javadoc(1) javadoc(1)
NAME
javadoc - Java API documentation generator
SYNOPSIS
javadoc [ options ] [ packagenames ] [ sourcefilenames ]
[ -subpackages [pkg1:pkg2:...] ] [ @argfiles ]
ARGUMENTS
Arguments can be in any order.
options
Command-line options, as specified in this document. To see a
typical use of javadoc options, see Real World Example.
packagenames
A series of names of packages, separated by spaces, such as
java.lang java.lang.reflect java.awt. You must separately spec-
ify each package you want to document. javadoc uses -sourcepath
to look for these package names. javadoc does not recursively
traverse subpackages. Wildcards such as asterisks (**) are not
allowed. See EXAMPLES, Documenting One or More Packages.
sourcefiles
A series of source file names, separated by spaces, each of
which can begin with a path and contain a wildcard such as an
asterisk (**). javadoc will process every file whose name ends
with .java, and whose name, when stripped of that suffix, is
actually a legal class name (see Identifiers). Therefore, you
can name files with dashes (such as X-Buffer), or other illegal
characters, to prevent them from being documented. This is use-
ful for test files and files generated from templates. The path
that precedes the source file name determines where javadoc will
look for it. (javadoc does not use -sourcepath to look for
these source file names.) For example, passing in Button.java
is identical to ./Button.java. An example source file name with
a full path is /home/src/java/awt/Graphics**.java. See EXAMPLES,
Documenting One or More Classes. You can also mix packagenames
and sourcefiles, as in EXAMPLES, Documenting Both Packages and
Classes.
-subpackages pkg1:pkg2:...
Generates documentation from source files in the specified pack-
ages and recursively in their subpackages. An alternative to
supplying packagenames or sourcefilenames.
@argfiles
One or more files that contain a list of javadoc options, packa-
genames and sourcefiles in any order. Wildcards (**) and -J
options are not allowed in these files.
DESCRIPTION
javadoc parses the declarations and documentation comments in a set of
Java source files and produces a corresponding set of HTML pages
describing (by default) the public and protected classes, nested
classes (but not anonymous inner classes), interfaces, constructors,
methods, and fields.
You can run javadoc on entire packages, individual source files, or
both. In the first case, you pass in as an argument to javadoc a
series of package names. In the second case, you pass in a series of
source (.java) file names. EXAMPLES are given at the end of this docu-
ment.
Note: When you pass in package names to javadoc, it currently processes
all .java classes in the specified package directories, even if the
.java files are code examples or other classes that are not actually
members of the specified packages. It does not parse each .java file
for a package declaration; this parsing may be added in a future
release.
During a run, javadoc automatically adds cross-reference links to pack-
age, class and member names that are being documented as part of that
run. Links appear in several places:
]o Declarations (return types, argument types, field types)
]o "See Also" sections generated from @@see tags
]o In-line text generated from {@@link} tags
]o Exception names generated from @@throws tags
]o Specified by links to members in interfaces and Overrides links to
members in classes
]o Summary tables listing packages, classes and members
]o Package and class inheritance trees
]o The index
You can add hyperlinks to existing text for classes not included on the
command line (but generated separately) by way of the -link and
-linkoffline options.
javadoc produces one complete document each time it is run; it cannot
do incremental builds -- that is, it cannot modify or directly incorpo-
rate results from previous runs of javadoc tool. However, it can link
to results from previous runs, as just mentioned.
As implemented, javadoc requires and relies on the java compiler to do
its job. javadoc calls part of javac to compile the declarations,
ignoring the member implementation. It builds a rich internal repre-
sentation of the classes, including the class hierarchy and "use" rela-
tionships, then generates the HTML from that. javadoc also picks up
user-supplied documentation from documentation comments in the source
code.
In fact, javadoc will run on .java source files that are pure stub
files with no method bodies. This means you can write documentation
comments and run javadoc in the earliest stages of design while creat-
ing the API, before writing the 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, javadoc will document
default constructors (section 8.6.7 of Java Language Specification)
that are present in the .class files but not in the source code.
In many cases, javadoc allows you to generate documentation for source
files whose code is incomplete or erroneous. This is a benefit that
enables you to generate documentation before all debugging and trou-
bleshooting is done. For example, according to the Java Language Speci-
fication, a class that contains an abstract method should itself be
declared abstract. javadoc does not check for this, and would proceed
without a warning, whereas the javac compiler stops on this error.
javadoc does do some primitive checking of doc comments. Use the Doc-
Check doclet to check the doc comments more thoroughly.
When javadoc builds its internal structure for the documentation, it
loads all referenced classes. Because of this, javadoc must be able to
find all referenced classes, whether bootstrap classes, extensions, or
user classes. For more about this, see How Classes Are Found. Gener-
ally speaking, classes you create must either be loaded as an extension
or in the class path of javadoc.
JAVADOC DOCLETS
You can customize the content and format of the output of javadoc by
using doclets. javadoc has a default "built-in" doclet, called the
standard doclet, that generates HTML-formatted API documentation. You
can modify or subclass the standard doclet, or write your own doclet to
generate HTML, XML, MIF, RTF or whatever output format you prefer.
Information about doclets and their use is at the following locations:
]o javadoc Doclets
]o The -doclet command-line option
When a custom doclet is not specified with the -doclet command line
option, javadoc uses the default standard doclet. The javadoc tool has
several command line options that are available regardless of which
doclet is being used. The standard doclet adds a supplementary set of
command line options. Both sets of options are described below in the
options section.
RELATED DOCUMENTATION AND DOCLETS
]o Javadoc Enhancements for details about improvements added in Javadoc
1.4.
]o Javadoc FAQ for answers to common questions, information about
Javadoc-related tools, and workarounds for bugs.
]o How to Write Doc Comments for Javadoc for more information about Sun
conventions for writing documentation comments.
]o Requirements for Writing API Specifications - Standard requirements
used when writing the Java 2 Platform Specification. It can be useful
whether you are writing API specifications in source file documenta-
tion comments or in other formats. It covers requirements for pack-
ages, classes, interfaces, fields and methods to satisfy testable
assertions.
]o Documentation Comment Specification - The original specification on
documentation comments, Chapter 18, Documentation Comments, in the
Java Language Specification, First Edition, by James Gosling, Bill
Joy, and Guy Steele. (This chapter was removed from the second edi-
tion.)
]o DocCheck Doclet - Checks doc comments in source files and generates a
report listing the errors and irregularities it finds. It is part of
the Sun Doc Check Utilities.
]o MIF Doclet - Can automate the generation of API documentation in MIF,
FrameMaker and PDF formats. MIF is Adobe FrameMaker's interchange
format.
TERMINOLOGY
A few terms have specific meanings within the context of javadoc:
generated document
The document generated by the javadoc tool from the doc comments
in Java source code. The default generated document is in HTML
and is created by the standard doclet.
name A name in the Java Language, namely the name of a package,
class, interface, field, constructor, or method. A name can be
partially-qualified, such as equals(Object), or fully-qualified,
such as java.lang.String.equals(java.lang.Object).
documented classes
The classes and interfaces for which full documentation is gen-
erated during a javadoc run. To be documented, the source files
must be available, and either their source filenames or package
names must be passed into the javadoc command. We also refer to
these as the classes included in the javadoc run, or the
included classes.
excluded classes
Classes and interface whose source filenames or package names
are not passed into the javadoc command.
referenced classes
The classes and interfaces that are explicitly referred to in
the definition (implementation) or doc comments of the docu-
mented classes and interfaces. Examples of references include
return type, parameter type, cast type, extended class, imple-
mented interface, imported classes, classes used in method bod-
ies, and @@see, {@@link}, {@@linkplain}, and {@@inheritDoc} tags.
