enable the
option to check errors and warnings in multiple categories.
Alternatively, you can specify multiple error and warning categories by
using the preceding options. For example, use either of the following
commands to check for the HTML, syntax, and accessibility issues in the
file filename.
javadoc -Xdoclint:html -Xdoclint:syntax -Xdoclint:accessibility filename
javadoc -Xdoclint:html,syntax,accessibility filename
Note: The javadoc command does not guarantee the completeness of these
checks. In particular, it is not a full HTML compliance checker. The
goal of the -Xdoclint option is to enable the javadoc command to report
majority of common errors.
The javadoc command does not attempt to fix invalid input, it just
reports it.
-public
Shows only public classes and members.
-protected
Shows only protected and public classes and members. This is the
default.
-package
Shows only package, protected, and public classes and members.
-private
Shows all classes and members.
-help
Displays the online help, which lists all of the javadoc and
doclet command-line options.
-doclet class
Specifies the class file that starts the doclet used in
generating the documentation. Use the fully qualified name. This
doclet defines the content and formats the output. If the
-doclet option is not used, then the javadoc command uses the
standard doclet for generating the default HTML format. This
class must contain the start(Root) method. The path to this
starting class is defined by the -docletpath option. See Doclet
Overview at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/doclet/overview.html
-docletpath classpathlist
Specifies the path to the doclet starting class file (specified
with the -doclet option) and any JAR files it depends on. If the
starting class file is in a JAR file, then this option specifies
the path to that JAR file. You can specify an absolute path or a
path relative to the current directory. If classpathlist
contains multiple paths or JAR files, then they should be
separated with a colon (:) on Oracle Solaris and a semi-colon
(;) on Windows. This option is not necessary when the doclet
starting class is already in the search path. See Doclet
Overview at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/doclet/overview.html
-1.1
Removed from Javadoc 1.4 with no replacement. This option
created documentation with the appearance and functionality of
documentation generated by Javadoc 1.1 (it never supported
nested classes). If you need this option, then use Javadoc 1.2
or 1.3 instead.
-source release
Specifies the release of source code accepted. The following
values for the release parameter are allowed. Use the value of
release that corresponds to the value used when you compile code
with the javac command.
o Release Value: 1.5. The javadoc command accepts code
containing generics and other language features introduced in
JDK 1.5. The compiler defaults to the 1.5 behavior when the
-source option is not used.
o Release Value: 1.4. The javadoc command accepts code
containing assertions, which were introduced in JDK 1.4.
o Release Value: 1.3. The javadoc command does not support
assertions, generics, or other language features introduced
after JDK 1.3.
-sourcepath sourcepathlist
Specifies the search paths for finding source files when passing
package names or the -subpackages option into the javadoc
command. Separate multiple paths with a colon (:). The javadoc
command searches all subdirectories of the specified paths. Note
that this option is not only used to locate the source files
being documented, but also to find source files that are not
being documented, but whose comments are inherited by the source
files being documented.
You can use the -sourcepath option only when passing package
names into the javadoc command. This will not locate source
files passed into the javadoc command. To locate source files,
change to that directory or include the path ahead of each file,
as shown at Document One or More Classes. If you omit
-sourcepath, then the javadoc command uses the class path to
find the source files (see -classpath). The default -sourcepath
is the value of class path. If -classpath is omitted and you
pass package names into the javadoc command, then the javadoc
command searches in the current directory and subdirectories for
the source files.
Set sourcepathlist to the root directory of the source tree for
the package you are documenting.
For example, suppose you want to document a package called
com.mypackage, whose source files are located
at:/home/user/src/com/mypackage/*.java. Specify the sourcepath
to /home/user/src, the directory that contains com\mypackage,
and then supply the package name, as follows:
javadoc -sourcepath /home/user/src/ com.mypackage
Notice that if you concatenate the value of sourcepath and the
package name together and change the dot to a slash (/), then
you have the full path to the package:
/home/user/src/com/mypackage
To point to two source paths:
javadoc -sourcepath /home/user1/src:/home/user2/src com.mypackage
-classpath classpathlist
Specifies the paths where the javadoc command searches for
referenced classes These are the documented classes plus any
classes referenced by those classes. Separate multiple paths
with a colon (:). The javadoc command searches all
subdirectories of the specified paths. Follow the instructions
in the class path documentation for specifying the classpathlist
value.
If you omit -sourcepath, then the javadoc command uses
-classpath to find the source files and class files (for
backward compatibility). If you want to search for source and
class files in separate paths, then use both -sourcepath and
-classpath.
For example, if you want to document com.mypackage, whose source
files reside in the directory /home/user/src/com/mypackage, and
if this package relies on a library in /home/user/lib, then you
would use the following command:
javadoc -sourcepath /home/user/lib -classpath /home/user/src com.mypackage
Similar to other tools, if you do not specify -classpath, then
the javadoc command uses the CLASSPATH environment variable when
it is set. If both are not set, then the javadoc command
searches for classes from the current directory.
For an in-depth description of how the javadoc command uses
-classpath to find user classes as it relates to extension
classes and bootstrap classes, see How Classes Are Found at
http://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html
A class path element that contains a base name of * is
considered equivalent to specifying a list of all the files in
the directory with the extension .jar or .JAR.
For example, if directory mydir contains a.jar and b.JAR, then
the class path element foo/* is expanded to a A.jar:b.JAR,
except that the order of JAR files is unspecified. All JAR files
in the specified directory including hidden files are included
in the list. A class path entry that consists of * expands to a
list of all the jar files in the current directory. The
CLASSPATH environment variable is similarly expanded. Any class
path wildcard expansion occurs before the Java Virtual Machine
(JVM) starts. No Java program ever sees unexpanded wild cards
except by querying the environment, for example, by calling
System.getenv("CLASSPATH").
-subpackages package1:package2:...
Generates documentation from source files in the specified
packages and recursively in their subpackages. This option is
useful when adding new subpackages to the source code because
they are automatically included. Each package argument is any
top-level subpackage (such as java) or fully qualified package
(such as javax.swing) that does not need to contain source
files. Arguments are separated by colons on all operating
systems. Wild cards are not allowed. Use -sourcepath to specify
where to find the packages. This option does not process source
files that are in the source tree but do not belong to the
packages. See Process Source Files.
For example, the following command generates documentation for
packages named java and javax.swing and all of their
subpackages.
javadoc -d docs -sourcepath /home/user/src -subpackages java:javax.swing
-exclude packagename1:packagename2:...
Unconditionally excludes the specified packages and their
subpackages from the list formed by -subpackages. It excludes
those packages even when they would otherwise be included by
some earlier or later -subpackages option.
