o

Its name, after stripping off the ".java" suffix, is actually a legal class name (see Identifiers @
http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#40625 for legal characters)

o

Its directory path relative to the root of the source tree is actually a legal package name (after converting its separators to dots)

o

Its package statement contains the legal package name (specified in the previous bullet)

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

o

Javadoc Doclets

o

The -doclet command-line option

o

Javadoc Enhancements for details about improvements added in Javadoc.

o

Javadoc FAQ @
http://java.sun.com/j2se/javadoc/faq/index.html for answers to common questions, information about Javadoc-related tools, and workarounds for bugs.

o

How to Write Doc Comments for Javadoc @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html for more information about Sun conventions for writing documentation comments.

o

Requirements for Writing API Specifications @
http://java.sun.com/j2se/javadoc/writingapispecs/index.html - Standard requirements used when writing the Java 2 Platform Specification. It can be useful whether you are writing API specifications in source file documentation comments or in other formats. It covers requirements for packages, classes, interfaces, fields and methods to satisfy testable assertions.

o

Documentation Comment Specification @
http://java.sun.com/docs/books/jls/first_edition/html/18.doc.html - 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 edition.)

o

DocCheck Doclet @
http://java.sun.com/javadoc/doccheck - 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 @
http://java.sun.com/javadoc/mifdoclet - Can automate the generation of API documentation in MIF, FrameMaker and PDF formats. MIF is Adobe FrameMaker's interchange format.

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 of a program element written in the Java Language -- that is, the name of a package, class, interface, field, constructor or method. A name can be fully-qualified, such as java.lang.String.equals(java.lang.Object), or partially-qualified, such as equals(Object).

documented classes

The classes and interfaces for which detailed documentation is generated during a javadoc run. To be documented, the source files must be available, their source filenames or package names must be passed into the javadoc command, and they must not be filtered out by their access modifier (public, protected, package-private or private). We also refer to these as the classes included in the javadoc output, or the included classes.

included classes

Classes and interfaces whose details are documented during a run of the Javadoc tool. Same as documented classes.

excluded classes

Classes and interfaces whose details are not documented during a run of the Javadoc tool.

referenced classes

The classes and interfaces that are explicitly referred to in the definition (implementation) or doc comments of the documented classes and interfaces. Examples of references include return type, parameter type, cast type, extended class, implemented interface, imported classes, classes used in method bodies, @see, {@link}, {@linkplain}, and {@inheritDoc} tags. (Notice this definition has changed since 1.3 @
http://java.sun.com/j2se/1.3/docs/tooldocs/solaris/javadoc.html#referencedclasses.) When the Javadoc tool is run, it should load into memory all of the referenced classes in javadoc's bootclasspath and classpath. (The Javadoc tool prints a "Class not found" warning for referenced classes not found.) The Javadoc tool 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 generated during a javadoc run. In other words, these classes are not passed into the Javadoc tool on the command line. Links in the generated documentation to those classes are said to be external references or external links. For example, if you run the Javadoc tool 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.

o

package-info.java - Can contain a package declaration, package annotations, package comments and Javadoc tags. This file is new in JDK 5.0, and is preferred over package.html.

o

package.html - Can contain only package comments and Javadoc tags, no package annotations.

Note that while the comment separators /** and /* must be present, the leading asterisks on the intermediate lines can be omitted.

package.html - This file can contain a package comment of the following structure -- the comment is placed in the <body> element:

File: java/applet/package.html

Notice this is just a normal HTML file and does not include a package declaration. The content of the package comment file is 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 <body> and the first sentence. You can include package tags; as with any documentation comment, all block tags must appear after the main description. If you add a @see tag in a package comment file, it must have a fully-qualified name. For more details, see the 
example of package.html @

o

Copies the comment for processing. (For package.html, copies all content between <body> and </body> HTML tags. You can include a <head> section to put a <title>, source file copyright statement, or other information, but none of these will appear in the generated documentation.)