(Notice that this definition has changed since 1.3.) When
javadoc is run, it loads into memory all of the referenced
classes in the bootclasspath and classpath of javadoc. (javadoc
prints a "Class not found" warning for referenced classes not
found.) javadoc can derive enough information from the .class
files to determine their existence and the fully qualified names
of their members.
external referenced classes
The referenced classes whose documentation is not being gener-
ated during a javadoc run. In other words, these classes are not
passed into javadoc on the command line. Links in the generated
documentation to those classes are said to be external refer-
ences or external links. For example, if you run javadoc on only
the java.awt package, then any class in java.lang, such as
Object, is an external referenced class. External referenced
classes can be linked to using the -link and -linkoffline
options. An important property of an external referenced class
is that its source comments are normally not available to the
javadoc run. In this case, these comments cannot be inherited.
SOURCE FILES
javadoc generates output originating from four different types of
"source" files: Java language source files for classes (.java), package
comment files, overview comment files, and miscellaneous unprocessed
files.
CLAS SOURCE CODE FILES
Each class or interface and its members can have their own documenta-
tion comments, contained in a .java file. For more details about these
doc commments, see Documentation Comments.
PACKAGE COMENT FILES
Each package can have its own documentation comment, contained in its
own "source" file, that javadoc will merge into the package summary
page that it generates. You typically include in this comment any doc-
umentation that applies to the entire package.
To create a package comment file, you must name it package.html and
place it in the package directory in the source tree along with the
.java files. javadoc will automatically look for this filename in this
location. Notice that the filename is identical for all packages. For
explicit details, see the example of package.html.
The content of the package comment file is one big documentation com-
ment, written in HTML, like all other comments, with one exception: the
documentation comment should not include the comment separators /** and
*/ or leading asterisks. When writing the comment, you should make the
first sentence a summary about the package, and not put a title or any
other text between <> and the first sentence. You can include
package tags. As with any documentation comment, all tags except
{@@link} must appear after the description. If you add a @@see tag in a
package comment file, it must have a fully qualified name.
When javadoc runs, it automatically looks for this file; if found,
javadoc does the following:
]o Copies all content between <> and <> tags for processing.
]o Processes any package tags that are present.
]o Inserts the processed text at the bottom of the package summary page
it generates, as shown in Package Summary.
]o Copies the first sentence of the package comment to the top of the
package summary page. It also adds the package name and this first
sentence to the list of packages on the overview page, as shown in
Overview Summary. The end-of-sentence is determined by the same
rules used for the end of the first sentence of class and member
descriptions.
OVERVIEW COMENT FILE
Each application or set of packages that you are documenting can have
its own overview documentation comment, kept in its own "source" file,
that javadoc merges into the overview page that it generates. You typ-
ically include in this comment any documentation that applies to the
entire application or set of packages.
To create an overview comment file, you can name the file anything you
want, typically overview.html, and place it anywhere, typically at the
top level of the source tree. Notice that you can have multiple over-
view comment files for the same set of source files, in case you want
to run javadoc multiple times on different sets of packages. For exam-
ple, if the source files for the java.applet package are contained in
/home/user/src/java/applet directory, you could create an overview com-
ment file at /home/user/src/overview.html.
The content of the overview comment file is one big documentation com-
ment, written in HTML, like the package comment file described previ-
ously. See that description for details. To reiterate, when writing
the comment, you should make the first sentence a summary about the
application or set of packages, and not put a title or any other text
between <> and the first sentence. You can include overview tags;
as with any documentation comment, all tags except {@@link} must appear
after the description. If you add a @@see tag, it must have a fully-
qualified name.
When you run javadoc, you specify the overview comment file name with
the -overview option. The file is then processed, similar to that of a
package comment file:
]o Copies all content between <> and <> tags for processing.
]o Processes any overview tags that are present.
]o Inserts the processed text at the bottom of the overview page it gen-
erates, as shown in Overview Summary.
]o Copies the first sentence of the overview comment to the top of the
overview summary page.
MISCELANEOUS UNPROCESED FILES
You can also include in your source any miscellaneous files that you
want javadoc to copy to the destination directory. These typically
include graphic files (for example, Java source (.java) and class
(.class) files) and self-standing HTML files whose content would over-
whelm the documentation comment of a normal Java source file.
To include unprocessed files, put them in a directory called doc-files,
which can be a subdirectory of any package directory. You can have one
such subdirectory for each package. You might include images, example
code, source files, .class files, applets, and HTML files. For exam-
ple, if you want to include the image of a button button.gif in the
java.awt.Button class documentation, you place that file in the
/home/user/src/java/awt/doc-files/ directory.
All links to these unprocessed files must be hard-coded, because
javadoc does not look at the files -- it simply copies the directory
and all its contents to the destination. For example, the link in the
Button.java doc comment might look like this:
/****
** This button looks like this::
** <![](=""doc-files/Button.gif"") >
**/
GENERATED FILES
By default, javadoc uses a standard doclet that generates HTML-format-
ted documentation. This doclet generates the following kinds of files
(where each HTML "page" corresponds to a separate file). Notice that
javadoc generates files with two types of names: those named after
classes/interfaces, and those that are not (such as package-sum-
mary.html). Files in the latter group contain hyphens to prevent file
name conflicts with those in the former group.
BASIC CONTENT PAGES
]o One class or interface page (classname.html) for each class or inter-
face it is documenting.
]o One package page (package-summary.html) for each package it is docu-
menting. javadoc includes any HTML text provided in a file named
package.html in the package directory of the source tree.
]o One overview page (overview-summary.html) for the entire set of pack-
ages. This is the front page of the generated document. javadoc
includes any HTML text provided in a file specified with the -over-
view option. Notice that this file is created only if you pass into
javadoc two or more package names. For further explanation, see HTML
Frames.
CROS-REFERENCE PAGES
]o One class hierarchy page for the entire set of packages (overview-
tree.html). To view this, click on "Overview" in the navigation bar,
then click on "Tree".
]o One class hierarchy page for each package (package-tree.html). To
view this, go to a particular package, class or interface page; click
"Tree" to display the hierarchy for that package.
]o One "use" page for each package (package-use.html) and a separate one
for each class and interface (class-use/classname.html). This page
describes what packages, classes, methods, constructors, and fields
use any part of the given class, interface, or package. 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. You can access this page by first going
to the package, class, or interface, then clicking on the "Use" link
in the navigation bar.
]o A deprecated API page (deprecated-list.html) listing all deprecated
names. (A deprecated name is not recommended for use, generally due
to improvements, and a replacement name is usually given. Deprecated
APIs might 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) for information about
serializable and externalizable classes. Each such class has a
description of its serialization fields and methods. This information
is of interest to re-implementors, not to developers using the API.