The following example would include java.io, java.util, and
java.math (among others), but would exclude packages rooted at
java.net and java.lang. Notice that this example excludes
java.lang.ref, which is a subpackage of java.lang.
javadoc -sourcepath /home/user/src -subpackages java -exclude
java.net:java.lang
-bootclasspath classpathlist
Specifies the paths where the boot classes reside. These are
typically the Java platform classes. The bootclasspath is part
of the search path the javadoc command uses to look up source
and class files. For more information, see How Classes Are Found
at
http://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html
Separate directories in the classpathlist parameters with
semicolons (;) for Windows and colons (:) for Oracle Solaris.
-extdirs dirist
Specifies the directories where extension classes reside. These
are any classes that use the Java Extension mechanism. The
extdirs option is part of the search path the javadoc command
uses to look up source and class files. See the -classpath
option for more information. Separate directories in dirlist
with semicolons (;) for Windows and colons (:) for Oracle
Solaris.
-verbose
Provides more detailed messages while the javadoc command runs.
Without the verbose option, messages appear for loading the
source files, generating the documentation (one message per
source file), and sorting. The verbose option causes the
printing of additional messages that specify the number of
milliseconds to parse each Java source file.
-quiet
Shuts off messages so that only the warnings and errors appear
to make them easier to view. It also suppresses the version
string.
-breakiterator
Uses the internationalized sentence boundary of
java.text.BreakIterator to determine the end of the first
sentence in the main description of a package, class, or member
for English. All other locales already use the BreakIterator
class, rather than an English language, locale-specific
algorithm. The first sentence is copied to the package, class,
or member summary and to the alphabetic index. From JDK 1.2 and
later, the BreakIterator class is used to determine the end of a
sentence for all languages except for English. Therefore, the
-breakiterator option has no effect except for English from 1.2
and later. English has its own default algorithm:
o English default sentence-break algorithm. Stops at a period
followed by a space or an HTML block tag, such as <P>.
o Breakiterator sentence-break algorithm. Stops at a period,
question mark, or exclamation point followed by a space when
the next word starts with a capital letter. This is meant to
handle most abbreviations (such as "The serial no. is valid",
but will not handle "Mr. Smith"). The -breakiterator option
does not stop at HTML tags or sentences that begin with
numbers or symbols. The algorithm stops at the last period in
../filename, even when embedded in an HTML tag.
In Java SE 1.5 the -breakiterator option warning messages are removed,
and the default sentence-break algorithm is unchanged. If you have not
modified your source code to eliminate the -breakiterator option
warnings in Java SE 1.4.x, then you do not have to do anything. The
warnings go away starting with Java SE 1.5.0.
-locale language_country_variant
Specifies the locale that the javadoc command uses when it
generates documentation. The argument is the name of the locale,
as described in java.util.Locale documentation, such as en_US
(English, United States) or en_US_WIN (Windows variant).
Note: The -locale option must be placed ahead (to the left) of
any options provided by the standard doclet or any other doclet.
Otherwise, the navigation bars appear in English. This is the
only command-line option that depends on order. See Standard
Doclet Options.
Specifying a locale causes the javadoc command to choose the
resource files of that locale for messages such as strings in
the navigation bar, headings for lists and tables, help file
contents, comments in the stylesheet.css file, and so on. It
also specifies the sorting order for lists sorted
alphabetically, and the sentence separator to determine the end
of the first sentence. The -locale option does not determine the
locale of the documentation comment text specified in the source
files of the documented classes.
-encoding
Specifies the encoding name of the source files, such as
EUCJIS/SJIS. If this option is not specified, then the platform
default converter is used. See also the-docencoding name and
-charset name options.
-Jflag
Passes flag directly to the Java Runtime Environment (JRE) that
runs the javadoc command. For example, if you must ensure that
the system sets aside 32 MB of memory in which to process the
generated documentation, then you would call the -Xmx option as
follows: javadoc -J-Xmx32m -J-Xms32m com.mypackage. Be aware
that -Xms is optional because it only sets the size of initial
memory, which is useful when you know the minimum amount of
memory required.
There is no space between the J and the flag.
Use the -version option to find out what version of the javadoc
command you are using. The version number of the standard doclet
appears in its output stream. See Running the Javadoc Command.
javadoc -J-version
java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode)
-javafx
Generates HTML documentation using the JavaFX extensions to the
standard doclet. The generated documentation includes a Property
Summary section in addition to the other summary sections
generated by the standard Java doclet. The listed properties are
linked to the sections for the getter and setter methods of each
property.
If there are no documentation comments written explicitly for
getter and setter methods, the documentation comments from the
property method are automatically copied to the generated
documentation for these methods. This option also adds a new
@defaultValue tag that allows documenting the default value for
a property.
Example:
javadoc -javafx MyClass.java -d testdir
STANDARD DOCLET OPTIONS
-d directory
Specifies the destination directory where the javadoc command
saves the generated HTML files. If you omit the -d option, then
the files are saved to the current directory. The directory
value can be absolute or relative to the current working
directory. As of Java SE 1.4, the destination directory is
automatically created when the javadoc command runs.
For example, the following command generates the documentation
for the package com.mypackage and saves the results in the
/user/doc/ directory: javadoc -d/user/doc/com.mypackage.
-use
Includes one Use page for each documented class and package. The
page describes what packages, classes, methods, constructors and
fields use any API of the specified class or package. Given
class C, things that use class C would include subclasses of C,
fields declared as C, methods that return C, and methods and
constructors with parameters of type C. For example, you can
look at the Use page for the String type. Because the getName
method in the java.awt.Font class returns type String, the
getName method uses String and so the getName method appears on
the Use page for String.This documents only uses of the API, not
the implementation. When a method uses String in its
implementation, but does not take a string as an argument or
return a string, that is not considered a use of String.To
access the generated Use page, go to the class or package and
click the Use link in the navigation bar.
-version
Includes the @version text in the generated docs. This text is
omitted by default. To find out what version of the javadoc
command you are using, use the -J-version option.
-author
Includes the @author text in the generated docs.
-splitindex
Splits the index file into multiple files, alphabetically, one
file per letter, plus a file for any index entries that start
with non-alphabetical symbols.
-windowtitle title
Specifies the title to be placed in the HTML <title> tag. The
text specified in the title tag appears in the window title and
in any browser bookmarks (favorite places) that someone creates
for this page. This title should not contain any HTML tags
because the browser does not interpret them correctly. Use
escape characters on any internal quotation marks within the
title tag. If the -windowtitle option is omitted, then the
javadoc command uses the value of the -doctitle option for the
-windowtitle option. For example, javadoc -windowtitle "Java SE
Platform" com.mypackage.
