3 Javadoc Command

The javadoc command-line synopsis is javadoc [options] [packagenames] [sourcefiles] [@files]. The options can either be Doclet options or Standard Doclet options. The javadoc command can also be run programmatically.

This topic contains the following sections:

Javadoc Doclets

You use the javadoc tool and its options to generate HTML pages of API documentation from Java source files.

Javadoc Doclet Options

The javadoc command has options for doclets. The Standard Doclet provides additional options.

The javadoc command uses doclets to determine its output and the default Standard Doclet unless a custom doclet is specified with the -doclet option. While option names are not case-sensitive, their arguments are.

Synopsis

javadoc  [packages|source-files] [options][@files]

packages

Names of packages that you want to document, separated by spaces, for example java.lang java.lang.reflect java.awt. If you want to also document the subpackages, then use the -subpackages option to specify them.

By default, the javadoc command looks for the specified packages in the current directory and subdirectories. Use the -sourcepath option to specify the list of directories where to look for packages.

source-files

Names of Java source files that you want to document, separated by spaces, for example, Class.java Object.java Button.java. By default, the javadoc command looks for the specified classes in the current directory. However, you can specify the full path to the class file and use wildcard characters, for example /home/src/java/awt/Graphics*.java. You can also specify the path relative to the current directory.

options

Command-line options, separated by spaces.

@files

Names of files that contain a list of javadoc command options, package names, and source file names in any order.

Description

The javadoc command parses the declarations and documentation comments in a set of Java source files and produces a corresponding set of HTML pages that describe (by default) the public and protected classes, nested classes (but not anonymous inner classes), interfaces, constructors, methods, and fields. You can use the javadoc command to generate the API documentation or the implementation documentation for a set of source files.

You can run the javadoc command on entire packages, individual source files, or both. When documenting entire packages, you can use either the -subpackages option to recursively traverse a directory and its subdirectories, or to pass in an explicit list of package names. When you document individual source files, pass in a list of Java source file names.

Conformance

The Standard Doclet does not validate the content of documentation comments for conformance, nor does it attempt to correct any errors in documentation comments. Anyone running javadoc is advised to be aware of the problems that may arise when generating non-conformant output or output containing executable content, such as JavaScript. The Standard Doclet does provide the doclint feature to help developers detect common problems in documentation comments; but, it is also recommended to check the generated output with any appropriate conformance and other checking tools.

For more details on the conformance requirements for HTML5 documents, see Conformance requirements in the HTML5 Specification. For more details on security issues related to web pages, see the Open Web Application Security Project (OWASP) page.

Process Source Files

The javadoc command processes files that end in the source file extension and other files described in Source Files. If you run the javadoc command by passing in individual source file names, then you can determine exactly which source files are processed. However, that isn't how most developers want to work because it's simpler to pass in package names. The javadoc command can be run three ways, without explicitly specifying the source file names. You can pass in package names, use the -subpackages option, or use wild cards with source file names. In these cases, the javadoc command processes a source file only when the file fulfills all of the following requirements:

The file name prefix (with .java removed) is a valid class name.
The path name relative to the root of the source tree is a valid package name after the separators are converted to dots.
The package statement contains the valid package name.

Processing Links

During a run, the javadoc command adds cross-reference links to package, class, and member names that are being documented as part of that run. Links appear in the following places:

Declarations (return types, argument types, and field types)
See Also sections that are generated from @see tags
Inline text generated from {@link} tags
Exception names generated from @throws tags
Specified by links to interface members and Overrides links to class members
Summary tables listing packages, classes, and members
Package and class inheritance trees
The index

Processing Details

The javadoc command produces one complete document every time it runs. It doesn't perform incremental builds that modify or directly incorporate the results from earlier runs. However, the javadoc command can link to results from other runs.

The javadoc command implementation requires and relies on the Java compiler. The javadoc command calls part of the javac command to compile the declarations and ignore the member implementations. The javadoc command builds a rich internal representation of the classes that includes the class hierarchy and use relationships to generate the HTML documentation. The javadoc command also picks up user-supplied documentation from documentation comments in the source code.

The javadoc command can run on source files that are pure stub files with no method bodies. This means that you can write documentation comments and run the javadoc command in the early stages of design before API implementation.

Relying on the compiler ensures that the HTML output corresponds exactly with the actual implementation, which may rely on implicit, rather than explicit, source code. For example, the javadoc command documents default constructors that are present in the compiled class files but not in the source code.

In many cases, the javadoc command lets you generate documentation for source files with incomplete or erroneous code. You can generate documentation before any debugging and troubleshooting is done. The javadoc command does primitive checking of documentation comments.

When the javadoc command builds its internal structure for the documentation, it loads all referenced classes. Because of this, the javadoc command must be able to find all referenced classes, and whether they're bootstrap classes, extensions, or user classes.

Javadoc Doclets

You can customize the content and format of the javadoc command output with doclets. The javadoc command has a default built-in doclet, called the Standard Doclet, that generates HTML-formatted API documentation. You can write your own doclet to generate HTML, XML, MIF, RTF or whatever output format you want.

When a custom doclet isn't specified with the -doclet option, the javadoc command uses the default Standard Doclet. The javadoc command has several options that are available regardless of which doclet is being used. The Standard Doclet adds a supplementary set of command-line options.

Javadoc Doclet Options

The javadoc tool supports documentation comments in module declarations. It has command-line options, such as --module-path, --upgrade-module-path, or --module-source-path to configure the set of modules to be documented, and generates a new summary page for any modules being documented. The module-related options are available for generating documentation. The following options are the core options that are available to all doclets:

--add-modules module(,module)*

Specifies the root modules to resolve in addition to the initial modules, or all modules on the module path if <module> is ALL-MODULE-PATH.

--add-exports module/package=other-module(,other-module)*

Specifies a package that's to be considered as exported from its defining module to additional modules, or to all unnamed modules if other-module is ALL-UNNAMED.

--add-reads module/package=other-module(,other-module)

Specifies additional modules to be considered as required by a given module. other-module is ALL-UNNAMED to require the unnamed module.

-bootclasspath classpathlist

Specifies the paths where the boot classes reside. These are typically the Java platform classes. The bootclasspath is part of the search path that the javadoc command uses to look up source and class files.

To separate directories in the classpathlist parameters, use one of the following delimiters:

Oracle Solaris, Linux, and macOS: colon (:)
Windows: semicolon (;)

Note:

The -bootclasspath option is only allowed if you are working to generate documentation for older versions of the Java platform, such as using JDK 6, 7, or 8 for -source, -target, or --release.