While there is no link in the navigation bar, you can get to this
information by going to any serialized class and clicking "Serialized
Form" in the "See also" section of the class description. The stan-
dard doclet automatically generates a serialized form page: any class
(public or non-public) that implements Serializable is included,
along with readObject and writeObject methods, the fields that are
serialized, and the doc comments from the @@serial, @@serialField, and
@@serialData tags. Public serializable classes can be excluded by
marking them (or their package) with @@serial exclude, and pack-
age-private serializable classes can be included by marking them (or
their package) with @@serial include. As of 1.4, you can generate the
complete serialized form for public and private classes by running
javadoc without specifying the -private option.
]o An index (index-**.html) of all class, interface, constructor, field
and method names, alphabetically arranged. This 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).
SUPORT FILES
]o A help page (help-doc.html) that describes the navigation bar and the
above pages. You can provide your own custom help file to override
the default using -helpfile.
]o One index.html file that creates the HTML frames for display. This
is the file you load to display the front page with frames. This
file itself contains no text content.
]o Several frame files (**-frame.html) containing lists of packages,
classes and interfaces, used when HTML frames are being displayed.
]o A package list file (package-list), used by the -link and -linkof-
fline options. This is a text file, not HTML, and is not reachable
through any links.
]o A style sheet file (stylesheet.css) that controls a limited amount of
color, font family, font size, font style, and positioning on the
generated pages.
]o A doc-files directory that holds any image, example, source code, or
other files that you want copied to the destination directory. These
files are not processed by javadoc in any manner, that is, any
javadoc tags in them will be ignored. This directory is not gener-
ated unless it exists in the source tree.
HTML FRAMES
javadoc generates either two or three HTML frames, as shown in the fig-
ure below. When you pass source files (*.java) or a single package
name as arguments into the javadoc command, it creates only one frame
(C) in the left-hand column, that is, the list of classes. When you
pass into javadoc two or more package names, it creates a third frame
(P) listing all packages, as well as an overview page (Detail). This
overview page has the file name, overview-summary.html. Thus, this
file is created only if you pass in two or more package names. You can
bypass frames by clicking on the "No Frames" link or entering at over-
view-summary.html.
If you are unfamiliar with HTML frames, you should be aware that frames
can have focus for printing and scrolling. To give a frame focus,
click on it. Then, on many browsers the arrow keys and page keys will
scroll that frame, and the print menu command will print it.
------------ ------------
C Detail P Detail
-
C
------------ ------------
javadoc **.java javadoc java.lang java.awt
Load one of the following two files as the starting page depending on
whether you want HTML frames or not:
]o index.html (for frames)
]o overview-summary.html (for no frames)
GENERATED FILE STRUCTURE
The generated class and interface files are organized in the same
directory hierarchy as Java source files and class files. This struc-
ture is one directory per subpackage.
For example, the document generated for the class java.applet.Applet
would be located at java/applet/Applet.html. The file structure for
the java.applet package follows, given 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.
NOTE: Directories are shown in bold. The asterisks (*) indicate the
files and directories that are omitted when the arguments to javadoc
are source file names (*.java) rather than package names. Also, when
arguments are source file names, package-list is created but is empty.
The doc-files directory is not created in the destination unless it
exists in the source tree.
apidocs Top directory
index.html Initial page that sets up HTML frames
* overview-summary.html Lists all packages with first sentence
summaries
overview-tree.html Lists class hierarchy for all packages
deprecated-list.html Lists deprecated API for all packages
serialized-form.html Lists serialized form for all packages
* overview-frame.html Lists all packages, used in upper-left
frame
allclasses-frame.html Lists all classes for all packages,
used in lower-left frame
help-doc.html Lists user help for how these pages are
organized
index-all.html Default index created without -splitindex
index-files Directory created with -splitindex
index-.html Index files created with -splitindex
package-list Lists package names, used only for
resolving external refs
stylesheet.css HTML style sheet for defining fonts,
colors and positions
java Package directory
applet Subpackage directory
Applet.html Page for Applet class
AppletContext.html Page for AppletContext interface
AppletStub.html Page for AppletStub interface
AudioClip.html Page for AudioClip interface
* package-summary.html Lists classes with first sentence
summaries for this package
* package-frame.html Lists classes in this package, used in
lower left-hand frame
* package-tree.html Lists class hierarchy for this package
package-use Lists where this package is used
doc-files Directory holding image and example files
class-use Directory holding pages API is used
Applet.html Page for uses of Applet class
AppletContext.html Page for uses of AppletContext interface
AppletStub.html Page for uses of AppletStub interface
AudioClip.html Page for uses of AudioClip
src-html Source code directory
java Package directory
applet Subpackage directory
Applet.html Page for Applet source code
AppletContext.html Page for AppletContext source code
AppletStub.html Page for AppletStub source code
AudioClip.html Page for AudioClip source code
GENERATED API DECLARATIONS
The Javadoc tool generates a declaration at the start of each class,
interface, field, constructor, and method description. This declaration
is the declaration for that API item. For example, the declaration for
the Boolean class is:
public final class Boolean
extends Object
implements Serializable
and the declaration for the Boolean.valueOfmethod is:
public static Boolean valueOf(String s)
The Javadoc tool can include the modifiers public, protected, private,
abstract, final, static, transient, and volatile, but not synchronized
or native. These last two 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 comment description, as in "a single
Enumeration cannot be used by multiple threads concurrently". The docu-
ment should not describe how to achieve these semantics. As another
example, while Hashtable should be thread-safe, there's no reason to
specify that we achieve this by synchronizing all of its exported meth-
ods. We should reserve the right to synchronize internally at the
bucket level, thus offering higher concurrency.
DOCUMENTATION COMENTS
The original "Documentation Comment Specification" can be found under
related documentation.
Commenting the Source Code
You can include documentation comments ("doc comments") in the source
code, ahead of declarations for any class, interface, method, construc-
tor, or field. You can also create doc comments for each package and
another one for the overview, though their syntax is slightly differ-
ent. Doc comments are also known as Javadoc comments. A doc comment
consists of the characters between the characters /**** that begin the
comment and the characters **/ that end it. Leading asterisks are
allowed on each line and are described further below. The text in a
comment can continue onto multiple lines.
/****
** This is the typical format of a simple documentation comment.
**/
To save space you can put a comment on one line:
/**** This comment takes up only one line. **/
Documentation comments are recognized only when placed immediately
before class, interface, constructor, method, or field declarations
(see the class example, method example, and field example). Documenta-
tion comments placed in the body of a method are ignored. Only one
documentation comment per declaration statement is recognized by
javadoc.
A common mistake is to put an import statement between the class com-
ment and the class declaration. Avoid this, as javadoc will ignore the
class comment.
/****
** This is the class comment for the class Whatever.
**/
import com.sun;; // MISTAKE - Important not to put statements here
public class Whatever {{
}}
A comment is a description followed by a tag section. The description
begins after the starting delimiter /**** and continues until the tag
section. The tag section starts with the first character @@ that begins
a line (ignoring leading asterisks, white space, and separator /**).
It is possible to have a comment with only tags and no description.