-doctitle title
Specifies the title to place near the top of the overview
summary file. The text specified in the title tag is placed as a
centered, level-one heading directly beneath the top navigation
bar. The title tag can contain HTML tags and white space, but
when it does, you must enclose the title in quotation marks.
Internal quotation marks within the title tag must be escaped.
For example, javadoc -header "<b>Java Platform </b><br>v1.4"
com.mypackage.
-title title
No longer exists. It existed only in Beta releases of Javadoc
1.2. It was renamed to -doctitle. This option was renamed to
make it clear that it defines the document title, rather than
the window title.
-header header
Specifies the header text to be placed at the top of each output
file. The header is placed to the right of the upper navigation
bar. The header can contain HTML tags and white space, but when
it does, the header must be enclosed in quotation marks. Use
escape characters for internal quotation marks within a header.
For example, javadoc -header "<b>Java Platform </b><br>v1.4"
com.mypackage.
-footer footer
Specifies the footer text to be placed at the bottom of each
output file. The footer value is placed to the right of the
lower navigation bar. The footer value can contain HTML tags and
white space, but when it does, the footer value must be enclosed
in quotation marks. Use escape characters for any internal
quotation marks within a footer.
-top
Specifies the text to be placed at the top of each output file.
-bottom text
Specifies the text to be placed at the bottom of each output
file. The text is placed at the bottom of the page, underneath
the lower navigation bar. The text can contain HTML tags and
white space, but when it does, the text must be enclosed in
quotation marks. Use escape characters for any internal
quotation marks within text.
-link extdocURL
Creates links to existing Javadoc-generated documentation of
externally referenced classes. The extdocURL argument is the
absolute or relative URL of the directory that contains the
external Javadoc-generated documentation you want to link to.
You can specify multiple -link options in a specified javadoc
command run to link to multiple documents.
The package-list file must be found in this directory
(otherwise, use the -linkoffline option). The javadoc command
reads the package names from the package-list file and links to
those packages at that URL. When the javadoc command runs, the
extdocURL value is copied into the <A HREF> links that are
created. Therefore, extdocURL must be the URL to the directory,
and not to a file. You can use an absolute link for extdocURL to
enable your documents to link to a document on any web site, or
you can use a relative link to link only to a relative location.
If you use a relative link, then the value you pass in should be
the relative path from the destination directory (specified with
the -d option) to the directory containing the packages being
linked to.When you specify an absolute link, you usually use an
HTTP link. However, if you want to link to a file system that
has no web server, then you can use a file link. Use a file link
only when everyone who wants to access the generated
documentation shares the same file system.In all cases, and on
all operating systems, use a slash as the separator, whether the
URL is absolute or relative, and http: or file: as specified in
the URL Memo: Uniform Resource Locators at
http://www.ietf.org/rfc/rfc1738.txt
-link http://<host>/<directory>/<directory>/.../<name>
-link file://<host>/<directory>/<directory>/.../<name>
-link <directory>/<directory>/.../<name>
Differences between the -linkoffline and -link options
Use the -link option in the following cases:
o When you use a relative path to the external API document.
o When you use an absolute URL to the external API document if your
shell lets you open a connection to that URL for reading.
Use the -linkoffline option when you use an absolute URL to the
external API document, if your shell does not allow a program to open a
connection to that URL for reading. This can occur when you are behind
a firewall and the document you want to link to is on the other side.
Example 1 Absolute Link to External Documents
Use the following command if you want to link to the java.lang, java.io
and other Java platform packages, shown at
http://docs.oracle.com/javase/8/docs/api/index.html
javadoc -link http://docs.oracle.com/javase/8/docs/api/ com.mypackage
The command generates documentation for the package com.mypackage with
links to the Java SE packages. The generated documentation contains
links to the Object class, for example, in the class trees. Other
options, such as the -sourcepath and -d options, are not shown.
Example 2 Relative Link to External Documents
In this example, there are two packages with documents that are
generated in different runs of the javadoc command, and those documents
are separated by a relative path. The packages are com.apipackage, an
API, and com.spipackage, an Service Provide Interface (SPI). You want
the documentation to reside in docs/api/com/apipackage and
docs/spi/com/spipackage. Assuming that the API package documentation is
already generated, and that docs is the current directory, you document
the SPI package with links to the API documentation by running: javadoc
-d ./spi -link ../api com.spipackage.
Notice the -link option is relative to the destination directory
(docs/spi).
Notes
The -link option lets you link to classes referenced to by your code,
but not documented in the current javadoc command run. For these links
to go to valid pages, you must know where those HTML pages are located
and specify that location with extdocURL. This allows third-party
documentation to link to java.* documentation at
http://docs.oracle.com.Omit the -link option when you want the javadoc
command to create links only to APIs within the documentation it is
generating in the current run. Without the -link option, the javadoc
command does not create links to documentation for external references
because it does not know whether or where that documentation exists.The
-link option can create links in several places in the generated
documentation. See Process Source Files. Another use is for cross-links
between sets of packages: Execute the javadoc command on one set of
packages, then run the javadoc command again on another set of
packages, creating links both ways between both sets.
How to Reference a Class
For a link to an externally referenced class to appear (and not just
its text label), the class must be referenced in the following way. It
is not sufficient for it to be referenced in the body of a method. It
must be referenced in either an import statement or in a declaration.
Here are examples of how the class java.io.File can be referenced:
In any kind of import statement. By wildcard import, import explicitly
by name, or automatically import for java.lang.*.
In Java SE 1.3.n and 1.2.n, only an explicit import by name works. A
wildcard import statement does not work, nor does the automatic import
java.lang.*.
In a declaration: void mymethod(File f) {}
The reference can be in the return type or parameter type of a method,
constructor, field, class, or interface, or in an implements, extends,
or throws statement.
An important corollary is that when you use the -link option, there can
be many links that unintentionally do not appear due to this
constraint. The text would appear without being a link. You can detect
these by the warnings they emit. The simplest way to properly reference
a class and add the link would be to import that class.
Package List
The -link option requires that a file named package-list, which is
generated by the javadoc command, exists at the URL you specify with
the -link option. The package-list file is a simple text file that
lists the names of packages documented at that location. In the earlier
example, the javadoc command searches for a file named package-list at
the specified URL, reads in the package names, and links to those
packages at that URL.
For example, the package list for the Java SE API is located at
http://docs.oracle.com/javase/8/docs/api/package-list
The package list starts as follows:
java.applet
java.awt
java.awt.color
java.awt.datatransfer
java.awt.dnd
java.awt.event
java.awt.font
and so on ....