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 main descriptions.

o

Copies all content between <body> and </body> tags for processing.

o

Processes any overview tags that are present.

o

Inserts the processed text at the bottom of the overview page it generates, as shown in Overview Summary.

o

Copies the first sentence of the overview comment to the top of the overview summary page.

/**


 * This is the typical format of a simple documentation comment


 * that spans two lines.


 */

/** This comment takes up only one line. */

   /**


    * This is the class comment for the class Whatever.


    */


    import com.sun;   // MISTAKE - Important not to put import statement here


    public class Whatever {


    }

/**


 * This sentence would hold the main description for this doc comment.


 * @see java.lang.Object


 */

/**


 * @deprecated  As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}


 */

/**


 * This is a <b>doc</b> comment.


 * @see java.lang.Object


 */

/** 


 * The horizontal and vertical distances of point (x,y)


 */
public int x, y;      // Avoid this  

public int x

public int y

o

Automatically inherit comment to fill in missing text - When a main description, or @return, @param or @throws tag is missing from a method comment, the Javadoc tool copies the corresponding main 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 from the method further up the inheritance hierarchy. 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 presence of any main description or tag would prevent all comments from being inherited.

o

Explicitly inherit comment with {@inheritDoc} tag - Insert the inline tag {@inheritDoc} 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.

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

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) interface, 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):

-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 location, no path is needed when documenting packages, since -sourcepath 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.

Note 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 generating 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

For full, working examples of running a particular doclet, see Running the MIF Doclet @
http://java.sun.com/j2se/javadoc/mifdoclet/docs/mifdoclet.html#runningmifdoclet.

-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 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 (:) on Solaris and a semi-colon (;) on Windows. This option is not necessary if the doclet starting class 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/

For full, working examples of running a particular doclet, see Running the MIF Doclet @
http://java.sun.com/j2se/javadoc/mifdoclet/docs/mifdoclet.html#runningmifdoclet.

-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 (it never supported nested classes). If you need this option, use Javadoc 1.2 or 1.3 instead.

-source release

Specifies the version of source code accepted. The following values for release are allowed:

0u

0

javadoc accepts code containing assertions, which were introduced in JDK 1.4.

0u

0

javadoc does \f2not\fP support assertions, generics, or other language features introduced after JDK 1.3.

0u

??1??.5?????

+144u

-144u

??1??.4?????

+144u

-144u

??1??.3?????

+144u

-144u

0u

Use the value of release corresponding to that used when compiling the code with javac. 

-sourcepath  sourcepathlist

Specifies the search paths for finding source files (.java) when passing package names or -subpackages into the javadoc command. The sourcepathlist can contain multiple paths by separating them with a colon (:). The Javadoc tool 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. 

Note 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 passing package names into javadoc, it looks 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

In this case you would specify the sourcepath to /home/user/src, the directory that contains com/mypackage, and then supply the package name com.mypackage:

  % javadoc -sourcepath /home/user/src/ com.mypackage

This is easy to remember by noticing that if you concatenate the value of sourcepath 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:

  % javadoc -sourcepath /home/user1/src:/home/user2/src com.mypackage

-classpath  classpathlist

Specifies the paths where javadoc will look for referenced classes (.class files) -- these are the documented classes plus any classes referenced by those classes. The classpathlist can contain multiple paths by separating them with a colon (:). The Javadoc tool will search in all subdirectories of the specified paths. Follow the instructions in class path documentation for specifying classpathlist.

If -sourcepath is omitted, the Javadoc tool uses -classpath to find the source files as well as class files (for backward compatibility). 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:

  % javadoc -classpath /home/user/lib -sourcepath /home/user/src com.mypackage

As with other tools, if you do not specify -classpath, the Javadoc tool uses the CLASSPATH environment variable, if it is set. If both are not set, the Javadoc tool searches for classes from the current directory.

For an in-depth description of how the Javadoc tool uses -classpath to find user classes as it relates to extension classes and bootstrap classes, see How Classes Are Found.