The description cannot continue after the tag section begins. The argu-
ment to a tag can span multiple lines. There can be any number of tags
-- some types of tags can be repeated while others cannot. This @@see
starts the tag section:
/****
** This is a doc comment.
** @@see java.lang.Object
**/
Standalone and In-line Tags
A tag is a special keyword within a doc comment that javadoc can
process. javadoc has standalone tags, which appear as @@tag, and in-line
tags, which appear within braces, as {@@tag}. To be interpreted, a
standalone tag must appear at the beginning of a line, ignoring leading
asterisks, white space, and 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, use the HTML entity &&##0064;;. Each standalone
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 doc com-
ment. This associated text can span multiple lines. An in-line tag is
allowed and interpreted anywhere that text is allowed. The following
example contains the standalone tag @@deprecated and in-line tag
{@@link}.
/****
** @@deprecated As of JDK 1.1,, replaced \\
by {{@@link ##setBounds(int,,int,,int,,int)}}
**/
Comments are written in HTML
The text must be written in HTML so that comments can use HTML entities
and HTML tags. You can use whichever version of HTML your browser sup-
ports; we have written the standard doclet to generate HTML 3.2-compli-
ant code elsewhere (outside of the documentation comments) with the
inclusion of cascading style sheets and frames. (We preface each gen-
erated file with "HTML 4.0" because of the frame sets.)
For example, entities for the less-than (<) and greater-than (>) sym-
bols should be written &<; and &>;. Likewise, the ampersand (&)
should be written &&;. The bold HTML tag is shown in the follow-
ing example:
/****
** This is a <>doc<> comment.
** @@see java.lang.Object
**/
Leading Asterisks
When javadoc parses a doc comment, leading asterisk (*) characters on
each line are discarded. Blanks and tabs preceding the initial asterisk
(*) characters are also discarded. Starting with 1.4, if you omit the
leading asterisk on a line, the leading white space is no longer
removed. This enables you to paste code examples directly into a doc
comment inside a tag, and its indentation will be honored. Spaces
are generally interpreted by browsers more uniformly than tabs. Inden-
tation is relative to the left margin (rather than the separator /** or
tag).
First Sentence
The first sentence of each doc comment should be a summary sentence,
containing 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 standalone tag. javadoc copies
this first sentence to the member summary at the top of the HTML page.
See -breakiterator for a description of how we are planning in a future
release to change the way the sentence break is determined.
Declaration With Multiple Fields
Java allows declaring multiple fields in a single statement, but this
statement can have only one documentation comment, which is copied for
all fields. Therefore, if you want individual documentation comments
for each field, you must declare each field in a separate statement.
For example, the following documentation comment does not make sense
when 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
javadoc generates the following documentation from the above 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 Header Tags Carefully
When writing documentation comments for members, it is best not to use
HTML heading tags such as <> and <>, because javadoc creates an
entire structured document and these structural tags can interfere with
the formatting of the generated document. However, it is fine to use
these headings in class and package comments to provide your own struc-
ture.
Automatic Re-use of Method Comments
The Javadoc tool has the ability to automatically reuse or "inherit"
method comments in classes an interfaces. When a description, or
@@return, @@param, @@see or @@throws tag is missing from a method comment,
javadoc instead copies the corresponding description or tag comment
from the method it overrides or implements (if any), according to the
algorithm below.
More specifically, when a @@param tag for a particular parameter is
missing, then the comment for that parameter is copied. When a @@throws
tag for a particular exception is missing, the @@throws tag is copied
only if that exception is declared.
This behavior contrasts with version 1.3 and earlier, where the pres-
ence of any description or tag would prevent all comments from being
inherited.
Also of interest, if the inline tag {@@inheritDoc} is present in a
description or any tag, the corresponding description or tag is copied
at that spot.
The overridden method must be a member of a documented class, and not
an external referenced class for the doc comment to actually be avail-
able to copy.
Inheriting of comments occurs in three cases:
]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, for method overrides, the Javadoc tool gener-
ates a subheading "Overrides" in the documentation for the overriding
method, with a link to the method it is overriding.
In the third case,when a method in a given class implements a method in
an interface, the Javadoc tool generates a subheading "Specified by" in
the documentation for the overriding method, with a link to the method
it is implementing.
Algorithm for Inheriting Method Descriptions
If a method does not have a doc comment, javadoc searches for an appli-
cable comment using the following algorithm, which is designed to find
the most specific applicable doc comment, giving preference to inter-
faces 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 doc comment found for this method.
2. If step 1 failed to find a doc comment, recursively apply this
entire algorithm to each directly implemented (or extended) inter-
face, in the same order they were examined in step 1.
3. If step 2 failed to find a doc comment and this is a class other
than Object (not an interface):
3a. If the superclass has a doc comment for this method, use it.
3b. If step 3a failed to find a doc comment, recursively apply this
entire algorithm to the superclass.
JAVADOC TAGS
javadoc parses special tags when they are embedded within a Javadoc
comment. These doc tags enable you to autogenerate a complete, well-
formatted API from your source code. The tags start with an "at" sign
(@@) and are case-sensitive; that is, they must be typed with the upper-
case 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 normal text. By convention, tags with the same name are
grouped together. For example, put all @@see tags together.
Tags come in two types:
]o Standalone tags - Can be placed only in the tag section that follows
the description. These tags are not set off with curly braces: @@tag.
]o Inline tags - Can be placed anywhere in the comment description or in
the comments for standalone tags. Inline tags are set off with curly
braces: {@@tag}.
For information about tags might be introduced in future releases, see
Proposed Tags.
The current tags are:
]--------------]-------------]
Tag Introduced
in JDK
]--------------]-------------]
@author 1.0
{@docRoot} 1.3
@deprecated 1.0
@exception 1.0
{@inheritDoc} 1.4
{@link} 1.2
{@linkplain} 1.4
@param 1.0
@return 1.0
@see 1.0
@serial 1.2
@serialData 1.2
@serialField 1.2
@since 1.1
@throws 1.2
{@value} 1.4
@version 1.0
]--------------]-------------]
For custom tags, see the -tag option.
@@author name-text
Adds an "Author" entry with the specified name-text to the gen-
erated docs when the -author option is used. A doc comment can
contain multiple @@author tags. You can specify one name per
@@author tag or multiple names per tag. In the former case,
javadoc inserts a comma (,,) and space between names. In the
latter case, the entire text is copied to the generated document
without being parsed. Therefore, use multiple names per line if
you want a localized name separator other than a comma.
@@deprecated deprecated-text
Adds a comment indicating that this API should no longer be used
(even though it might continue to work). javadoc moves the dep-
recated-text ahead of the description, placing it in italics and
preceding it with a bold warning: "Deprecated".
The first sentence of deprecated-text should at least tell the
user when the API was deprecated and what to use as a replace-
ment. javadoc copies just the first sentence to the summary
section and index. Subsequent sentences can also explain why it
has been deprecated. You should include a {@@link} tag (for
javadoc 1.2 or later) that points to the replacement API:
]o For javadoc 1.2 and later, use a {@@link} tag. This creates the
link in-line, where you want it. For example:
/****
** @@deprecated As of JDK 1.1,, replaced by
** {{@@link ##setBounds(int,,int,,int,,int)}}
**/
]o For javadoc 1.1, the standard format is to create a @@see tag
(which cannot be in-line) for each @@deprecated tag.
For more about deprecation, see the @@deprecated tag.