-breakiterator

Uses the internationalized sentence boundary of java.text.BreakIterator to determine the end of the first sentence in the main description of a package, class, or member for English. All other locales already use the BreakIterator class, rather than an English language, locale-specific algorithm. The first sentence is copied to the package, class, or member summary and to the alphabetic index. The BreakIterator class is used to determine the end of a sentence for all languages except for English as follows:

English default sentence-break algorithm: Stops at a period followed by a space or an HTML block tag, such as .
Break iterator sentence-break algorithm: Stops at a period, question mark, or exclamation point followed by a space when the next word starts with a capital letter. This is meant to handle most abbreviations (such as "The serial no. is valid", but won't handle "Mr. Smith"). The -breakiterator option doesn't stop at HTML tags or sentences that begin with numbers or symbols. The algorithm stops at the last period in ../filename, even when it's embedded in an HTML tag.
A question mark always ends the first sentence: If a double quotation mark follows the question mark, then the double quotation mark also gets included in the first sentence, but that character then ends the sentence.

-classpath path or --class-path path or -cp path

Specifies the paths where the javadoc command searches for referenced classes. These are the documented classes plus any classes referenced by those classes.

CLASSPATH is the environment variable that provides the path that the javadoc command uses to find user class files. This environment variable is overridden by the -classpath option. To separate directories, use one of the following delimiters: a semicolon for Windows or a colon for Oracle Solaris.

Oracle Solaris, Linux, and macOS: To separate multiple paths, use a colon (:). For example, .:/home/classes:/usr/local/java/classes

Windows: To separate multiple paths, use a semicolon (;). For example, .;C:\classes;C:\home\java\classes

The javadoc command searches all subdirectories of the specified paths.

If you omit -sourcepath, then the javadoc command uses -classpath to find the source files and class files (for backward compatibility). If you want to search for source and class files in separate paths, then use both -sourcepath and -classpath.

Oracle Solaris, Linux, and macOS: For example, if you want to document com.mypackage, whose source files reside in the directory /home/user/src/com/mypackage, and if this package relies on a library in /home/user/lib, then you use the following command:

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

Windows: For example, if you want to document com.mypackage, whose source files reside in the directory \user\src\com\mypackage, and if this package relies on a library in \user\lib, then you would use the following command:

javadoc -sourcepath \user\lib -classpath \user\src com.mypackage

Similar to other tools, if you don't specify -classpath, then the javadoc command uses the CLASSPATH environment variable when it's set. If both aren't set, then the javadoc command searches for classes from the current directory.

A class path element that contains a base name of * is considered equivalent to specifying a list of all the files in the directory with the extension .jar or .JAR.

For example, if the directory mydir contains a.jar and b.jar, then the class path element foo/* is expanded to a a.jar:b.JAR, except that the order of JAR files is unspecified. All JAR files in the specified directory including hidden files are included in the list. A class path entry that consists of * expands to a list of all the JAR files in the current directory. The CLASSPATH environment variable is similarly expanded. Any class path wildcard expansion occurs before the Java Virtual Machine (JVM) starts. No Java program ever sees unexpanded wild cards except by querying the environment, for example, by calling System.getenv ("CLASSPATH").

-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 isn't used, then the javadoc command uses the Standard Doclet for generating the default HTML format. This class must implement the jdk.javadoc.doclet.Doclet interface. The path to this starting class is defined by the -docletpath option.

-docletpath path

Specifies the path to the doclet-starting class file (specified with the -doclet option) and any JAR files that it depends on. If the starting class file is in a JAR file, then this option specifies the path to that JAR file. You can specify an absolute path or a path relative to the current directory. This option isn't necessary when the doclet-starting class is already in the search path.

-encoding name

Specifies the encoding name of the source files, such as EUCJIS/SJIS. If this option isn't specified, then the platform default converter is used.

-exclude pkglist

Unconditionally, excludes the specified packages and their subpackages from the list formed by -subpackages. It excludes those packages even when they would otherwise be included by some earlier or later -subpackages option.

The following example would include java.io, java.util, and java.math (among others), but would exclude packages rooted at java.net and java.lang. Notice that these examples exclude java.lang.ref, which is a subpackage of java.lang.

Oracle Solaris, Linux, and macOS:

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

Windows:

javadoc -sourcepath \user\src -subpackages java -exclude java.net:java.lang

--expand-requires value

Instructs the javadoc command to expand the set of modules to be documented. By default, only the modules given explicitly on the command line are documented. This option supports the following values:

transitive: Additionally includes all the required transitive dependencies of those modules.
all: Includes all dependencies.

-extdirs dirlist

Overrides the ___location of installed extensions. These are any classes that use the Java Extension mechanism. The extdirs option is part of the search path that the javadoc command uses to look up source and class files. See the -classpath option for more information. To separate directories in dirlist, use a semicolon (;) for Windows and a colon (:) for Oracle Solaris, Linux, and macOS.

-help OR --help

Displays the online help, which lists all of the javadoc and doclet command-line options.

-J flag

Passes flag directly to the Java Runtime Environment (JRE) that runs the javadoc command. For example, if you must ensure that the system sets aside 32 MB of memory to generate the documentation, then you need to call the -Xmx option as follows: javadoc -J-Xmx32m -J-Xms32m com.mypackage. Be aware that -Xms is optional because it only sets the size of only initial memory, which is useful when you know the minimum amount of memory required.

There's no space between the J and the flag.

Use the -version option to find out what version of the javadoc command you are using. The version number of the Standard Doclet appears in its output stream.

--limit-modules module(,module)*

Limits the number of observable modules.

-locale name

Specifies the locale that the javadoc command uses when it generates documentation. The argument is the name of the locale, as described in the java.util.Locale documentation, such as en_US (English, United States) or en_US_WIN (Windows variant).

Note: The -locale option must be placed ahead (to the left) of any options provided by the Standard Doclet or any other doclet. Otherwise, the navigation bars appear in English. This is the only command-line option that depends on order.

Specifying a locale causes the javadoc command to choose the resource files of that locale for messages such as strings in the navigation bar, headings for lists and tables, help file contents, comments in the stylesheet.css file, and so on. It also specifies the sorting order for lists sorted alphabetically, and the sentence separator to determine the end of the first sentence. The -locale option doesn't determine the locale of the documentation comment text specified in the source files of the documented classes.

--module module(,module)*

Documents the specified module.

--module-path path OR -p path

Specifies where to find application modules.

The application module path (--module-path, or -mp for short) contains compiled definitions of library and application modules (all phases). At link time, this path can also contain Java SE and Java Development Kit (JDK) modules.