As a special convenience, a class path element containing a basename of * is considered equivalent to specifying a list of all the files in the directory with the extension .jar or .JAR (a java program cannot tell the difference between the two invocations).
For example, if directory foo 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, even hidden ones, are included in the list. A classpath entry consisting simply of * expands to a list of all the jar files in the current directory. The CLASSPATH environment variable, where defined, will be similarly expanded. Any classpath wildcard expansion occurs before the Java virtual machine is started -- no Java program will ever see unexpanded wildcards except by querying the environment. For example; by invoking 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, as 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 systmes). Wildcards are not needed or allowed. Use -sourcepath to specify where to find the packages. This option is smart about not processing source files that are in the source tree but do not belong to the packages, as described at processing of source files.

For example:

  % javadoc -d docs -sourcepath /home/user/src -subpackages java:javax.swing

This command generates documentation for packages named "java" and "javax.swing" and all their subpackages.

You can use -subpackages in conjunction with -exclude to exclude specific packages.

-exclude  packagename1:packagename2:...

Unconditionally excludes the specified packages and their subpackages from the list formed by -subpackages. It excludes those packages even if they would otherwise be included by some previous or later -subpackages option. For example:

  % javadoc -sourcepath /home/user/src -subpackages java -exclude java.net:java.lang

would include java.io, java.util, and java.math (among others), but would exclude packages rooted at java.net and java.lang. Notice this excludes java.lang.ref, a subpackage of java.lang).

-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 the Javadoc tool will use to look up source and class files. See How Classes Are Found. for more details. Separate directories in classpathlist 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 the Javadoc tool will use 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. 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 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 appear, making them easier to view. Also suppresses the version string.

-breakiterator 

Uses the internationalized sentence boundary of java.text.BreakIterator to determine the end of the first sentence for English (all other locales already use BreakIterator), rather than an English language, locale-specific algorithm. By first sentence, we mean the first sentence in the main description of a package, class or member. This sentence is copied to the package, class or member summary, and to the alphabetic index.

From JDK 1.2 forward, the BreakIterator class is already used to determine the end of sentence for all languages but English. Therefore, the -breakiterator option has no effect except for English from 1.2 forward. English has its own default algorithm:

-locale  language_country_variant

Specifies the locale that javadoc uses when generating 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).

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 separator 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 encoding name of the source files, such as EUCJIS/SJIS. If this option is not specified, the platform default converter is used.

Also see -docencoding and -charset.

-Jflag

Passes flag directly to the runtime system java 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 call the -Xmx option of java as follows (-Xms is optional, as it only sets the size of initial memory, which is useful if you know the minimum amount of memory required):

   % javadoc -J-Xmx32m -J-Xms32m com.mypackage

To tell what version of javadoc you are using, call the "-version" option of java:

   % javadoc -J-version


   java version "1.2"


   Classic VM (build JDK-1.2-V, green threads, sunwjit)

(The version number of the standard doclet appears in its output stream.)

-d  directory

Specifies the destination directory where javadoc saves the generated HTML files. (The "d" means "destination.") Omitting this option causes the files to be saved to the current directory. The value directory can be absolute, or relative to the current working directory. As of 1.4, the destination directory is automatically created when javadoc is run.

For example, the following generates the documentation for the package com.mypackage and saves the results in the /home/user/doc/ directory:

  % javadoc -d /home/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 given 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, let's look at what might appear on the "Use" page for String. The getName() method in the java.awt.Font class returns type String. Therefore, getName() uses String, and you will find that method on the "Use" page for String.

Note that this documents only uses of the API, not the implementation. If 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.

You can access the generated "Use" page by first going to the class or package, then clicking on the "Use" link in the navigation bar.

-version

Includes the @version text in the generated docs. This text is omitted by default. To tell what version of the Javadoc tool 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 characters.