{{@@docRoot}}
Represents the relative path to the generated document's (desti-
nation) root directory from any generated page. It 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 doc comment:
1. On the command line, where the header/footer/bottom are
defined:
javadoc -bottom ''<>Copy-
right<>''
2. In a doc comment:
/****
** See the <>Copyright<>.
**/
The reason this tag is needed is because the generated docs are
in hierarchical directories, as deep as the number of subpack-
ages. This expression:
<>
would resolve to:
<> ... for
java/lang/Object.java
and
<> ... for
java/lang/ref/Reference.java
@@exception class-name description
The @@exception tag is a synonym for @@throws.
{@@inheritDoc}
Inherits documentation from the nearest superclass into the cur-
rent doc comment. This allows comments to be abstracted up the
inheritance tree, and enables developers to write around the
copied text. Also see inheriting comments.
This tag can be placed in two positions:
]o In the comment body (before the first standalone tag), where
it will copy the entire comment body from its superclass.
]o In the text argument of a standalone tag, where it will copy
the text of the tag from its superclass.
{@@link package.class#member label}
Inserts an in-line link with visible text label that points to
the documentation for the specified package, class or member
name of a referenced class.
This tag is very simliar to @@see -- both require the same refer-
ences and accept exactly the same syntax for package.class#mem-
ber and label. The main difference is that {@@link} generates an
in-line link rather than placing the link in the "See Also" sec-
tion. Also, the {@@link} tag begins and ends with curly braces to
separate it from the rest of the in-line text. If you need to
use "}" inside the label, use the HTML entity notation &&##125;;.
There is no limit to the number of {@@link} tags allowed in a
sentence. You can use this tag in the description part of a
documentation comment or in the text portion of any tag (such as
@@deprecated, @@return, or @@param).
For example, here is a comment that refers to the getComponen-
tAt(int,, int) method:
Use the {{@@link ##getComponentAt(int,, int) getComponentAt}} method.
From this, the standard doclet would generate the following HTML
(assuming it refers to another class in the same package):
Use the
<>\\
getComponentAt<>method.
which appears on the web page as:
Use the getComponentAt method.
{@@linkplain package.class#member label}
Identical to {{@@link}}, except the link's label is displayed in
plain text than code font. Useful when the label is plain text.
Example:
Refer to {{@@linkplain add() the overridden method}}.
This would display as:
Refer to the overridden method.
@@param parameter-name description
Adds a parameter to the "Parameters" section. The description
can continue on the next line.
@@return description
Adds a "Returns" section with the description text. This text
should describe the return type and permissible range of values.
@@see reference
Adds a "See Also" heading with a link or text entry that points
to reference. A doc comment can contain any number of @@see
tags, which are all grouped under the same heading. The @@see
tag has three variations; the third form below is the most com-
mon.
@@see string
Note: This form is broken in JDK 1.2 (prints none of the quoted
text) but is fixed in JDK 1.2.2. Adds a text entry for string.
No link is generated. The string is a book or other reference
to information not available by URL. javadoc distinguishes this
from the previous cases by looking for a double-quote (") as the
first character. For example:
@@see ""The Java Programming Language""
This generates text such as:
See Also::
""The Java Programming Language""
@@see <>label<>
Adds a link as defined by URL#value. The URL#value is a rela-
tive or absolute URL. javadoc distinguishes this from other
cases by looking for a less-than symbol (<<) as the first charac-
ter. For example:
@@see <>Java Spec<>
This generates a link such as:
See Also::
Java Spec
@@see package.class#member label
Adds a link, with visible text label, that points to the docu-
mentation for the specified name in the Java Language. The
label is optional; if omitted, the name appears instead as the
visible text, suitably shortened (see How a Name Is Displayed).
Use the label when you want the visible text to be abbreviated
or different from the name.
In only version 1.2, just the name but not the label would auto-
matically appear in <> HTML tags. Starting with JDK 1.2.2,
the <> is always included around the visible text, whether
or not a label is used.
]o package.class#member is any valid name in the Java Language
that is referenced (package, class, interface, constructor,
method, or field name), except that you replace the dot ahead
of the member name with a hash character (#). If this name is
in the documented classes, javadoc automatically creates a
link to it. To create links to external referenced classes,
use the -link option. Use either of the other two @@see forms
for referring to documentation of a name that does not belong
to a referenced class. This argument is described at greater
length below under Specifying a Name.
]o label is optional text that is visible as the link's label.
The label can contain white space. If a label is omitted,
then package.class.member will appear, suitably shortened rel-
ative to the current class and package (see How a Name Is Dis-
played).
]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 example below, an @@see tag (in the Character class)
refers to the equals method in the String class. The tag
includes both arguments, that is, the name
"String##equals(Object)" and the label "equals":
/****
** @@see String##equals(Object) equals
**/
The standard doclet produces HTML something like this:
<>
<- ><>See Also::<>
<
- ><><
>equals<><>
< >
The above looks something like this in a browser, where the
label is the visible link text:
See Also::
equals
Specifying 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 less than
fully-qualified, javadoc uses the normal Java compiler search
order to find it, further described below in Search order for
@@see. The name can contain whitespace within parentheses, such
as between method arguments.
The advantage to providing shorter, "partially-qualified" names
is that they require less typing and make less clutter in the
source code. The following table 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,...)
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
Referencing 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
@see package
]-----------------------------------------------------------]
The following notes apply to the above table:
]o The first set of forms (with no class or package) will cause
javadoc to search only through the current class's 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 steps 1-3). It will not search
the rest of the current package or other packages (search
steps 4-5).
]o If any method or constructor is entered as a name with no
parentheses, such as getValue, and if no field with the same
name exists, javadoc will correctly create a link to it, but
will print a warning message reminding you to add the paren-
theses and arguments. If this method is overloaded, javadoc
links to the first method that its search encounters, which is
unspecified.
]o Nested classes must be specified as outer.inner, not only
inner, for all forms.
]o As stated, the hash character (##), rather than a dot (.), sep-
arates a member from its class. This enables javadoc to
resolve ambiguities, since the dot also separates classes,
inner classes, packages, and subpackages. The hash character
is absolutely necessary in the forms above where it is the
first character. However, in other forms, javadoc is gener-
ally lenient and allows a dot if it does not produce an ambi-
guity, though it does print a warning.
Search Order for @@see:: javadoc will process an @@see tag that
appears in a source file (.java), package file (package.html),
or overview file (overview.html). In the latter two files, you
must fully qualify the name you supply with @@see. In a source
file, you can specify a name that is fully qualified or par-
tially qualified.
When javadoc encounters an @@see tag in a .java file that is not
fully qualified, it searches for the specified name in the same
order as the Java compiler would (except javadoc will not detect
certain namespace ambiguities, since it assumes the source code
is free of these errors). This search order is formally defined
in Chapter 6, "Names" of the Java Language Specification, modi-
fied by the Inner Classes Specification. javadoc 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 closest
first
3. Any superclasses and superinterfaces, searching closest
first
4. The current package
5. Any imported packages, classes and interfaces, searching in
the order of the import statement
javadoc continues to search recursively through steps 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 E's superclasses before E's enclosing
classes. In steps 4 and 5, javadoc does not search classes or
interfaces within a package in any specified order (that order
depends on the particular compiler). In step 5, javadoc will
look in java.lang, since that is automatically imported by all
programs.
javadoc will not necessarily look in subclasses, nor will it
look in other packages even if their documentation is being gen-
erated in the same run. For example, if the @@see tag is in
java.awt.event.KeyEvent class and refers to a name in the
java.awt package, javadoc will not look in that package unless
that class imports it.