--module-source-path path

Specifies where to find input source files for multiple modules. The --module-source-path option contains module definitions in source form (compile time only).

-package

Shows only package, protected, and public classes and members.

--patch-module module=file(file*)

Overrides arguments in a module with classes and resources in JAR files or directories.

Note:

file(:file)* is the same as path in other options, such as --module-path, or --module-source-path.

-private

Shows all classes and members.

-protected

Shows only protected and public classes and members. This is the default.

-public

Shows only public classes and members.

-quiet

Shuts off messages so that only the warnings and errors appear to make them easier to view. It also suppresses the version string.

--release release

Provides source compatibility with a specified release.

--show-members value

Specifies which members (fields or methods) are documented, where value can be one of the following:

protected: Shows public and protected declarations. This is the default.
public: Shows only public values.
package: Shows public, protected, and package declarations.
private: Shows all declarations.

--show-module-contents value

Specifies the documentation granularity of module declarations. Possible values are api or all.

--show-packages value

Specifies which modules packages are documented. Possible values are exported or all packages.

--show-types value

Specifies which declarations (fields or methods) are documented, where value can be one of the following:

protected: Shows public and protected declarations. This is the default.
public: Shows only public values.
package: Shows public, protected, and package declarations.
private: Shows all declarations.

-source release

Specifies the release of source code accepted. Use the value of release that corresponds to the value used when you compile code with the javac command. The oldest of the releases is JDK 6 and the latest is JDK 9.

--source-path path OR -sourcepath path

Specifies the search paths for finding source files when passing package names or the -subpackages option into the javadoc command.

Oracle Solaris, Linux, and macOS: To separate multiple paths, use a colon (:).

Windows: To separate multiple paths, use a semicolon (;).

The javadoc command searches all subdirectories of the specified paths. Note that this option isn't only used to locate the source files being documented, but also to find source files that are not being documented, but whose comments are inherited by the source files being documented.

You can use the -sourcepath option only when passing package names into the javadoc command. This doesn't locate source files passed into the javadoc command. To locate source files, change to that directory or include the path ahead of each file. If you omit -sourcepath, then the javadoc command uses the class path to find the source files (see -classpath). The default -sourcepath is the value of the class path. If -classpath is omitted and you pass package names into the javadoc command, then the javadoc command searches in the current directory and subdirectories for the source files.

Set sourcepathlist to the root directory of the source tree for the package you’re documenting.

Oracle Solaris, Linux, and macOS:

For example, suppose you want to document a package called com.mypackage, whose source files are located at /home/user/src/com/mypackage/*.java. Specify sourcepath as /home/user/src, the directory that contains com\mypackage, and then supply the package name, as follows:
```
javadoc -sourcepath /home/user/src/ com.mypackage
```
Notice that if you concatenate the value of sourcepath and the package name together and change the dot to a slash (/), then you have the full path to the package:
```
/home/user/src/com/mypackage
```

To point to two source paths:

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

Windows:

For example, suppose you want to document a package called com.mypackage, whose source files are located at \user\src\com\mypackage\*.java. Specify sourcepath as \user\src, the directory that contains com\mypackage, and then supply the package name as follows:
```
javadoc -sourcepath C:\user\src com.mypackage
```
Notice that if you concatenate the value of sourcepath and the package name together and change the dot to a backslash (\), then you have the full path to the package:
```
\user\src\com\mypackage
```

To point to two source paths:

javadoc -sourcepath \user1\src;\user2\src com.mypackage

-subpackages subpkglist

Generates documentation from source files in the specified packages and recursively in their subpackages. This option is useful when adding new subpackages to the source code because they're automatically included. Each package argument is any top-level subpackage (such as java) or fully qualified package (such as javax.swing) that doesn't need to contain source files. Arguments are separated by colons on all operating systems. Wild cards aren't allowed. Use -sourcepath to specify where to find the packages. This option doesn't process source files that are in the source tree but don't belong to the packages.

For example, the following commands generates documentation for packages named java and javax.swing and all of their subpackages.

Oracle Solaris, Linux, and macOS:

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

Windows:

javadoc -d docs -sourcepath \user\src -subpackages java:javax.swing

--system jdk

Overrides ___location of the system modules used for modular releases.

The system modules are the compiled modules built in to the environment (compile time and runtime). In the case of a custom-linked image, you can also include library and application modules. At compile time, the system modules can be overridden using the -system option, which specifies a JDK image from which to load system modules.

The module definitions present on these paths (for example, --module-source-path path), together with the system modules, define the number of observable modules. A module path is a sequence, each element of which is either a module definition or a directory containing module definitions.

--upgrade-module-path path

Overrides the ___location of upgradable options. The --upgrade-module-path option contains compiled definitions of modules intended to be used in place of upgradable modules built in to the environment (compile time and runtime).

-verbose

Provides more detailed messages while the javadoc command runs. Without the verbose option, messages appear for loading the source files, generating the documentation (one message per source file), and sorting. The verbose option causes the printing of additional messages that specify the number of milliseconds to parse each Java source file.

—X

Prints a synopsis of non standard options and exit.

-Xmaxerrs number

Sets the maximum number of errors to print.

-Xmaxwarns number

Sets the maximum number of warnings to print.

-Xold

Calls the legacy javadoc tool.

-javafx

Generates HTML documentation using the JavaFX extensions to the Standard Doclet. The generated documentation includes a Property Summary section in addition to the other summary sections generated by the standard Java doclet. The listed properties are linked to the sections for the getter and setter methods of each property.

If there are no documentation comments written explicitly for getter and setter methods, then the documentation comments from the property method are automatically copied to the generated documentation for these methods. This option also adds a new @defaultValue tag that allows documenting the default value for a property.

Example:

javadoc -javafx MyClass.java -d testdir

Using the link Option

You use -link option to classes referenced to by your code, but not documented in the current javadoc command run.

For links to go to valid pages, you must know where those HTML pages are located and specify that ___location with the extdocURL option. This allows third-party documentation to link to Java. Omit the -link option when you want the javadoc command to create links only to APIs within the documentation it's generating in the current run. Without the -link option, the javadoc command doesn't create links to documentation for external references because it doesn't know whether or where that documentation exists. The -link option can create links in several places in the generated documentation. See Javadoc Doclets. Another use is for cross-links between sets of packages: Execute the javadoc command on one set of packages, then run the javadoc command again on another set of packages, creating links both ways between both sets.

Differences Between the -link and -linkoffline Options

Use the -link option in the following cases:

When you use a relative path to the external API document.
When you use an absolute URL to the external API document if your shell lets you open a connection to that URL for reading.