-windowtitle  title

Specifies the title to be placed in the HTML <title> tag. This 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, as the browser will not properly interpret them. Any internal quotation marks within title may have to be escaped. If -windowtitle is omitted, the Javadoc tool uses the value of -doctitle for this option.

  % javadoc -windowtitle "Java 2 Platform" com.mypackage

-doctitle  title

Specifies the title to be placed near the top of the overview summary file. The title will be placed as a centered, level-one heading directly beneath the upper navigation bar. The title may contain html tags and white space, though if it does, it must be enclosed in quotes. Any internal quotation marks within title may have to be escaped.

  % javadoc -doctitle "Java<sup><font size=\"-2\">TM</font></sup>" com.mypackage

-title  title

This option no longer exists. It existed only in Beta versions of Javadoc 1.2. It has been renamed to -doctitle. This option is being 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 will be placed to the right of the upper navigation bar. header may contain HTML tags and white space, though if it does, it must be enclosed in quotes. Any internal quotation marks within header may have to be escaped.

  % javadoc -header "<b>Java 2 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 will be placed to the right of the lower navigation bar. footer may contain html tags and white space, though if it does, it must be enclosed in quotes. Any internal quotation marks within footer may have to be escaped.

-bottom  text

Specifies the text to be placed at the bottom of each output file. The text will be placed at the bottom of the page, below the lower navigation bar. The text may contain HTML tags and white space, though if it does, it must be enclosed in quotes. Any internal quotation marks within text may have to be escaped.

-link  extdocURL

Creates links to existing javadoc-generated documentation of external referenced classes. It takes one argument:

You can specify multiple -link options in a given javadoc run to link to multiple documents. Choosing between -linkoffline and -link:
Use -link:

Use -linkoffline:

Example using absolute links to the external docs - Let's say you want to link to the java.lang, java.io and other Java 2 Platform packages at http://java.sun.com/j2se/1.5.0/docs/api @
http://java.sun.com/j2se/1.5.0/docs/api, The following command generates documentation for the package com.mypackage with links to the Java 2 Platform packages. The generated documentation will contain links to the Object class, for example, in the class trees. (Other options, such as -sourcepath and -d, are not shown.)

  % javadoc -link http://java.sun.com/j2se/1.5.0/docs/api com.mypackage

Example using relative links to the external docs - Let's say you have two packages whose docs are generated in different runs of the Javadoc tool, and those docs are separated by a relative path. In this example, the packages are com.apipackage, an API, and com.spipackage, an SPI (Service Provide Interface). You want the documentation to reside in docs/api/com/apipackage and docs/spi/com/spipackage. Assuming the API package documentation is already generated, and that docs is the current directory, you would document the SPI package with links to the API documentation by running:

  % javadoc -d ./spi -link ../api com.spipackage

Notice the -link argument is relative to the destination directory (docs/spi).

Details - The -link option enables you to link to classes referenced to by your code but not documented in the current javadoc 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, for instance, third party documentation to link to java.* documentation on http://java.sun.com.

Omit the -link option for javadoc to create links only to API within the documentation it is generating in the current run. (Without the -link option, the Javadoc tool does not create links to documentation for external references, because it does not know if or where that documentation exists.)

This option can create links in several places in the generated documentation.

Another use is for cross-links between sets of packages: Execute javadoc on one set of packages, then run javadoc again on another set of packages, creating links both ways between both sets.

How a Class Must be Referenced - For a link to an external referenced class to actually 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:

An important corollary is that when you use the -link option, there may be many links that unintentionally do not appear due to this constraint. (The text would appear without a hypertext link.) You can detect these by the warnings they emit. The most innocuous way to properly reference a class and thereby add the link would be to import that class, as shown above.

Package List - The -link option requires that a file named package-list, which is generated by the Javadoc tool, exist at the URL you specify with -link. 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 tool looks for a file named package-list at the given URL, reads in the package names and then links to those packages at that URL.