How a Name is Displayed:: If label is omitted, then pack-
age.class.member will appear. In general, it will be suitably
shortened relative to the current class and package. By "short-
ened", we mean javadoc will display only the minimum name neces-
sary. For example, if the String.toUpperCase() method contains
references to a member of the same class and to a member of a
different class, the class name will be displayed only in the
latter case:
Type Example Displays As
of
Ref-
erence
@see tag @@see toLowerCase()
refers String##toLowerCase() (omits the class name)
to
member
of
the
same
class
@see @@see Character.toLowerCase(char)
tag Character##toLowerCase(char) (includes the class name)
refers
to
member
of a
differ-
ent
class
Examples of @@see:: The comment to the right shows how the name
would be displayed if the @@see tag is in a class in another
package, such as java.applet.Applet:
Example 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##MAXRADIX / Character.MAXRADIX
@@see <>Java Spec<> / Java Spec
@@see ""The Java Programming Language"" / "The Java Programming \
Language"
You can extend @@see to link to classes not being documented by
using the -link option. Notice that this works only for classes
that are referenced in a particular way as described at How an
Excluded Class ust Be Referenced for a Link to Appear.
@@since since-text
Adds a "Since" heading with the specified since-text to the gen-
erated documentation. The text has no special internal struc-
ture. This tag means that this change or feature has existed
since the software release specified by the since-text. For
example:
@@since 1.4
For source code in the Java platform, this tag indicates the
version of the Java platform API specification (not necessarily
when it was added to the reference implementation).
@@serial field-description include exclude
Used in the doc comment for a default serializable field.
An optional field-description should explain the meaning of the
field and list the acceptable values. If needed, the description
can span multiple lines. The standard doclet adds this informa-
tion to the serialized form page.
If a serializable field was added to a class some time after the
class was made serializable, a statement should be added to its
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 @@serial
exclude.
]o A private or package-private class that implements Serializ-
able is excluded unless that class (or its package) is marked
@@serial include.
Examples: The javax.swing package is marked @@serial exclude (in
package.html). The public class java.security.BasicPermission is
marked @@serial exclude. The package-private class
java.util.PropertyPermissionCollection is marked @@serial
include.
The tag @@serial at a class level overrides @@serial at a package
level.
The @@since tag should be added to each serializable field that
has been added since the initial version of a Serializable class
to identify when it was added.
For more information about how to use these tags, along with an
example, see "Documenting Serializable Fields and Data for a
Class," Section 1.6 of the Java Object Serialization Specifica-
tion. Also see the "Serialization FAQ," which covers questions
such as "Why do I see javadoc warnings stating that I am missing
@@serial tags for private fields if I am not running javadoc with
the -private switch?"
@@serialField field-name field-type field-description
Documents an ObjectStreamField component of a Serializable
class's serialPersistentFields member. One @@serialField tag
should be used for each ObjectStreamField component.
@@serialData data-description
A data-description documents the sequences and types of data,
specifically the optional data written by the writeObject method
and all data written by the Externalizable.writeExternal method.
The @@serialData tag can be used in the doc comment for the
writeObject, readObject, writeExternal, and readExternal meth-
ods.
@@throws class-name description
The @@throws and @@exception tags are synonyms. Adds a "Throws"
subheading to the generated documentation, with the class-name
and description text. The class-name is the name of the excep-
tion that can be thrown by the method. If this class is not
fully specified, the Javadoc tool uses the search order to look
up this class. A @@throws tag's comment documented in a super-
class or interface is inherited in two cases: (1) for a corre-
sponding exception declared in a throws clause of the subclass
and (2) for all runtime exceptions. If neither is the case and
you want to force the documentation to be inherited, then use
{@@inheritDoc}.
{@@value}
When used in a static field comment, displays the value of the
constant. These are the values displayed on the Constant Field
Values page. @@version version-text Adds a "Version" subheading
with the specified version-text to the generated docs when the
-version option is used. The text has no special internal
structure. A doc comment can contain at most one @@version tag.
Version normally refers to the version of the software (such as
the JDK) that contains this class or member.
WHERE TAGS CAN BE USED
The following sections describe where the tags can be used. Notice
that these four tags can be used in all doc comments: @@see, @@link,
@@since, @@deprecated.
OVERVIEW DOCUMENTATION 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). As in any other documentation comments, these tags
must appear after the description.
NOTE: The {@@link} tag has a bug in overview documents in version 1.2
\m( text appears properly but has no link. The {@@docRoot} tag does not
currently work in overview documents.
]--------------]
Overview Tags
]--------------]
@see
@since
@author
@version
{@link}
{@linkplain}
{@docRoot}
]--------------]
PACKAGE DOCUMENTATION TAGS
Package tags are tags that can appear in the documentation comment for
a package (which resides in the source file named package.html). The
@@serial tag can only be used here with the include or exclude argument.
]-------------]
Package Tags
]-------------]
@see
@since
@deprecated
@serial
@author
@version
{@link}
{@linkplain}
{@docRoot}
]-------------]
CLAS AND INTERFACE DOCUMENTATION TAGS
The following are tags that can appear in the documentation comment for
a class or interface. The @@serial tag can only be used here with the
include or exclude argument.
]---------------------]
Class/Interface Tags
]---------------------]
@see
@since
@deprecated
@serial
@author
@version
{@link}
{@linkplain}
{@docRoot}
]---------------------]
An example of a class comment:
/****
** A class representing a window on the screen.
** For example::
** <>
** Window win == new Window(parent);;
** win.show();;
** <>
**
** @@author Sami Shaio
** @@version 1.15,, 008/003/0000
** @@see java.awt.BaseWindow
** @@see java.awt.Button
**/
class Window extends BaseWindow {{
}}
FIELD DOCUMENTATION TAGS
The following are the tags that can appear in the documentation comment
for a field.
]-------------]
Field Tags
]-------------]
@see
@since
@deprecated
@serial
@serialField
{@link}
{@linkplain}
{@docRoot}
{@value}
]-------------]
An example of a field comment:
/****
** The X-coordinate of the component.
**
** @@see ##getLocation()
**/
int x == 1263732;;
CONSTRUCTOR AND METHOD DOCUMENTATION TAGS
The following are the tags that can appear in the documentation comment
for a constructor or method, except for {@@inheritDoc}, which cannot
appear in a constructor.
]------------------------]
ethod/Constructor Tags
]------------------------]
@see
@since
@deprecated
@param
@return
@throws (@exception)
@serialData
{@link}
{@linkplain}
{@inheritDoc}
{@docRoot}
]------------------------]
An example of a method doc comment:
/****
** Returns the character at the specified index. An index
** ranges from <>00<> to <>length() - 1<>.
**
** @@param index the index of the desired character.
** @@return the desired character.
** @@exception StringIndexOutOfRangeException
** if the index is not in the range <>00<>
** to <>length()-1<>.
** @@see java.lang.Character##charValue()
**/
public char charAt(int index) {{
}}
OPTIONS
The javadoc tool uses doclets to determine its output. javadoc uses
the default standard doclet unless a custom doclet is specified with
the -doclet option. javadoc provides a set of command-line options
that can be used with any doclet. These options are described below
under the sub-heading javadoc Options. The standard doclet provides an
additional set of command-line options that are described below, under
the sub-heading Options Provided by the Standard Doclet. All option
names are case-insensitive, though their arguments can be case-sensi-
tive.