Use the -linkoffline option when you use an absolute URL to the external API document, if your shell doesn't allow a program to open a connection to that URL for reading. This can occur when you're behind a firewall and the document you want to link to is on the other side.

Example 3-1 Example of Using an Absolute Link to External Documents

Use the following command if you want to link to the java.lang, java.io and other Java platform packages.

javadoc -link http://docs.oracle.com/javase/8/docs/api/com.mypackage

The command generates documentation for the package com.mypackage with links to the Java SE packages. The generated documentation contains links to the Object class, for example, in the class trees. Other options, such as the -sourcepath and -d options, aren't shown.

Example 3-2 Example of Using a Relative Link to External Documents

In this example, there are two packages with documents that are generated in different runs of the javadoc command, and those documents are separated by a relative path.
The packages are com.apipackage, an API, and com.spipackage, a service provider Interface (SPI).
You want the documentation to reside in docs/api/com/apipackage and docs/spi/com/spipackage.
Assuming that the API package documentation is already generated, and that docs is the current directory, you document the SPI package with links to the API documentation by running: javadoc -d ./spi -link ../api com.spipackage.

Note:
The -link option is relative to the destination directory (docs/spi).

How to Reference a Class

For a link to an externally referenced class to appear (and not just its text label), the class must be referenced in a particular way. It isn't sufficient for the class to be referenced in the body of a method. It must be referenced in either of the following:import statement or in a declaration.

In any kind of import statement. By wildcard import, import explicitly by name, or automatically import for java.lang.*.
In a declaration: void mymethod(File f) {}.

The reference can be in the return type or parameter type of a method, constructor, field, class, or interface, or in an implements, extends, or throws statement.

When you use the -link option, there can be many links that unintentionally don't appear. The text would appear without being a link. You can detect such text by the warnings they emit. The simplest way to properly reference a class and add the link is to import that class.

In a declaration: void mymethod(File f) {}

Package List

The -link option requires that a file named package-list, which is generated by the javadoc command, exists at the URL that you specify with the -link option. In JDK 8, the package-list file is a simple text file that lists the names of packages documented at that ___location.

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

For there to be no broken links, all of the documentation for the external references must exist at the specified URLs. The javadoc command does not check that these pages exist, but only that the package-list exists.

Multiple Links

You can supply multiple -link options to link to any number of externally generated documents. 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 Linking

Note:

Bootstrapping might be required when cross-linking two or more documents that were previously generated. If the package-list file doesn't exist for either document when you run the javadoc command on the first document, then the package-list doesn't yet exist for the second document. Therefore, to create the external links, you must regenerate the first document after you generate the second document.

In this case, the purpose of first generating a document is to create its package-list (or you can create it by hand if you are certain of the package names). Then, generate the second document with its external links. The javadoc command prints a warning when a needed external package-list file doesn't exist.

Using the linkoffline Option

You use linkoffline option to link to the java.lang, java.io and other Java SE packages

Absolute Links to External Documents

You might have a situation where you want to link to the java.lang, java.io and other Java SE packages. However, your shell doesn't have web access. In this case, do the following:

Open the package-list file in a browser at API Specification.
Save the file to a local directory, and point to this local copy with the second argument, packagelistLoc. In this example, the package list file was saved to the current directory.

The following command generates documentation for the package com.mypackage with links to the Java SE packages. The generated documentation contains links to the Object class, for example, in the class trees. Other necessary options, such as -sourcepath, aren't shown.

javadoc -linkoffline http://docs.oracle.com/javase/8/docs/api/.com.mypackage

Relative Links to External Documents

It's not very common to use -linkoffline with relative paths, for the simple reason that the -link option is usually enough. When you use the -linkoffline option, the package-list file is usually local, and when you use relative links, the file you're linking to is also local, so it's usually unnecessary to give a different path for the two arguments to the -linkoffline option. When the two arguments are identical, you can use the -link option.

Create a package-list File Manually

If a package-list file doesn't exist yet, but you know what package names your document will link to, then you can manually create your own copy of this file and specify its path with packagelistLoc. An example would be where the package-list file for com.spipackage didn't exist when com.apipackage package 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 isn't yet published. Similarly, two companies can share their unpublished package-list files so they can release their cross-linked documentation simultaneously.

Link to Multiple Documents

You can include the -linkoffline option once for each generated document that you want to refer to:

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

Update Documents

You can also use the -linkoffline option when your project has dozens or hundreds of packages. If you've already run the javadoc command on the entire source tree, then you can quickly make small changes to documentation comments and rerun the javadoc command on a portion of the source tree. Be aware that the second run works properly only when your changes are to documentation comments and not to declarations. If you were to add, remove, or change any declarations from the source code, then broken links could show up in the index, package tree, inherited member lists, Use page, and other places.

First, create a new destination directory, such as update, for this new small run. In this example, the original destination directory is named html. In the simplest example, change the directory to the parent of html. Set the first argument of the -linkoffline option to the current directory and set the second argument to the relative path to html, where it can find the package-list file and pass in only the package names of the packages that you want to update:

javadoc -d update -linkoffline . html com.mypackage

Oracle Solaris, Linux, and macOS: When the javadoc command completes, copy these generated class pages in update/com/package (not the overview or index) to the original files in the html/com/package.

Windows: When the javadoc command completes, copy these generated class pages in update\com\package (not the overview or index) to the original files in html\com\package.

Using the Tag Option

Use Xaoptcmf arguments to determine where in the source code the tag is allowed to be placed, and whether the tag can be disabled (using X).

Placement of Tags

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)
s (modules)

Examples of Single Tags

An example of a tag option for a tag that can be used anywhere in the source code is: -tag todo:a:"To Do:".

If you want the @todo tag to be used only with constructors, methods, and fields, then you use: -tag todo:cmf:"To Do:".

Notice the last colon (:) isn't a parameter separator, but is part of the heading text. You can use either tag option for source code that contains the @todo tag, such as: @todo The documentation for this method needs work.

Colons in Tag Names

Use a backslash to escape a colon that you want to use in a tag name. Use the -tag ejb\\:bean:a:"EJB Bean:" option for the following documentation comment:

/**
 * @ejb:bean
 */

Spell-Checking Tag Names

Some developers put custom tags in the source code that they don't always want to produce as output. In these cases, it's important to list all tags that are 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 command enough information to know whether a tag it encounters is unknown, which is probably the results of a typographical error or a misspelling. The javadoc command prints a warning in these cases. You can add X to the placement values already present, so that when you want to enable the tag, you can simply delete the X. For example, if the @todo tag is a tag that you want to suppress on output, then you would use: -tag todo:Xcmf:"To Do:". If you would rather keep it simple, then use this: -tag todo:X. The syntax -tag todo:X works even when the @todo tag is defined by a taglet.