For example, the package list for the Java 2 Platform 5.0 API is located at http://java.sun.com/j2se/1.5.0/docs/api/package-list @
http://java.sun.com/j2se/1.5.0/docs/api/package-list. and starts out as follows:

  java.applet  


  java.awt


  java.awt.color


  java.awt.datatransfer


  java.awt.dnd


  java.awt.event


  java.awt.font


  etc.

When javadoc is run without the -link option, when it encounters a name that belongs to an external referenced class, it prints the name with no link. However, when the -link option is used, the Javadoc tool searches the package-list file at the specified extdocURL location for that package name. If it finds the package name, it prefixes the name with extdocURL.

In order for there to be no broken links, all of the documentation for the external references must exist at the specified URLs. The Javadoc tool will not check that these pages exist -- only that the package-list exists.

Multiple Links - You can supply multiple -link options to link to any number of external generated documents.   Javadoc 1.2 has a known bug which prevents you from supplying more than one -link command. This was fixed in 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" may be required when cross-linking two or more documents that have not previously been generated. In other words, if package-list does not exist for either document, when you run the Javadoc tool on the first document, the package-list will not yet exist for the second document. Therefore, to create the external links, you must re-generate the first document after generating 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 it if you're certain of the package names). Then generate the second document with its external links. The Javadoc tool prints a warning if a needed external package-list file does not exist.

-linkoffline  extdocURL  packagelistLoc

This option is a variation of -link; they both create links to javadoc-generated documentation for external referenced classes. Use the -linkoffline option when linking to a document on the web when the Javadoc tool itself is "offline" -- that is, it cannot access the document through a web connection.

More specifically, use -linkoffline if the external document's package-list file is not accessible or does not exist at the extdocURL location but does exist at a different location, which can be specified by packageListLoc (typically local). Thus, if extdocURL is accessible only on the World Wide Web, -linkoffline removes the constraint that the Javadoc tool have a web connection when generating the documentation.

Another use is as a "hack" to update docs: After you have run javadoc on a full set of packages, then you can run javadoc again on onlya smaller set of changed packages, so that the updated files can be inserted back into the original set. Examples are given below.

The -linkoffline option takes two arguments -- the first for the string to be embedded in the <a href> links, the second telling it where to find package-list:

You can specify multiple -linkoffline options in a given javadoc run. (Prior to 1.2.2, it could be specified only once.)

Example using absolute links to the external docs - Let's say you want to link to the java.lang, java.io and other Java 2 Platform packages at http://java.sun.com/j2se/1.5.0/docs/api, but your shell does not have web access. You could open the package-list file in a browser at http://java.sun.com/j2se/1.5.0/docs/api/package-list @
http://java.sun.com/j2se/1.5.0/docs/api/package-list, save it to a local directory, and point to this local copy with the second argument, packagelistLoc. In this example, the package list file has been saved to the current directory "." . The following command generates documentation for the package com.mypackage with links to the Java 2 Platform 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://java.sun.com/j2se/1.5.0/docs/api . com.mypackage

Example using relative links to the external docs - It's not very common to use -linkoffline with relative paths, for the simple reason that -link usually suffices. When using -linkoffline, the package-list file is generally local, and when using relative links, the file you are linking to is also generally local. So it is usually unnecessary to give a different path for the two arguments to -linkoffline. When the two arguments are identical, you can use -link. See the -link relative example.

Manually Creating a package-list File - If a package-list file does not yet exist, but you know what package names your document will link to, you can create your own copy of this file by hand 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. Likewise, two companies can share their unpublished package-list files, enabling them to release their cross-linked documentation simultaneously.

Linking to Multiple Documents - You can include -linkoffline once for each generated document you want to refer to (each option is shown on a separate line for clarity):

% javadoc -linkoffline extdocURL1 packagelistLoc1 \
          -linkoffline extdocURL2 packagelistLoc2 \
          ...