The options are:
-1.1 -header -private
-author -help -protected
-bootclasspath -helpfile -public
-bottom -J -quiet
-breakiterator -link -serialwarn
-charset -linkoffline -source
-classpath -linksource -sourcepath
-d -locale -splitindex
-docencoding -nocomment -stylesheetfile
-docfilessubdirs -nodeprecated -subpackages
-doclet -nodeprecatedlist -tag
-docletpath -nohelp -taglet
-doctitle -noindex -tagletpath
-encoding -nonavbar -title
-exclude -noqualifier -use
-excludedocfilessubdir -nosince -verbose
-footers -overview -windowtitle
-group -package
JAVADOC OPTIONS
-overview path/filename
Specifies that javadoc should retrieve the text for the overview
documentation from the "source" file specified by path/filename
and place it on the Overview page (overview-summary.html). The
path/filename is relative to the -sourcepath.
While you can use any name you want for filename and place it
anywhere you want for path, a typical thing to do is to name it
overview.html and place it in the source tree at the directory
that contains the topmost package directories. In this loca-
tion, no path is needed when documenting packages, since -sour-
cepath will point 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 Example.
For information about the file specified by path/filename, see
overview comment file.
Notice that the overview page is created only if you pass into
javadoc two or more package names. For further explanation, see
HTML Frames.
The title on the overview page is set by -doctitle.
-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 these javadoc and doclet
command line options.
-doclet class
Specifies the class file that starts the doclet used in generat-
ing the documentation. Use the fully-qualified name. This
doclet defines the content and formats the output. If the
-doclet option is not used, javadoc 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.
For example, to call the MIF doclet, use:
-doclet com.sun.tools.doclets.mif.MIFDoclet
-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, the this specifies the
path to that jar file, as shown in the example below. You can
specify an absolute path or a path relative to the current
directory. If classpathlist contains multiple paths or JAR
files, they should be separated with a colon (:). This option
is not necessary if the doclet is already in the search path.
Example of path to jar file that contains the starting doclet
class file. Notice the jar filename is included.
-docletpath /home/user/mifdoclet/lib/mifdoclet.jar
Example of path to starting doclet class file. Notice the class
filename is omitted.
-docletpath /home/user/mifdoclet/classes/com/sun/tools/doclets/mif/
-1.1 This feature has been removed from javadoc 1.4. There is no
replacement for it. This option created documentation with the
appearance and functionality of documentation generated by
javadoc 1.1 (including never supporting nested classes). If you
need this option, use javadoc 1.2 or 1.3 instead.
-sourcepath sourcepathlist
Specifies the search paths for finding source files (.java) when
passing package names into the javadoc command. The sourcepath-
list can contain multiple paths by separating them with a colon
(:). javadoc will search in 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.
Notice that you can use the -sourcepath option only when passing
package names into the javadoc command; it will not locate .java
files passed into the javadoc command. (To locate .java files,
cd to that directory or include the path ahead of each file, as
shown at Documenting One or More Classes.) If -sourcepath is
omitted, javadoc uses the class path to find the source files
(see -classpath). Therefore, the default -sourcepath is the
value of class path. If -classpath is omitted and you are pass-
ing package names into javadoc, it looks in the current direc-
tory (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
In this case, you would specify the source path to
/home/user/src, the directory that contains com/mypackage, and
then supply the package name com.mypackage:
example% javadoc -sourcepath /home/user/src/ com.mypackage
This is easy to remember by noticing that if you concatenate the
value of the source path and the package name together and
change the dot to a slash "/", you end up with the full path to
the package:
/home/user/src/com/mypackage
To point to two source paths:
example% javadoc -sourcepath /home/u1/src::/home/u2/src \\
com.mypackage
-classpath classpathlist
Specifies the paths where javadoc looks for referenced classes
(.class); these are the documented classes plus any classes ref-
erenced by those classes. javadoc searches in all subdirecto-
ries of the specified paths. The class path list can contain
multiple paths by separating them with a colon. javadoc will
search in all subdirectories of the specified paths. Follow the
instructions in class path documentation for specifying class-
pathlist.
If -sourcepath is omitted, javadoc uses -classpath to find the
source files as well as class files (for backward compatibil-
ity). Therefore, if you want to search for source and class
files in separate paths, 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, you would
specify:
example% javadoc -classpath /home/user/lib -sourcepath \\
/home/user/src com.mypackage
As with other tools, if you do not specify -classpath, javadoc
uses the CLASPATH environment variable, if it is set. If both
are not set, javadoc searches for classes from the current
directory.
For an in-depth description of how javadoc uses -classpath to
find user classes as it relates to extension classes and boot-
strap classes, see How Classes Are Found.
-bootclasspath classpathlist
Specifies the paths where the boot classes reside. These are
nominally the Java platform classes. The bootclasspath is part
of the search path javadoc will use to look up source and class
files. See How Classes Are Found for more details. Separate
directories in dirlist with colons (:).
-extdirs dirlist
Specifies the directories where extension classes reside. These
are any classes that use the Java Extension mechanism. The
extdirs is part of the search path javadoc uses to look up
source and class files. See -classpath (above) for more
details. Separate directories in dirlist with colons (:).
-verbose
Provides more detailed messages while javadoc is running. With-
out 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 specifying the number of milliseconds to
parse each Java source file.
-quiet Shuts off non-error and non-warning messages, leaving only the
warnings and errors visible, making them easier to view. Also
suppresses the version string.
-locale languagecountryvariant
Important:: 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 will appear in English.
This is the only command-line option that is order-dependent.
Specifies the locale that javadoc uses when generating documen-
tation. The argument is the name of the locale, as described in
java.util.Locale documentation, such as enUS (English, United
States) or enUSWIN (Windows variant).
Specifying a locale causes javadoc to choose the resource files
of that locale for messages (strings in the navigation bar,
headings for lists and tables, help file contents, comments in
stylesheet.css, and so forth). It also specifies the sorting
order for lists sorted alphabetically, and the sentence separa-
tor to determine the end of the first sentence. It does not
determine the locale of the doc comment text specified in the
source files of the documented classes.
-encoding name
Specifies the source file encoding name, such as EUCJIS/SJIS.
If this option is not specified, the platform default converter
is used.