Order of Tags

The order of the -tag and -taglet options determines the order that the tags are produced. 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 can't be altered. For example, if the -tag option is missing, then the position of the -taglet option determines its order. If they're both present, then whichever appears last on the command line determines its order. This happens because the tags and taglets are processed in the order that they appear on the command line. For example, if the -taglet and -tag options have the name todo value, then the one that appears last on the command line determines the order.

Example of a Complete Set of Tags

This example inserts To Do after Parameters and before Throws in the output. By using X, it also specifies that the @example tag might be encountered in the source code that shouldn't be displayed during this run. If you use @argfile on the command line to specify a file containing options, then you can put the tags on separate lines in an argument file similar to this (no line continuation characters needed):

-tag param
-tag return
-tag todo:a:"To Do:"
-tag throws
-tag see
-tag example:X

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

The standard tags are initially stored internally in a list in their default order. Whenever the -tag options are used, those tags get appended to this list. Standard tags are moved from their default position. Therefore, if a -tag option is omitted for a standard tag, then it remains in its default position.

Avoiding Conflicts

If you want to create your own namespace, then you can use a dot-separated naming convention similar to that used for packages: com.mycompany.todo. Oracle continues to create standard tags whose names don't contain dots. Any tag that you create overrides the behavior of a tag by the same name defined by Oracle. If you create a @todo tag or taglet, then it always has the same behavior that you define, even when Oracle later creates a standard tag of the same name.

Annotations Versus Javadoc Tags

In general, if the markup that you want to add is intended to affect or produce documentation, then it should be a Javadoc tag. Otherwise, it should be an annotation. See Custom Tags and Annotations in How to Write Doc Comments for the Javadoc Tool.

You can also create more complex block tags or custom inline tags with the -taglet option.

javadoc Command-Line Argument Files

To shorten or simplify the javadoc command, you specify one or more files that contain arguments to the javadoc command (except -J options). This lets you to create javadoc commands of any length on any operating system.

When you run the javadoc command, pass the path and name of each argument file with the @ leading character. When the javadoc command encounters an argument beginning with the @ character, it expands the contents of that file into the argument list.

Examples

Single Argument File

You can use a single argument file named argfile to hold all javadoc command arguments: javadoc @argfile.

Two Argument Files

The argument file contains the contents of both files. You can create two argument files: One for the javadoc command options and the other for the package names or source file names. Notice the following lists have no line-continuation characters.

Create a file named options that contains:

Oracle Solaris, Linux, and macOS:

-d docs-filelist 
-use 
-splitindex
-windowtitle 'Javadoc'
-doctitle 'Javadoc Guide'
-header '<b>Java™ SE </b>'
-bottom 'Copyright &copy; 1993-2011 Oracle and/or its affiliates. All rights reserved.'
-group "Core Packages" "java.*"
-overview /java/jdk9/docs/api/overview-summary
-sourcepath /java/

Windows:

-d docs-filelist 
-use 
-splitindex
-windowtitle 'Javadoc'
-doctitle 'Javadoc Guide'
-header '<b>Java™ SE 7</b>'
-bottom 'Copyright &copy; 1993-2011 Oracle and/or its affiliates. All rights reserved.'
-group "Core Packages" "java.*"
-overview \java\jdk9\docs\api\overview-summary.html
-sourcepath \java\

Create a file named packages that contains:

com.mypackage1
com.mypackage2
com.mypackage3

Run the javadoc command as follows:

javadoc @options @packages

Argument Files with Paths

The argument files can have paths, but any file names inside the files are relative to the current working directory (not path1 or path2):

Oracle Solaris, Linux, and macOS:

javadoc @path1/options @path2/packages

Windows:

javadoc @path1\options @path2\packages

Option Arguments

The following example saves an argument to a javadoc command option in an argument file. The -bottom option is used because it can have a lengthy argument. You can create a file named bottom to contain the text argument:

<font size="-1">
    <a href="http://bugreport.java.com/bugreport/">Submit a bug or feature</a> </font>

Run the javadoc command as follows: javadoc -bottom @bottom @packages.

You can also include the -bottom option at the start of the argument file and run the javadoc command as follows: javadoc @bottom @packages.

The Standard Doclet

The Standard Doclet is the doclet provided by Oracle that produces Javadoc's default HTML-formatted API output.

This topic contains the following sections:

Javadoc Standard Doclet

Javadoc uses the Standard Doclet if no other doclet is specified using the Javadoc's -doclet option on the command line. In JDK 9, the Doclet API has been updated to use newer, more powerful APIs, that can better represent all the recent new language features. The Standard Doclet is updated to use this Doclet API.

The Standard Doclet is the doclet provided by Oracle that produces Javadoc's default HTML-formatted API output. The API Specification for the Java platform in this JDK documentation is an example of the Standard Doclet's output.

Standard Doclet Options

-author

Includes the @author text in the generated documents.

-bottom text

Specifies the text to be placed at the bottom of each output file. The text is placed at the bottom of the page, underneath the lower navigation bar. The text can contain HTML tags and white space, but when it does, the text must be enclosed in quotation marks. Use escape characters for any internal quotation marks within text.

-charset name

Specifies the HTML character set for this document. The name should be a preferred Multipurpose Internet Mail Extensions (MIME) name as specified in the IANA Registry, Character Sets.

For example, javadoc -charset "iso-8859-1" mypackage inserts the following line in the head of every generated page:

<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

This META tag is described in the HTML standard (4197265 and 4137321), HTML Document Representation.

-d directory

Specifies the destination directory where the javadoc command saves the generated HTML files. If you omit the -d option, then the files are saved to the current directory. The directory value can be absolute or relative to the current working directory. The destination directory is automatically created when the javadoc command runs.

Oracle Solaris, Linux, and OS X: For example, the following command generates the documentation for the package com.mypackage and saves the results in the /user/doc/ directory:

javadoc -d /user/doc/ com.mypackage

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

javadoc -d \user\doc\ com.mypackage

-docencoding name

Specifies the encoding of the generated HTML files. The name should be a preferred MIME name as specified in the IANA Registry, Character Sets.

If you omit the -docencoding option but use the -encoding option, then the encoding of the generated HTML files is determined by the -encoding option, for example: javadoc -docencoding "iso-8859-1" mypackage.