When javadoc is run without the -link option and encounters a name that
belongs to an externally referenced class, it prints the name with no
link. However, when the -link option is used, the javadoc command
searches the package-list file at the specified extdocURL location for
that package name. When it finds the package name, it prefixes the name
with extdocURL.
For there to be no broken links, all of the documentation for the
external references must exist at the specified URLs. The javadoc
command does not check that these pages exist, but only that the
package-list exists.
Multiple Links
You can supply multiple -link options to link to any number of
externally generated documents. Javadoc 1.2 has a known bug that
prevents you from supplying more than one -link options. This was fixed
in Javadoc 1.2.2. Specify a different link option for each external
document to link to javadoc -link extdocURL1 -link extdocURL2 ... -link
extdocURLn com.mypackage where extdocURL1, extdocURL2, ... extdocURLn
point respectively to the roots of external documents, each of which
contains a file named package-list.
Cross Links
Note that bootstrapping might be required when cross-linking two or
more documents that were previously generated. If package-list does not
exist for either document when you run the javadoc command on the first
document, then the package-list does not yet exist for the second
document. Therefore, to create the external links, you must regenerate
the first document after you generate the second document.
In this case, the purpose of first generating a document is to create
its package-list (or you can create it by hand if you are certain of
the package names). Then, generate the second document with its
external links. The javadoc command prints a warning when a needed
external package-list file does not exist.
-linkoffline extdocURL packagelistLoc
This option is a variation of the -link option. They both create
links to Javadoc-generated documentation for externally
referenced classes. Use the -linkoffline option when linking to
a document on the web when the javadoc command cannot access the
document through a web connection. Use the -linkoffline option
when package-list file of the external document is not
accessible or does not exist at the extdocURL location, but does
exist at a different location that can be specified by
packageListLoc (typically local). If extdocURL is accessible
only on the World Wide Web, then the -linkoffline option removes
the constraint that the javadoc command must have a web
connection to generate documentation. Another use is as a work-
around to update documents: After you have run the javadoc
command on a full set of packages, you can run the javadoc
command again on a smaller set of changed packages, so that the
updated files can be inserted back into the original set.
Examples follow. The -linkoffline option takes two arguments.
The first is for the string to be embedded in the <a href>
links, and the second tells the -linkoffline option where to
find package-list:
o The extdocURL value is the absolute or relative URL of the
directory that contains the external Javadoc-generated
documentation you want to link to. When relative, the value
should be the relative path from the destination directory
(specified with the -d option) to the root of the packages
being linked to. For more information, see extdocURL in the
-link option.
o The packagelistLoc value is the path or URL to the directory
that contains the package-list file for the external
documentation. This can be a URL (http: or file:) or file
path, and can be absolute or relative. When relative, make it
relative to the current directory from where the javadoc
command was run. Do not include the package-list file name.
You can specify multiple -linkoffline options in a specified
javadoc command run. Before Javadoc 1.2.2, the -linkfile
options could be specified once.
Absolute Links to External Documents
You might have a situation where you want to link to the java.lang,
java.io and other Java SE packages at
http://docs.oracle.com/javase/8/docs/api/index.html
However, your shell does not have web access. In this case, do the
following:
1. Open the package-list file in a browser at
http://docs.oracle.com/javase/8/docs/api/package-list
2. Save the file to a local directory, and point to this local copy
with the second argument, packagelistLoc. In this example, the
package list file was saved to the current directory (.).
The following command generates documentation for the package
com.mypackage with links to the Java SE packages. The generated
documentation will contain links to the Object class, for example, in
the class trees. Other necessary options, such as -sourcepath, are not
shown.
javadoc -linkoffline http://docs.oracle.com/javase/8/docs/api/ . com.mypackage
Relative Links to External Documents
It is not very common to use -linkoffline with relative paths, for the
simple reason that the -link option is usually enough. When you use the
-linkoffline option, the package-list file is usually local, and when
you use relative links, the file you are linking to is also local, so
it is usually unnecessary to give a different path for the two
arguments to the -linkoffline option When the two arguments are
identical, you can use the -link option.
Create a package-list File Manually
If a package-list file does not exist yet, but you know what package
names your document will link to, then you can manually create your own
copy of this file and specify its path with packagelistLoc. An example
would be the previous case where the package list for com.spipackage
did not exist when com.apipackage was first generated. This technique
is useful when you need to generate documentation that links to new
external documentation whose package names you know, but which is not
yet published. This is also a way of creating package-list files for
packages generated with Javadoc 1.0 or 1.1, where package-list files
were not generated. Similarly, two companies can share their
unpublished package-list files so they can release their cross-linked
documentation simultaneously.
Link to Multiple Documents
You can include the -linkoffline option once for each generated
document you want to refer to:
javadoc -linkoffline extdocURL1 packagelistLoc1 -linkoffline extdocURL2
packagelistLoc2 ...
Update Documents
You can also use the -linkoffline option when your project has dozens
or hundreds of packages. If you have already run the javadoc command on
the entire source tree, then you can quickly make small changes to
documentation comments and rerun the javadoc command on a portion of
the source tree. Be aware that the second run works properly only when
your changes are to documentation comments and not to declarations. If
you were to add, remove, or change any declarations from the source
code, then broken links could show up in the index, package tree,
inherited member lists, Use page, and other places.
First, create a new destination directory, such as update, for this new
small run. In this example, the original destination directory is named
html. In the simplest example, change directory to the parent of html.
Set the first argument of the -linkoffline option to the current
directory (.) and set the second argument to the relative path to html,
where it can find package-list and pass in only the package names of
the packages you want to update:
javadoc -d update -linkoffline . html com.mypackage
When the javadoc command completes, copy these generated class pages in
update/com/package (not the overview or index) to the original files in
html/com/package.
-linksource
Creates an HTML version of each source file (with line numbers)
and adds links to them from the standard HTML documentation.
Links are created for classes, interfaces, constructors,
methods, and fields whose declarations are in a source file.
Otherwise, links are not created, such as for default
constructors and generated classes.
This option exposes all private implementation details in the
included source files, including private classes, private
fields, and the bodies of private methods, regardless of the
-public, -package, -protected, and -private options. Unless you
also use the -private option, not all private classes or
interfaces are accessible through links.