Updating docs - Another use for -linkoffline option is useful if your project has dozens or hundreds of packages, if you have already run javadoc on the entire tree, and now, in a separate run, you want to quickly make some small changes and re-run javadoc on just a small portion of the source tree. This is somewhat of a hack in that it works properly only if your changes are only to doc 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, you create a new destination directory (call it update) for this new small run. Let's say the original destination directory was named html. In the simplest example, cd to the parent of html. Set the first argument of -linkoffline 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 tool is done, copy these generated class pages in update/com/package (not the overview or index), over 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 will necessarily be accessible via 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

and the link to the source code of the getLabel() method in the Button class would be 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 given -group option, the packages matching the list of packagepattern expressions appear in a table with the heading groupheading.

If you do not supply any -group option, all packages are placed in one group with the heading "Packages". If the all groups do not include all documented packages, any leftover packages appear in a separate group with the heading "Other Packages".

For example, the following option separates the four documented packages into core, extension and other packages. Notice the trailing "dot" does not appear in "java.lang*" -- including the dot, such as "java.lang.*" would omit the java.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

This results in the groupings:

-nodeprecated

Prevents the generation of any deprecated API at all in the documentation. This does what -nodeprecatedlist does, plus it does not generate any deprecated API throughout the rest of the documentation. This is useful when writing code and you don't want to be distracted by the deprecated code.

-nodeprecatedlist

Prevents the generation of the file containing the list of deprecated APIs (deprecated-list.html) and the link in the navigation bar to that page. (However, javadoc continues to generate the deprecated API throughout the rest of the document.) This is useful if your source code contains no deprecated API, and you want to make the navigation bar cleaner.

-nosince

Omits from the generated docs the "Since" sections associated with the @since tags.

-notree

Omits the class/interface hierarchy pages from the generated docs. 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 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 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 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, the Javadoc tool automatically creates a help file help-doc.html that is hard-coded in the Javadoc tool. This option enables you to override this default. The filename can be any name and is not restricted to help-doc.html -- the Javadoc tool will adjust the links in the navigation bar accordingly. For example:

  % javadoc -helpfile /home/user/myhelp.html java.awt

-stylesheetfile  path/filename

Specifies the path of an alternate HTML stylesheet file. Without this option, the Javadoc tool automatically creates a stylesheet file stylesheet.css that is hard-coded in the Javadoc tool. This option enables you to override this default. The filename can be any name and is not restricted to stylesheet.css. For example:

  % javadoc -stylesheetfile /home/user/mystylesheet.css com.mypackage

-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. The name should be a preferred MIME name as given in the IANA Registry @
http://www.iana.org/assignments/character-sets. For example:

  % javadoc -charset "iso-8859-1" mypackage

would insert 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 @
http://www.w3.org/TR/REC-html40/charset.html#h-5.2.2. (4197265 and 4137321)

Also see -encoding and -docencoding.

-docencoding  name

Specifies the encoding of the generated HTML files. The name should be a preferred MIME name as given in the IANA Registry @
http://www.iana.org/assignments/character-sets. If you omit this option but use -encoding, then the encoding of the generated HTML files is determined by -encoding. Example:

  % javadoc -docencoding "ISO-8859-1" mypackage

Also see -encoding and -charset.

-keywords

Adds HTML meta keyword tags to the generated file for each class. These tags can help the page be found by search engines that look for meta tags. (Most search engines that search the entire Internet do not look at meta tags, because pages can misuse them; but search engines offered by companies that confine their search 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 tool to interpret a simple, one-argument custom block tag @tagname in doc comments. So the Javadoc tool can "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. To use a colon in tagname, see Use of Colon in Tag Name.

The -tag option outputs the tag's heading taghead in bold, followed on the next line by the text from its single argument, as shown in the example below. Like any block tag, this argument's text can contain inline tags, which are also interpreted. The output is similar to standard one-argument tags, such as @return and @author. Omitting taghead causes tagname to appear as the heading.