-docfilessubdirs

Recursively copies doc-file subdirectories

-doctitle title

Specifies the title to place near the top of the overview summary file. The text specified in the title tag is placed as a centered, level-one heading directly beneath the top navigation bar. The title tag can contain HTML tags and white space, but when it does, you must enclose the title in quotation marks. Internal quotation marks within the title tag must be escaped. For example, javadoc -header "Java Library v8" com.mypackage.

--excludedocfilessubdir name

Excludes any doc-file subdirectories with the given name. This option enables deep copying of doc-files directories. Subdirectories and all contents are recursively copied to the destination. For example, the directory doc-files/example/images and all of its contents are copied. There's also an option to exclude subdirectories.

-footer html-code

Specifies the footer text to be placed at the bottom of each output file. Thehtml-code value is placed to the right of the lower navigation bar. The html-code value can contain HTML tags and white space, but when it does, the html-code value must be enclosed in quotation marks. Use escape characters for any internal quotation marks within a footer.

--frames

Enables the use of frames in the generated output (default).

-group name p1:p2

Groups specified packages together in overview page.

The -group groupheading packagepattern:packagepattern separates packages on the overview page into whatever groups you specify, one group per table. You specify each group with a different -group option. The groups appear on the page in the order specified on the command line. Packages are alphabetized within a group. For a specified -group option, the packages matching the list of packagepattern expressions appear in a table with the heading groupheading.

The groupheading value can be any text and can include white space. This text is placed in the table heading for the group.
The packagepattern value can be any package name at the start of any package name followed by an asterisk (*). The asterisk is the only wildcard allowed and means match any characters. Multiple patterns can be included in a group by separating them with colons (:). If you use an asterisk in a pattern or pattern list, then the pattern list must be inside quotation marks, such as "java.lang*:java.util".

When you don't supply a -group option, all packages are placed in one group with the heading Packages and appropriate subheadings. If the subheadings don't include all documented packages (all groups), then the remaining packages appear in a separate group with the subheading Other Packages.

For example, the following javadoc command separates the three documented packages into Core, Extension, and Other Packages. The trailing dot (.) doesn't appear in java.lang*. Including the dot, such as java.lang.* omits 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

Core Packages

java.lang

java.lang.reflect

java.util

Extension Packages

javax.servlet

Other Packages

java.new

-header header

Specifies the header text to be placed at the top of each output file. The header is placed to the right of the upper navigation bar. The header option can contain HTML tags and white space, but when it does, the header text must be enclosed in quotation marks. Use escape characters for internal quotation marks within a header. For example, javadoc -header "Java Platform v8" com.mypackage.

-helpfile path\filename

Specifies the path of an alternate help file path\filename that the HELP link in the top and bottom navigation bars link to. Without this option, the javadoc command creates a help-doc.html help file that is hard-coded in the javadoc command. This option lets you override the default. The file name can be any name and isn't restricted to help-doc.html. The javadoc command adjusts the links in the navigation bar accordingly, for example:

Oracle Solaris, Linux, and macOS:

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

Windows:

javadoc -helpfile C:\user\myhelp.html java.awt.

-html4

Generates HTML4.0.1 output.

-html5

Generates HTML5 output. HTML5 increases the semantic value of web pages and makes it easier to create accessible web pages.

Note:

For both -html4 and -html5; These options assume that the HTML in the document comments is of the same version (4 or 5). If you don't specify any of these options, then, by default HTML4 output is generated. The standard doclet doesn't convert the HTML in the user documentation comments to the specified output version.

-keywords

Adds HTML keyword <META> tags to the generated file for each class. These tags can help search engines that look for <META> tags find the pages. Most search engines that search the entire internet don't look at <META> tags, because pages can misuse them. Search engines offered by companies that confine their searches to their own website can benefit by looking at <META> tags. The <META> tags include the fully qualified name of the class and the unqualified names of the fields and methods. Constructors aren't 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()">

-link URL

Creates links to existing Javadoc-generated documentation of externally referenced classes. The extdocURL argument is the absolute or relative URL of the directory that contains the external Javadoc-generated documentation you want to link to. You can specify multiple -link options in a specified javadoc command run to link to multiple documents.

The package-list file must be found in this directory (otherwise, use the -linkoffline option). The javadoc command reads the package names from the package-list file and links to those packages at that URL. When the javadoc command runs, the extdocURL value is copied into the <A HREF> links that are created. Therefore, extdocURL must be the URL to the directory, and not to a file. You can use an absolute link for extdocURL to enable your documents to link to a document on any website, or you can use a relative link to link only to a relative ___location. If you use a relative link, then the value that you pass in should be the relative path from the destination directory (specified with the -d option) to the directory containing the packages being linked to. When you specify an absolute link, you usually use an HTTP link. However, if you want to link to a file system that has no web server, then you can use a file link. Use a file link only when everyone who wants to access the generated documentation shares the same file system. In all cases, and on all operating systems, use a slash as the separator, whether the URL is absolute or relative, and http: or file: as specified in the URL Memo: Uniform Resource Locators.

-link  http://<host>/<directory>/<directory>/.../<name>
-link file://<host>/<directory>/<directory>/.../<name>
-link <directory>/<directory>/.../<name>

See Using the link Option.

-linkoffline url1 url2

Offers a variation of the -link option. They both create links to Javadoc-generated documentation for externally referenced classes. Use the -linkoffline option when linking to a document on the web when the javadoc command can't access the document through a web connection. Use the -linkoffline option when the package-list file of the external document isn't accessible or doesn't exist at the url ___location, but does exist at a different ___location that can be specified by packageListLoc (typically local). If url1 is accessible only on the World Wide Web, then the -linkoffline option removes the constraint that the javadoc command must have a web connection to generate documentation. Another use is as a workaround to update documents: After you've run the javadoc command on a full set of packages, you can run the javadoc command again on a smaller set of changed packages, so that the updated files can be inserted back into the original set. The -linkoffline option takes two arguments. The first is for the string to be embedded in the <a href> links, and the second tells the -linkoffline option where to find the package-list file:

The url1 or url2 value is the absolute or relative URL of the directory that contains the external Javadoc-generated documentation that you want to link to. When relative, the value should be the relative path from the destination directory (specified with the -d option) to the root of the packages being linked to. See url in the -link option. You can specify multiple -linkoffline options in a specified javadoc command run.

See Using the linkoffline Option.

-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 aren't created, such as for default constructors and generated classes.

This option exposes all private implementation details in the included source files, including private classes, private fields, and the bodies of private methods, regardless of the -public, -package, -protected, and -private options. Unless you also use the -private option, not all private classes or interfaces are accessible through links.