Each link appears on the name of the identifier in its
declaration. For example, the link to the source code of the
Button class would be on the word Button:
public class Button extends Component implements Accessible
The link to the source code of the getLabel method in the Button
class is on the word getLabel:
public String getLabel()
-group groupheading packagepattern:packagepattern
Separates packages on the overview page into whatever groups you
specify, one group per table. You specify each group with a
different -group option. The groups appear on the page in the
order specified on the command line. Packages are alphabetized
within a group. For a specified -group option, the packages
matching the list of packagepattern expressions appear in a
table with the heading groupheading.
o The groupheading can be any text and can include white space.
This text is placed in the table heading for the group.
o The packagepattern value can be any package name at the start
of any package name followed by an asterisk (*). The asterisk
is the only wildcard allowed and means match any characters.
Multiple patterns can be included in a group by separating
them with colons (:). If you use an asterisk in a pattern or
pattern list, then the pattern list must be inside quotation
marks, such as "java.lang*:java.util".
When you do not supply a -group option, all packages are placed in one
group with the heading Packages and appropriate subheadings. If the
subheadings do not include all documented packages (all groups), then
the remaining packages appear in a separate group with the subheading
Other Packages.
For example, the following javadoc command separates the three
documented packages into Core, Extension, and Other Packages. The
trailing dot (.) does not appear in java.lang*. Including the dot, such
as java.lang.* omits thejava.lang package.
javadoc -group "Core Packages" "java.lang*:java.util"
-group "Extension Packages" "javax.*"
java.lang java.lang.reflect java.util javax.servlet java.new
Core Packages
java.lang
java.lang.reflect
java.util
Extension Packages
javax.servlet
Other Packages
java.new
-nodeprecated
Prevents the generation of any deprecated API in the
documentation. This does what the -nodeprecatedlist option does,
and it does not generate any deprecated API throughout the rest
of the documentation. This is useful when writing code when you
do not want to be distracted by the deprecated code.
-nodeprecatedlist
Prevents the generation of the file that contains the list of
deprecated APIs (deprecated-list.html) and the link in the
navigation bar to that page. The javadoc command continues to
generate the deprecated API throughout the rest of the document.
This is useful when your source code contains no deprecated
APIs, and you want to make the navigation bar cleaner.
-nosince
Omits from the generated documents the Since sections associated
with the @since tags.
-notree
Omits the class/interface hierarchy pages from the generated
documents. These are the pages you reach using the Tree button
in the navigation bar. The hierarchy is produced by default.
-noindex
Omits the index from the generated documents. The index is
produced by default.
-nohelp
Omits the HELP link in the navigation bars at the top and bottom
of each page of output.
-nonavbar
Prevents the generation of the navigation bar, header, and
footer, that are usually found at the top and bottom of the
generated pages. The -nonavbar option has no affect on the
-bottom option. The -nonavbar option is useful when you are
interested only in the content and have no need for navigation,
such as when you are converting the files to PostScript or PDF
for printing only.
-helpfile path\filename
Specifies the path of an alternate help file path\filename that
the HELP link in the top and bottom navigation bars link to.
Without this option, the javadoc command creates a help file
help-doc.html that is hard-coded in the javadoc command. This
option lets you override the default. The file name can be any
name and is not restricted to help-doc.html. The javadoc command
adjusts the links in the navigation bar accordingly, for
example:
javadoc -helpfile /home/user/myhelp.html java.awt.
-stylesheet path/filename
Specifies the path of an alternate HTML stylesheet file. Without
this option, the javadoc command automatically creates a
stylesheet file stylesheet.css that is hard-coded in the javadoc
command. This option lets you override the default. The file
name can be any name and is not restricted to stylesheet.css,
for example:
javadoc -stylesheet file /home/user/mystylesheet.css com.mypackage
-serialwarn
Generates compile-time warnings for missing @serial tags. By
default, Javadoc 1.2.2 and later versions generate no serial
warnings. This is a reversal from earlier releases. Use this
option to display the serial warnings, which helps to properly
document default serializable fields and writeExternal methods.
-charset name
Specifies the HTML character set for this document. The name
should be a preferred MIME name as specified in the IANA
Registry, Character Sets at
http://www.iana.org/assignments/character-sets
For example, javadoc -charset "iso-8859-1" mypackage inserts the
following line in the head of every generated page:
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
This META tag is described in the HTML standard (4197265 and
4137321), HTML Document Representation, at
http://www.w3.org/TR/REC-html40/charset.html#h-5.2.2
See also the -encoding and -docencoding name options.
-docencoding name
Specifies the encoding of the generated HTML files. The name
should be a preferred MIME name as specified in the IANA
Registry, Character Sets at
http://www.iana.org/assignments/character-sets
If you omit the -docencoding option but use the -encoding
option, then the encoding of the generated HTML files is
determined by the -encoding option, for example: javadoc
-docencoding "iso-8859-1" mypackage. See also the -encoding and
-docencoding name options.
-keywords
Adds HTML keyword <META> tags to the generated file for each
class. These tags can help search engines that look for <META>
tags find the pages. Most search engines that search the entire
Internet do not look at <META> tags, because pages can misuse
them. Search engines offered by companies that confine their
searches to their own website can benefit by looking at <META>
tags. The <META> tags include the fully qualified name of the
class and the unqualified names of the fields and methods.
Constructors are not included because they are identical to the
class name. For example, the class String starts with these
keywords:
<META NAME="keywords" CONTENT="java.lang.String class">
<META NAME="keywords" CONTENT="CASE_INSENSITIVE_ORDER">
<META NAME="keywords" CONTENT="length()">
<META NAME="keywords" CONTENT="charAt()">
-tag tagname:Xaoptcmf:"taghead"
Enables the javadoc command to interpret a simple, one-argument
@tagname custom block tag in documentation comments. For the
javadoc command to spell-check tag names, it is important to
include a -tag option for every custom tag that is present in
the source code, disabling (with X) those that are not being
output in the current run.The colon (:) is always the separator.
The -tag option outputs the tag heading taghead in bold,
followed on the next line by the text from its single argument.
Similar to any block tag, the argument text can contain inline
tags, which are also interpreted. The output is similar to
standard one-argument tags, such as the @return and @author
tags. Omitting a value for taghead causes tagname to be the
heading.
Placement of tags: The Xaoptcmf arguments determine where in the
source code the tag is allowed to be placed, and whether the tag
can be disabled (using X). You can supply either a, to allow the
tag in all places, or any combination of the other letters:
X (disable tag)
a (all)
o (overview)
p (packages)
t (types, that is classes and interfaces)
c (constructors)
m (methods)
f (fields)
Examples of single tags: An example of a tag option for a tag
that can be used anywhere in the source code is: -tag todo:a:"To
Do:".
If you want the @todo tag to be used only with constructors,
methods, and fields, then you use: -tag todo:cmf:"To Do:".