-Jflag Passes flag directly to the Java runtime system that runs
javadoc. Notice there must be no space between the -J and the
flag. For example, if you need to ensure that the system sets
aside 32 megabytes of memory in which to process the generated
documentation, then you would use this flag as follows:
example% javadoc -J-Xmx32m -J-Xms32m com.mypackage
-noindex
Omits the index from the generated docs. 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, otherwise found at the top and bottom of the generated
pages. Has no effect 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 converting the files to
PostScript or PDF for print 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, javadoc automatically creates a help file
help-doc.html that is hard-coded in javadoc. This option
enables you to override this default. The file name can be any
name and is not restricted to help-doc.html; javadoc will adjust
the links in the navigation bar accordingly. For example:
example% javadoc -helpfile /home/doc/myhelp.html java.awt
-stylesheetfile path/filename
Specifies the path of an alternate HTML stylesheet file. With-
out this option, javadoc automatically creates a stylesheet
file, stylesheet.css, that is hard-coded in javadoc. This
option enables you to override this default. The file name can
be any name and is not restricted to stylesheet.css. For exam-
ple:
example% javadoc -stylesheetfile \\
/home/doc/mystylesheet.css java.awt
-serialwarn
Generates compile-time warnings for missing @@serial tags. By
default, javadoc 1.2.2 (and later versions) generates no serial
warnings. (This is a reversal from earlier versions.) 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. For exam-
ple:
%% javadoc -charset ""iso-8859-1"" mypackage
would insert the following line in the head of every generated
page:
<>
This META tag is described in the HTML standard (4197265 and
4137321).
-docencoding name
Specifies the encoding of the generated HTML files.
EXAMPLES
You can run javadoc on entire packages or individual classes. 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.
Documenting One or ore Packages
To document a package, the source files (*.java) for that package must
be located in a directory having the same name as the package. If a
package name is made up of several identifiers (separated by dots),
each identifier represents a different directory. Thus, all java.awt
classes must reside in a directory named java/awt/. You can run
javadoc either of the following two ways: by changing directories (with
cd) or by using -sourcepath option. You cannot use wildcards to spec-
ify groups of packages.
]o Case 1 Changing to the package directory:: Change to the parent direc-
tory of the fully qualified package. Then run javadoc, supplying
names of one or more packages you want to document:
example% cd /home/src/
example% javadoc -d /home/html java.awt java.awt.event
]o Case 2 From any directory:: In this case, it does not matter what the
current directory is. Run javadoc supplying -sourcepath with the
parent directory of the fully qualified package, and supply names of
one or more packages you want to document:
example% javadoc -d /home/html -sourcepath /home/src \\
java.awt java.awt.event
Both 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 (/home/html). Because two or more packages are being gener-
ated, the document has three frames: for the list of packages, the list
of classes, and the main page.
Documenting One or ore Classes
The second way to run javadoc is by passing in one or more source files
(.java). You can run javadoc either of the following two ways: by
changing directories (with cd) or by fully specifying the path to the
.java files. Relative paths are relative to the current directory.
The -sourcepath option is ignored when passing in source files. You
can use command line wildcards, such as asterisk (*), to specify groups
of classes.
]o Case 1 Changing to the source directory:: Change to the directory
holding the .java files. Then run javadoc, supplying names of one or
more source files you want to document.
example% cd /home/src/java/awt
example% javadoc -d /home/html Button.java Canvas.java \\
Graphics**.java
This example generates HTML-formatted documentation for the classes
Button, Canvas, and classes beginning with Graphics. Because source
files rather than package names were passed in as arguments to
javadoc, the document has two frames, for the list of classes and the
main page.
]o Case 2 Changing to the package root directory:: This is useful for
documenting individual source files from different subpackages off
the same root. Change to the package root directory, and supply the
source files with paths from the root.
example% cd /home/src/
example% javadoc -d /home/html java/awt/Button.java \\
java/applet/Applet.java
This example generates HTML-formatted documentation for the classes
Button and Applet.
]o Case 3 From any directory:: In this case, it does not matter what the
current directory is. Run javadoc, supplying the absolute path (or
path relative to the current directory) to the .java files you want
to document:
example% javadoc -d /home/html /home/src/java/awt/Button.java \\
/home/src/java/awt/Graphics**.java
This example generates HTML-formatted documentation for the class
Button and classes beginning with Graphics.
Documenting Both Packages and Classes
You can document entire packages and individual classes at the same
time. Here is an example that mixes the two previous examples. You
can use -sourcepath for the path to the packages but not for the path
to the individual classes:
example% javadoc -d /home/html -sourcepath /home/src java.awt \\
/home/src/java/applet/Applet.java
This example generates HTML-formatted documentation for the package
java.awt and class Applet. (javadoc determines the package name for
Applet from the package declaration, if any, in the Applet.java source
file.)
Real World Example
javadoc has many useful options, some of which are more commonly used
than others. Here is effectively the command you need to run javadoc
on the Java platform API, using makefile variables (except not all
packages to be documented are listed):
example%% javadoc -sourcepath /jdk/src/share/classes /** Path for
source files **/
-d /jdk/build/api /** Destination directory **/
-use /** Adds ""Use"" files **/
-splitIndex /** Splits index A-Z **/
-windowtitle $$(WINDOWTITLE) /** Adds a window title **/
-doctitle $$(DOCTITLE) /** Adds a doc title **/
-header $$(HEADER) /** Adds running header text **/
-bottom $$(BOTO) /** Adds text at bottom **/
-group $$(GROUPCORE) /** Core heading for overview page **/
-group $$(GROUPEXT) /** Ext heading for overview page **/
-overview $$ (SCRDIR) /overview.html /** For overview text **/
-J-Xmx1800m /** For 1800MB memory **/
java.lang java.lang.reflect /** Packages to document **/
java.util java.io java.net java.applet
WINDOWTITLE == ''Java Platform 1.2 Final API Specification''
DOCTITLE == ''Java<><>TM<><> Platform 1.2 \\
Final API Specification''
HEADER == ''<>Java Platform 1.2<><
><>Final<>''
BOTOM == ''<><>Submit a bug or feature<><
><
>Java \\
is a trademark or registered trademark of Sun \\
icrosystems,, Inc. in the US and other countries.<
>\\
Copyright 1993-1998 Sun icrosystems,, Inc. 9001 San \\
Antonio Road,,<
>Palo Alto,, California,, 943003,, U.S.A.\\
<>''
GROUPCORE == ''""Core Packages"" ""java.**::com.sun.java.**::org.omg.**""
GROUPEXT == ''""Extension Packages"" ""javax.**""''
SRCDIR == ''/java/jdk/1.2/src/share/classes''
If you omit the -windowtitle option, javadoc copies the doc title to
the window title. The -windowtitle option would not be needed except
that the doc title contains HTML tags (which would appear as raw text
in the window title).
If you omit the -footer option, as done here, javadoc copies the header
text to the footer.
Other important options not needed in this example are -classpath and
-link.
ENVIRONMENT VARIABLES
CLASPATH Environment variable that provides the path that
javadoc uses to find user class files. This envi-
ronment variable is overridden by the -classpath
option. Separate your directories with a colon, as
for example:
.::/Users/vlh/classes::/Users/Shared/classes
SEE ALSO
javac(1), java(1), jdb(1), javah(1), javap(1)
See (or search java.sun.com) for the following:
The Javadoc Home Page @@
http:/java.sun.com/products/jdk/javadoc/index.html
Javadoc Enhancements @@
http:/java.sun.com/j2se/1.4/docs/tooldocs/javadoc/index.html
Javadoc FAQ @@
http:/java.sun.com/products/jdk/javadoc/faq.html
How to Write Doc Comments for Javadoc @@
http:/java.sun.com/products/jdk/javadoc/writingdoccomments.html
How Classes Are Found @@
http:/java.sun.com/j2se/1.4/docs/tooldocs/findingclasses.html#srcfiles
14 July 2000 javadoc(1)
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