Each link appears on the name of the identifier in its declaration. For example, the link to the source code of the Button class is on the word Button:

public class Button extends Component implements Accessible

The link to the source code of the getLabel method in the Button class is on the word getLabel:

public String getLabel()

-nocomment

Suppresses the entire comment body, including the main description and all tags, and generates only declarations. This option lets you reuse source files that were originally intended for a different purpose so that you can produce skeleton HTML documentation at the early stages of a new project.

-nodeprecated

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

-nodeprecatedlist

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

--no-frames

Disables the use of frames in the generated output.

-nohelp

Omits the HELP link in the navigation bars at the top and bottom of each page of output.

-noindex

Omits the index from the generated documents. The index is produced by default.

-nonavbar

Prevents the generation of the navigation bar, header, and footer, that are usually found at the top and bottom of the generated pages. The -nonavbar option has no effect on the -bottom option. The -nonavbar option is useful when you're interested only in the content and have no need for navigation, such as when you're converting the files to PostScript or PDF for printing only.

-noqualifier all |packagename1:packagename2...

Omits qualifying package names from class names in output. The argument to the -noqualifier option is either all (all package qualifiers are omitted) or a colon-separated list of packages, with wild cards, 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 previous behavior, the name can be suitably shortened. This rule is in effect whether or not the -noqualifier option is used.

-nosince

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

-notimestamp

Suppresses the time stamp, which is hidden in an HTML comment in the generated HTML near the top of each page. The -notimestamp option is useful when you want to run the javadoc command on two source bases and get the differences between them by using diff , because it prevents time stamps from causing a different occurrencediff (which would otherwise be a diff on every page). The time stamp includes the javadoc command release number, and currently appears similar to this: .

-notree

Omits the class/interface hierarchy pages from the generated documents. These are the pages that you reach using the Tree button in the navigation bar. The hierarchy is produced by default.

-overview filename

Specifies that the javadoc command should retrieve the text for the overview documentation from the source file specified byfilename and place it on the overview page (overview-summary.html). A relative path specified with the file name is relative to the current working directory.

While you can use any name that you want for the filename value and place it anywhere that you want for the path, it's typical to name it overview.html and place it in the source tree at the directory that contains the topmost package directories. In this ___location, no path is needed when documenting packages, because the -sourcepath option points to this file.

Oracle Solaris, Linux, and macOS: 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.

Windows: 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 Examples of Running the javadoc Command.

For information about the file specified by filename, see Overview Comment Files in Source Files.

The overview page is created only when you pass two or more package names to the javadoc command. For a further explanation, see HTML Frames in Generated Files. The title on the overview page is set by -doctitle.

-serialwarn

Generates compile-time warnings for missing @serial tags. Use this option to display the serial warnings, which helps to properly document default serializable fields and writeExternal methods.

-sourcetab tablength

Specifies the number of spaces each tab uses in the source.

-splitindex

Splits the index file into multiple files, alphabetically, one file per letter, plus a file for any index entries that start with non-alphabetical symbols.

-stylesheet filename

Specifies the path of an alternate HTML stylesheet file. Without this option, the javadoc command automatically creates a stylesheet file stylesheet.css that's coded in the javadoc command. This option lets you override the default. The file name can be any name and isn't restricted to stylesheet.css, for example:

Oracle Solaris, Linux, and macOS:

javadoc -stylesheet file /home/user/mystylesheet.css com.mypackage

Windows:

javadoc -stylesheet file C:\user\mystylesheet.css com.mypackage

-tag tagname :Xaoptcmf:"taghead"

Enables the javadoc command to interpret a simple, one-argument @tagname custom block tag in documentation comments. For the javadoc command to spell-check tag names, it's important to include a -tag option for every custom tag that's present in the source code, disabling (with X) those that aren't being displayed in the current run. The colon (:) is always the separator. The -tag option produces the tag heading taghead in bold, followed on the next line by the text from its single argument. Similar to any block tag, the argument text can contain inline tags, which are also interpreted. The output is similar to standard one-argument tags, such as the @return and @author tags. Omitting a value for taghead causes tagname to be the heading.

See Using the Tag Option.

-taglet class

Specifies the class file that starts the taglet used in generating the documentation for that tag. Use the fully qualified name for the class value. This taglet also defines the number of text arguments that the custom tag has. The taglet accepts those arguments, processes them, and generates the output.

Taglets are useful for block or inline tags. They can have any number of arguments and implement custom behavior, such as making text bold, formatting bullets, writing out the text to a file, or starting other processes. Taglets can only determine where a tag should appear and in what form. All other decisions are made by the doclet. A taglet can't do things such as remove a class name from the list of included classes. However, it can execute side effects, such as printing the tag's text to a file or triggering another process. Use the -tagletpath option to specify the path to the taglet. The following example inserts the To Do taglet after Parameters and ahead of Throws in the generated pages:

-taglet com.sun.tools.doclets.ToDoTaglet
-tagletpath /home/taglets 
-tag return
-tag param
-tag todo
-tag throws
-tag see

Alternately, you can use the -taglet option in place of its -tag option, but that might be difficult to read.

-tagletpath tagletpathlist

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

-top

Specifies the text to be placed at the top of each output file.

-use

Includes one Use page for each documented class and package. The page describes what packages, classes, methods, constructors, and fields use any API of the specified class or package. Given class C, things that use class C includes subclasses of C, fields declared as C, methods that return C, and methods and constructors with parameters of type C. For example, you can look at the Use page for the String type. Because the getName method in the java.awt.Font class returns type String, the getName method uses String and so the getName method appears on the Use page for String. This documents uses of only the API, not the implementation. When a method uses String in its implementation, but doesn't take a string as an argument or return a string, that isn't considered a use of String. To access the generated Use page, go to the class or package and click the Use link in the navigation bar.

-version

Includes the @version text in the generated documents. This text is omitted by default. To find out what version of the javadoc command you're using, use the -J-version option.

-windowtitle title

Specifies the title to be placed in the HTML <title> tag. The text specified in the title tag appears in the window title and in any browser bookmarks (favorite places) that someone creates for this page. This title shouldn't contain any HTML tags because the browser doesn't interpret them correctly. Use escape characters on any internal quotation marks within the title tag. If the -windowtitle option is omitted, then the javadoc command uses the value of the -doctitle option for the -windowtitle option. For example, javadoc -windowtitle "Java Library" com.mypackage.

-Xdoclint

Enables recommended checks for problems in javadoc comments.