Notice the last colon (:) is not a parameter separator, but is
part of the heading text. You would use either tag option for
source code that contains the @todo tag, such as: @todo The
documentation for this method needs work.
Colons in tag names: Use a backslash to escape a colon that you
want to use in a tag name. Use the -tag ejb\\:bean:a:"EJB Bean:"
option for the following documentation comment:
/**
* @ejb:bean
*/
Spell-checking tag names: Some developers put custom tags in the
source code that they do not always want to output. In these
cases, it is important to list all tags that are in the source
code, enabling the ones you want to output and disabling the
ones you do not want to output. The presence of X disables the
tag, while its absence enables the tag. This gives the javadoc
command enough information to know whether a tag it encounters
is unknown, which is probably the results of a typographical
error or a misspelling. The javadoc command prints a warning in
these cases. You can add X to the placement values already
present, so that when you want to enable the tag, you can simply
delete the X. For example, if the @todo tag is a tag that you
want to suppress on output, then you would use: -tag
todo:Xcmf:"To Do:". If you would rather keep it simple, then use
this: -tag todo:X. The syntax -tag todo:X works even when the
@todo tag is defined by a taglet.
Order of tags: The order of the -tag and -taglet options
determines the order the tags are output. You can mix the custom
tags with the standard tags to intersperse them. The tag options
for standard tags are placeholders only for determining the
order. They take only the standard tag's name. Subheadings for
standard tags cannot be altered. This is illustrated in the
following example.If the -tag option is missing, then the
position of the -taglet option determines its order. If they are
both present, then whichever appears last on the command line
determines its order. This happens because the tags and taglets
are processed in the order that they appear on the command line.
For example, if the -taglet and -tag options have the name todo
value, then the one that appears last on the command line
determines the order.
Example of a complete set of tags: This example inserts To Do
after Parameters and before Throws in the output. By using X, it
also specifies that the @example tag might be encountered in the
source code that should not be output during this run. If you
use the @argfile tag, then you can put the tags on separate
lines in an argument file similar to this (no line continuation
characters needed):
-tag param
-tag return
-tag todo:a:"To Do:"
-tag throws
-tag see
-tag example:X
When the javadoc command parses the documentation comments, any
tag encountered that is neither a standard tag nor passed in
with the -tag or -taglet options is considered unknown, and a
warning is thrown.
The standard tags are initially stored internally in a list in
their default order. Whenever the -tag options are used, those
tags get appended to this list. Standard tags are moved from
their default position. Therefore, if a -tag option is omitted
for a standard tag, then it remains in its default position.
Avoiding conflicts: If you want to create your own namespace,
then you can use a dot-separated naming convention similar to
that used for packages: com.mycompany.todo. Oracle will continue
to create standard tags whose names do not contain dots. Any tag
you create will override the behavior of a tag by the same name
defined by Oracle. If you create a @todo tag or taglet, then it
always has the same behavior you define, even when Oracle later
creates a standard tag of the same name.
Annotations vs. Javadoc tags: In general, if the markup you want
to add is intended to affect or produce documentation, then it
should be a Javadoc tag. Otherwise, it should be an annotation.
See Custom Tags and Annotations in How to Write Doc Comments for
the Javadoc Tool at
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#annotations
You can also create more complex block tags or custom inline
tags with the -taglet option.
-taglet class
Specifies the class file that starts the taglet used in
generating the documentation for that tag. Use the fully
qualified name for the class value. This taglet also defines the
number of text arguments that the custom tag has. The taglet
accepts those arguments, processes them, and generates the
output. For extensive documentation with example taglets, see:
Taglet Overview at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/taglet/overview.html
Taglets are useful for block or inline tags. They can have any
number of arguments and implement custom behavior, such as
making text bold, formatting bullets, writing out the text to a
file, or starting other processes. Taglets can only determine
where a tag should appear and in what form. All other decisions
are made by the doclet. A taglet cannot do things such as remove
a class name from the list of included classes. However, it can
execute side effects, such as printing the tag's text to a file
or triggering another process. Use the -tagletpath option to
specify the path to the taglet. The following example inserts
the To Do taglet after Parameters and ahead of Throws in the
generated pages. Alternately, you can use the -taglet option in
place of its -tag option, but that might be difficult to read.
-taglet com.sun.tools.doclets.ToDoTaglet
-tagletpath /home/taglets
-tag return
-tag param
-tag todo
-tag throws
-tag see
-tagletpath tagletpathlist
Specifies the search paths for finding taglet class files. The
tagletpathlist can contain multiple paths by separating them
with a colon (:). The javadoc command searches all
subdirectories of the specified paths.
-docfilesubdirs
Enables deep copying of doc-files directories. Subdirectories
and all contents are recursively copied to the destination. For
example, the directory doc-files/example/images and all of its
contents would be copied. There is also an option to exclude
subdirectories.
-excludedocfilessubdir name1:name2
Excludes any doc-files subdirectories with the specified names.
This prevents the copying of SCCS and other source-code-control
subdirectories.
-noqualifier all | packagename1:packagename2...
Omits qualifying package names from class names in output. The
argument to the -noqualifier option is either all (all package
qualifiers are omitted) or a colon-separate list of packages,
with wild cards, to be removed as qualifiers. The package name
is removed from places where class or interface names appear.
See Process Source Files.
The following example omits all package qualifiers: -noqualifier
all.
The following example omits java.lang and java.io package
qualifiers: -noqualifier java.lang:java.io.
The following example omits package qualifiers starting with
java, and com.sun subpackages, but not javax: -noqualifier
java.*:com.sun.*.
Where a package qualifier would appear due to the previous
behavior, the name can be suitably shortened. See How a Name
Appears. This rule is in effect whether or not the -noqualifier
option is used.
-notimestamp
Suppresses the time stamp, which is hidden in an HTML comment in
the generated HTML near the top of each page. The -notimestamp
option is useful when you want to run the javadoc command on two
source bases and get the differences between diff them, because
it prevents time stamps from causing a diff (which would
otherwise be a diff on every page). The time stamp includes the
javadoc command release number, and currently appears similar to
this: <!-- Generated by javadoc (build 1.5.0_01) on Thu Apr 02
14:04:52 IST 2009 -->.
-nocomment
Suppresses the entire comment body, including the main
description and all tags, and generate only declarations. This
option lets you reuse source files that were originally intended
for a different purpose so that you can produce skeleton HTML
documentation at the early stages of a new project.
-sourcetab tablength
Specifies the number of spaces each tab uses in the source.
COMMAND-LINE ARGUMENT FILES
To shorten or simplify the javadoc command, you can specify one or more
files that contain arguments to the javadoc command (except -J
options). This enables you to create javadoc commands of any length on
any operating system.