Placement of tags - The Xaoptcmf part of the argument determines 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 that can be used anywhere in the source code is:

    -tag todo:a:"To Do:"

If you wanted @todo to be used only with constructors, methods and fields, you would use:

    -tag todo:cmf:"To Do:"

Notice the last colon (:) above is not a parameter separator, but is part of the heading text (as shown below). You would use either tag option for source code that contains the tag @todo, such as:

     @todo The documentation for this method needs work.

Use of Colon in Tag Name - A colon can be used in a tag name if it is escaped with a backslash. For this doc comment:

    /**


     * @ejb:bean


     */

use this tag option:

    -tag ejb\\:bean:a:"EJB Bean:"

Spell-checking tag names (Disabling tags) - Some developers put custom tags in the source code that they don't always want to output. In these cases, it is important to list all tags that are present in the source code, enabling the ones you want to output and disabling the ones you don't want to output. The presence of X disables the tag, while its absence enables the tag. This gives the Javadoc tool enough information to know if a tag it encounters is unknown, probably the results of a typo or a misspelling. It 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 @todo is a tag that you want to suppress on output, you would use:

    -tag todo:Xcmf:"To Do:"

or, if you'd rather keep it simple:

    -tag todo:X

The syntax -tag todo:X works even if @todo is defined by a taglet.

Order of tags - The order of the -tag (and -taglet) options determine 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 -tag is missing, then the position of -taglet 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 -taglet and -tag both have the name "todo", the one that appears last on the command line will determine its 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 @example is a tag that might be encountered in the source code that should not be output during this run. Notice that if you use @argfile, you can put the tags on separate lines in an argument file like this (no line continuation characters needed):

   -tag param


   -tag return


   -tag todo:a:"To Do:"


   -tag throws


   -tag see


   -tag example:X

When javadoc parses the doc comments, any tag encountered that is neither a standard tag nor passed in with -tag or -taglet is considered unknown, and a warning is thrown.

The standard tags are initially stored internally in a list in their default order. Whenever -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, it remains in its default position.

Avoiding Conflicts - If you want to slice out your own namespace, you can use a dot-separated naming convention similar to that used for packages: com.mycompany.todo. Sun 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 Sun. In other words, if you create a tag or taglet @todo, it will always have the same behavior you define, even if Sun 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, it should probably be a javadoc tag; otherwise, it should be an annotation. See Comparing Annotations and Javadoc Tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.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 class. 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:

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. So 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. Here is an example that inserts the "To Do" taglet after "Parameters" and ahead of "Throws" in the generated pages:

    -taglet com.sun.tools.doclets.ToDoTaglet


    -tagletpath /home/taglets 


    -tag return


    -tag param


    -tag todo


    -tag throws


    -tag see

Alternatively, you can use the -taglet option in place of its -tag option, but that may be harder to read.

-tagletpath  tagletpathlist

Specifies the search paths for finding taglet class files (.class). The tagletpathlist can contain multiple paths by separating them with a colon (:). The Javadoc tool will search in all subdirectories of the specified paths.

-docfilessubdirs 

Enables deep copying of "doc-files" directories. In other words, subdirectories and all contents are recursively copied to the destination. For example, the directory doc-files/example/images and all its contents would now be copied. There is also an option to exclude subdirectories.

-excludedocfilessubdir  name1:name2...

Excludes any "doc-files" subdirectories with the given names. This prevents the copying of SCCS and other source-code-control subdirectories.

-noqualifier  all  |  packagename1:packagename2:...

Omits qualifying package name from ahead of class names in output. The argument to -noqualifier is either "all" (all package qualifiers are omitted) or a colon-separate list of packages, with wildcards, to be removed as qualifiers. The package name is removed from places where class or interface names appear.

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 above behavior, the name can be suitably shortened -- see How a name is displayed. This rule is in effect whether or not -noqualifier is used.