An argument file can include javac options and source file names in any
combination. The arguments within a file can be space-separated or
newline-separated. If a file name contains embedded spaces, then put
the whole file name in double quotation marks.
File Names within an argument file are relative to the current
directory, not the location of the argument file. Wild cards (*) are
not allowed in these lists (such as for specifying *.java). Using the
at sign (@) to recursively interpret files is not supported. The -J
options are not supported because they are passed to the launcher,
which does not support argument files.
When you run the javadoc command, pass in the path and name of each
argument file with the @ leading character. When the javadoc command
encounters an argument beginning with the at sign (@), it expands the
contents of that file into the argument list.
Example 1 Single Argument File
You could use a single argument file named argfile to hold all javadoc
command arguments: javadoc @argfile. The argument file contains the
contents of both files, as shown in the next example.
Example 2 Two Argument Files
You can create two argument files: One for the javadoc command options
and the other for the package names or source file names. Notice the
following lists have no line-continuation characters.
Create a file named options that contains:
-d docs-filelist
-use
-splitindex
-windowtitle 'Java SE 7 API Specification'
-doctitle 'Java SE 7 API Specification'
-header '<b>Javatm SE 7</b>'
-bottom 'Copyright © 1993-2011 Oracle and/or its affiliates. All rights reserved.'
-group "Core Packages" "java.*"
-overview /java/pubs/ws/1.7.0/src/share/classes/overview-core.html
-sourcepath /java/pubs/ws/1.7.0/src/share/classes
Create a file named packages that contains:
com.mypackage1
com.mypackage2
com.mypackage3
Run the javadoc command as follows:
javadoc @options @packages
Example 3 Argument Files with Paths
The argument files can have paths, but any file names inside the files
are relative to the current working directory (not path1 or path2):
javadoc @path1/options @path2/packages
Example 4 Option Arguments
The following example saves an argument to a javadoc command option in
an argument file. The -bottom option is used because it can have a
lengthy argument. You could create a file named bottom to contain the
text argument:
<font size="-1">
<a href="http://bugreport.sun.com/bugreport/">Submit a bug or feature</a><br/>
Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved. <br/>
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.</font>
Run the javadoc command as follows:javadoc -bottom @bottom @packages.
You can also include the -bottom option at the start of the argument
file and run the javadoc command as follows: javadoc @bottom @packages.
RUNNING THE JAVADOC COMMAND
The release number of the javadoc command can be determined with the
javadoc -J-version option. The release number of the standard doclet
appears in the output stream. It can be turned off with the -quiet
option.
Use the public programmatic interface to call the javadoc command from
within programs written in the Java language. This interface is in
com.sun.tools.javadoc.Main (and the javadoc command is reentrant). For
more information, see The Standard Doclet at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/standard-
doclet.html#runningprogrammatically
The following instructions call the standard HTML doclet. To call a
custom doclet, use the -doclet and -docletpath options. See Doclet
Overview at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/doclet/overview.html
SIMPLE EXAMPLES
You can run the javadoc command on entire packages or individual source
files. Each package name has a corresponding directory name.
In the following examples, the source files are located at
/home/src/java/awt/*.java. The destination directory is /home/html.
Document One or More Packages
To document a package, the source files for that package must be
located in a directory that has the same name as the package.
If a package name has several identifiers (separated by dots, such as
java.awt.color), then each subsequent identifier must correspond to a
deeper subdirectory (such as java/awt/color).
You can split the source files for a single package among two such
directory trees located at different places, as long as -sourcepath
points to them both. For example, src1/java/awt/color and
src2/java/awt/color.
You can run the javadoc command either by changing directories (with
the cd command) or by using the -sourcepath option. The following
examples illustrate both alternatives.
Example 1 Recursive Run from One or More Packages
This example uses -sourcepath so the javadoc command can be run from
any directory and -subpackages (a new 1.4 option) for recursion. It
traverses the subpackages of the java directory excluding packages
rooted at java.net and java.lang. Notice this excludes java.lang.ref, a
subpackage of java.lang. To also traverse down other package trees,
append their names to the -subpackages argument, such as
java:javax:org.xml.sax.
javadoc -d /home/html -sourcepath /home/src -subpackages java -exclude
Example 2 Change to Root and Run Explicit Packages
Change to the parent directory of the fully qualified package. Then,
run the javadoc command with the names of one or more packages that you
want to document:
cd /home/src/
javadoc -d /home/html java.awt java.awt.event
To also traverse down other package trees, append their names to the
-subpackages argument, such as java:javax:org.xml.sax.
Example 3 Run from Any Directory on Explicit Packages in One Tree
In this case, it does not matter what the current directory is. Run the
javadoc command and use the -sourcepath option with the parent
directory of the top-level package. Provide the names of one or more
packages that you want to document:
javadoc -d /home/html -sourcepath /home/src java.awt java.awt.event
Example 4 Run from Any Directory on Explicit Packages in Multiple Trees
Run the javadoc command and use the -sourcepath option with a colon-
separated list of the paths to each tree's root. Provide the names of
one or more packages that you want to document. All source files for a
specified package do not need to be located under a single root
directory, but they must be found somewhere along the source path.
javadoc -d /home/html -sourcepath /home/src1:/home/src2 java.awt java.awt.event
The result is that all cases generate HTML-formatted documentation for
the public and protected classes and interfaces in packages java.awt
and java.awt.event and save the HTML files in the specified destination
directory. Because two or more packages are being generated, the
document has three HTML frames: one for the list of packages, another
for the list of classes, and the third for the main class pages.
Document One or More Classes
The second way to run the javadoc command is to pass one or more source
files. You can run javadoc either of the following two ways: by
changing directories (with the cd command) or by fully specifying the
path to the source files. Relative paths are relative to the current
directory. The -sourcepath option is ignored when passing source files.
You can use command-line wild cards, such as an asterisk (*), to
specify groups of classes.
Example 1 Change to the Source Directory
Change to the directory that holds the source files. Then run the
javadoc command with the names of one or more source files you want to
document.
This example generates HTML-formatted documentation for the classes
Button, Canvas, and classes that begin with Graphics. Because source
files rather than package names were passed in as arguments to the
javadoc command, the document has two frames: one for the list of
classes and the other for the main page.
cd /home/src/java/awt
javadoc -d /home/html Button.java Canvas.java Graphics*.java
Example 2 Change to the Root Directory of the Package
This is useful for documenting individual source files from different
subpackages off of the same root. Change to the package root directory,
and supply the source files with paths from the root.
cd /home/src/
javadoc -d /home/html java/awt/Button.java java/applet/Applet.java
Example 3 Document Files from Any Directory
In this case, it does not matter what the current directory is. Run the
javadoc command with the absolute path (or path relative to the current
directory) to the source files you want to document.
javadoc -d /home/html /home/src/java/awt/Button.java
/home/src/java/awt/Graphics*.java
Document Packages and Classes
You can document entire packages and individual classes at the same
time. Here is an example that mixes two of the previous examples. You
can use the -sourcepath option for the path to the packages but not for
the path to the individual classes.
javadoc -d /home/html -sourcepath /home/src java.awt
/home/src/java/applet/Applet.java
REAL-WORLD EXAMPLES
The following command-line and makefile versions of the javadoc command
run on the Java platform APIs. It uses 180 MB of memory to generate the
documentation for the 1500 (approximately) public and protected classes
in the Java SE 1.2. Both examples use absolute paths in the option
arguments, so that the same javadoc command can be run from any
directory.
Command-Line Example
The following command might be too long for some shells. You can use a
command-line argument file (or write a shell script) to overcome this
limitation.
In the example, packages is the name of a file that contains the
packages to process, such as java.appletjava.lang. None of the options
should contain any newline characters between the single quotation
marks. For example, if you copy and paste this example, then delete the
newline characters from the -bottom option.
javadoc -sourcepath /java/jdk/src/share/classes \
-overview /java/jdk/src/share/classes/overview.html \
-d /java/jdk/build/api \
-use \
-splitIndex \
-windowtitle 'Java Platform, Standard Edition 7 API Specification' \
-doctitle 'Java Platform, Standard Edition 7 API Specification' \
-header '<b>Javatm SE 7</b>' \
-bottom '<font size="-1">
<a href="http://bugreport.sun.com/bugreport/">Submit a bug or feature</a><br/>
Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.<br/>
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.</font>' \
-group "Core Packages" "java.*:com.sun.java.*:org.omg.*" \
-group "Extension Packages" "javax.*" \
-J-Xmx180m \
@packages
Programmatic Interface
The Javadoc Access API enables the user to invoke the Javadoc tool
directly from a Java application without executing a new process.
For example, the following statements are equivalent to the command
javadoc -d /home/html -sourcepath /home/src -subpackages java -exclude
java.net:java.lang com.example:
import javax.tools.DocumentationTool;
import javax.tools.ToolProvider;
public class JavaAccessSample{
public static void main(String[] args){
DocumentationTool javadoc = ToolProvider.getSystemDocumentationTool();
int rc = javadoc.run( null, null, null,
"-d", "/home/html",
"-sourcepath", "home/src",
"-subpackages", "java",
"-exclude", "java.net:java.lang",
"com.example");
}
}
The first three arguments of the run method specify input, standard
output, and standard error streams. Null is the default value for
System.in, System.out, and System.err, respectively.
THE MAKEFILE EXAMPLE
This is an example of a GNU makefile. Single quotation marks surround
makefile arguments. For an example of a Windows makefile, see the
makefiles section of the Javadoc FAQ at
http://www.oracle.com/technetwork/java/javase/documentation/index-137483.html#makefiles
javadoc -sourcepath $(SRCDIR) \ /* Sets path for source files */
-overview $(SRCDIR)/overview.html \ /* Sets file for overview text */
-d /java/jdk/build/api \ /* Sets destination directory */
-use \ /* Adds "Use" files */
-splitIndex \ /* Splits index A-Z */
-windowtitle $(WINDOWTITLE) \ /* Adds a window title */
-doctitle $(DOCTITLE) \ /* Adds a doc title */
-header $(HEADER) \ /* Adds running header text */
-bottom $(BOTTOM) \ /* Adds text at bottom */
-group $(GROUPCORE) \ /* 1st subhead on overview page */
-group $(GROUPEXT) \ /* 2nd subhead on overview page */
-J-Xmx180m \ /* Sets memory to 180MB */
java.lang java.lang.reflect \ /* Sets packages to document */
java.util java.io java.net \
java.applet
WINDOWTITLE = 'Javatm SE 7 API Specification'
DOCTITLE = 'Javatm Platform Standard Edition 7 API Specification'
HEADER = '<b>Javatm SE 7</font>'
BOTTOM = '<font size="-1">
<a href="http://bugreport.sun.com/bugreport/">Submit a bug or feature</a><br/>
Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.<br/>
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.</font>'
GROUPCORE = '"Core Packages" "java.*:com.sun.java.*:org.omg.*"'
GROUPEXT = '"Extension Packages" "javax.*"'
SRCDIR = '/java/jdk/1.7.0/src/share/classes'
NOTES
o If you omit the -windowtitle option, then the javadoc command copies
the document title to the window title. The -windowtitle option text
is similar to the the -doctitle option, but without HTML tags to
prevent those tags from appearing as raw text in the window title.
o If you omit the -footer option, then the javadoc command copies the
header text to the footer.
o Other important options you might want to use, but were not needed in
the previous example, are the -classpath and -link options.
GENERAL TROUBLESHOOTING
o The javadoc command reads only files that contain valid class names.
If the javadoc command is not correctly reading the contents of a
file, then verify that the class names are valid. See Process Source
Files.
o See the Javadoc FAQ for information about common bugs and for
troubleshooting tips at
http://www.oracle.com/technetwork/java/javase/documentation/index-137483.html
ERRORS AND WARNINGS
Error and warning messages contain the file name and line number to the
declaration line rather than to the particular line in the
documentation comment.
For example, this message error: cannot read: Class1.java means that
the javadoc command is trying to load Class1.java in the current
directory. The class name is shown with its path (absolute or
relative).
ENVIRONMENT
CLASSPATH
CLASSPATH is the environment variable that provides the path
that the javadoc command uses to find user class files. This
environment variable is overridden by the -classpath option.
Separate directories with a semicolon for Windows or a colon for
Oracle Solaris.
Windows example: .;C:\classes;C:\home\java\classes
Oracle Solaris example: .:/home/classes:/usr/local/java/classes.
SEE ALSO
o javac(1)
o java(1)
o jdb(1)
o javap(1)
RELATED DOCUMENTS
o Javadoc Technology at
http://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/index.html
o How Classes Are Found
http://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html
o How to Write Doc Comments for the Javadoc Tool
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html
o URL Memo, Uniform Resource Locators
http://www.ietf.org/rfc/rfc1738.txt
o HTML standard, HTML Document Representation (4197265 and 4137321)
http://www.w3.org/TR/REC-html40/charset.html#h-5.2.2
JDK 8 03 March 2015 javadoc(1)