-notimestamp 

Suppresses the timestamp, which is hidden in an HTML comment in the generated HTML near the top of each page. Useful when you want to run javadoc on two source bases and diff them, as it prevents timestamps from causing a diff (which would otherwise be a diff on every page). The timestamp includes the javadoc version number, and currently looks like this:

     <!-- Generated by javadoc (build 1.5.0-internal) on Tue Jun 22 09:57:24 PDT 2004 -->

-nocomment 

Suppress the entire comment body, including the main description and all tags, generating only declarations. This option enables re-using source files originally intended for a different purpose, to produce skeleton HTML documentation at the early stages of a new project.

o

Case 1 - Run recursively starting from one or more packages - This example uses -sourcepath so javadoc 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).

  % javadoc -d /home/html -sourcepath /home/src -subpackages java -exclude java.net:java.lang

To also traverse down other package trees, append their names to the -subpackages argument, such as java:javax:org.xml.sax.

o

Case 2 - Run on explicit packages after changing to the "root" source directory - Change to the parent directory of the fully-qualified package. Then run javadoc, supplying names of one or more packages you want to document:

  % cd /home/src/


  % javadoc -d /home/html java.awt java.awt.event

o

Case 3 - Run from any directory on explicit packages in a single directory tree - In this case, it doesn't matter what the current directory is. Run javadoc supplying -sourcepath with the parent directory of the top-level package, and supplying names of one or more packages you want to document:

  % javadoc -d /home/html -sourcepath /home/src java.awt java.awt.event

o

Case 4 - Run from any directory on explicit packages in multiple directory trees - This is the same as case 3, but for packages in separate directory trees. Run javadoc supplying -sourcepath with the path to each tree's root (colon-separated) and supply names of one or more packages you want to document. All source files for a given package do not need to be located under a single root directory -- they just need to be found somewhere along the sourcepath.

  % javadoc -d /home/html -sourcepath /home/src1:/home/src2 java.awt java.awt.event

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.

  % cd /home/src/java/awt


  % 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.

  % cd /home/src/


  % 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 doesn't 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.

  % 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.

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 = 'Java 2 Platform v1.2 API Specification'
DOCTITLE = 'Java<sup><font size="-2">TM</font></sup> 2 Platform v1.2 API Specification'
HEADER = '<b>Java 2 Platform </b><br><font size="-1">v1.2</font>'
BOTTOM = '<font size="-1"><a href="http://java.sun.com/cgi-bin/bugreport.cgi">Submit


    a bug or feature</a><br><br>Java is a trademark or registered trademark 


    of Sun Microsystems, Inc. in the US and other countries.<br>Copyright 1993-1999    


    Sun Microsystems, Inc. 901 San Antonio Road,<br>Palo Alto, California, 94303, U.S.A.  


    All Rights Reserved.</font>'
GROUPCORE = '"Core Packages" "java.*:com.sun.java.*:org.omg.*"'
GROUPEXT  = '"Extension Packages" "javax.*"'
SRCDIR = '/java/jdk/1.2/src/share/classes'

o

If you omit the -windowtitle option, the Javadoc tool copies the doc title to the window title. The -windowtitle text is basically the same as the -doctitle but without HTML tags, to prevent those tags from appearing as raw text in the window title.

o

If you omit the -footer option, as done here, the Javadoc tool copies the header text to the footer.

o

Other important options you might want to use but not needed in this example are -classpath and -link.

o

Javadoc FAQ - Commonly-encountered bugs and troubleshooting tips can be found on the Javadoc FAQ @
http://java.sun.com/j2se/javadoc/faq/index.html#B

o

Bugs and Limitations - You can also see some bugs listed at Important Bug Fixes and Changes @
http://java.sun.com/j2se/1.5.0/fixedbugs/index.html.

o

Version number - See version numbers.

o

Documents only legal classes - When documenting a package, javadoc only reads files whose names are composed of legal class names. You can prevent javadoc from parsing a file by including, for example, a hyphen "-" in its filename.

o

"error: cannot read: Class1.java" the Javadoc tool is trying to load the class Class1.java in the current directory. The class name is shown with its path (absolute or relative), which in this case is the same as ./Class1.java.