-Xdoclint:(all|none|[-] group) )

Reports warnings for bad references, lack of accessibility and missing javadoc comments, and reports errors for invalid Javadoc syntax and missing HTML tags.

This option enables the javadoc command to check for all documentation comments included in the generated output. As always, you can select which items to include in the generated output with the standard options -public, -protected, -package and -private.

When the -Xdoclint is enabled, it reports issues with messages similar to the javac command. The javadoc command prints a message, a copy of the source line, and a caret pointing at the exact position where the error was detected. Messages may be either warnings or errors, depending on their severity and the likelihood to cause an error if the generated documentation were run through a validator. For example, bad references or missing javadoc comments don't cause the javadoc command to generate invalid HTML, so these issues are reported as warnings. Syntax errors or missing HTML end tags cause the javadoc command to generate invalid output, so these issues are reported as errors.

-Xdoclint option validates input comments based upon the requested markup.

By default, the -Xdoclint option is enabled. Disable it with the option -Xdoclint:none.

Change what the -Xdoclint option reports with the following options:

-Xdoclint none: Disables the -Xdoclint option.
-Xdoclint group: Enables group checks.
-Xdoclint all: Enables all groups of checks.
-Xdoclint all, -group: Enables all checks except group checks.

The variable group has one of the following values:

accessibility: Checks for the issues to be detected by an accessibility checker (for example, no caption or summary attributes specified in a <table> tag).
html: Detects high-level HTML issues, such as putting block elements inside inline elements, or not closing elements that require an end tag. The rules are derived from the HTML4 Specification and HTML5 Specification based on the standard doclet html output generation selected. This type of check enables the javadoc command to detect HTML issues that some browsers might not interpret as intended.
missing: Checks for missing javadoc comments or tags (for example, a missing comment or class, or a missing @return tag or similar tag on a method).
reference: Checks for issues relating to the references to Java API elements from javadoc tags (for example, item not found in @see , or a bad name after @param).
syntax: Checks for low level issues like unescaped angle brackets (< and >) and ampersands (&) and invalid javadoc tags.

You can specify the -Xdoclint option multiple times to enable the option to check errors and warnings in multiple categories. Alternatively, you can specify multiple error and warning categories by using the preceding options. For example, use either of the following commands to check for the HTML, syntax, and accessibility issues in the file filename:

javadoc -Xdoclint:html -Xdoclint:syntax -Xdoclint:accessibility filename
javadoc -Xdoclint:html,syntax,accessibility filename

Note:

The javadoc command doesn't guarantee the completeness of these checks. In particular, it isn't a full HTML compliance checker. The goal of the -Xdoclint option is to enable the javadoc command to report the majority of common errors.

The javadoc command doesn't attempt to fix invalid input, it just reports it.

--Xdoclint/package:([-])packages

Enables or disables checks in specific packages. packages is a comma-separated list of package specifiers. A package specifier is either a qualified name of a package or a package name prefix followed by *, which expands to all subpackages of the given package. Prefix the package specifier with - to disable checks for the specified packages.

-Xdocrootparent url

Replaces all @docRoot followed by /.. in any doc comments with url.

Generated Files

You use the javadoc command as a Standard Doclet that generates HTML-formatted documentation.

The Standard Doclet generates the basic content, cross-reference, and support pages. Each HTML page corresponds to a separate file. The javadoc command generates two types of files. The first type is named after classes and interfaces. The second type contains hyphens (such as package-summary.html) to prevent conflicts with the first type of file.

Basic Content Pages

One class or interface page (classname.html) for each class or interface being documented.
One package page (package-summary.html) for each package being documented. The javadoc command includes any HTML text provided in a file with the name package.html or package-info.java in the package directory of the source tree.
One overview page (overview-summary.html) for the entire set of packages. The overview page is the front page of the generated document. The javadoc command includes any HTML text provided in a file specified by the -overview option. The overview page is created only when you pass two or more package names into the javadoc command. See HTML Frames and Javadoc Doclet Options.

Cross-Reference Pages

One class hierarchy page for the entire set of packages (overview-tree.html). To view the hierarchy page, click Overview in the navigation bar and click Tree.
One class hierarchy page for each package (package-tree.html). To view the hierarchy page, go to a particular package, class, or interface page, and click Tree to display the hierarchy for that package.
One Use page for each package (package-use.html) and a separate Use page for each class and interface (class-use/classname.html). The Use page describes what packages, classes, methods, constructors and fields use any part of the specified class, interface, or package. For example, given a class or interface A, its Use page includes subclasses of A, fields declared as A, methods that return A, and methods and constructors with parameters of type A. To view the Use page, go to the package, class, or interface and click the Use link in the navigation bar.
A deprecated API page (deprecated-list.html) that lists all deprecated APIs and their suggested replacements. Avoid deprecated APIs because they can be removed in future implementations.

A constant field values page (constant-values.html) for the values of static fields.
A serialized form page (serialized-form.html) that provides information about serializable and externalizable classes with field and method descriptions. The information on this page is of interest to reimplementors, and not to developers who want to use the API. To access the serialized form page, go to any serialized class and click Serialized Form in the See Also section of the class comment. The Standard Doclet generates a serialized form page that lists any class (public or non-public) that implements Serializable with its readObject and writeObject methods, the fields that are serialized, and the documentation comments from the @serial, @serialField, and @serialData tags. Public Serializable classes can be excluded by marking them (or their package) with @serial exclude , and package-private Serializable classes can be included by marking them (or their package) with an @serial include . You can generate the complete serialized form for public and private classes by running the javadoc command without specifying the -private option. See Javadoc Doclet Options.
An index page (index-*.html) of all class, interface, constructor, field and method names, in alphabetical order. The index page is internationalized for Unicode and can be generated as a single file or as a separate file for each starting character (such as A–Z for English).

Support Pages

A help page (help-doc.html) that describes the navigation bar and the previous pages. Use -helpfile to override the default help file with your own custom help file.
One index.html file that creates the HTML frames for display. Load this file to display the front page with frames. The index.html file contains no text content.
Several frame files (*-frame.html) that contains lists of packages, classes, and interfaces. The frame files display the HTML frames.
A package-list file that is used by the -link and -linkoffline options. The package list file is a text file that is not reachable through links.
A style sheet file (stylesheet.css) that controls a limited amount of color, font family, font size, font style, and positioning information on the generated pages.
A doc-files directory that holds image, example, source code, or other files that you want copied to the destination directory. These files aren't processed by the javadoc command. This directory is not processed unless it exists in the source tree.

See Javadoc Doclet Options.

HTML Frames

The javadoc command generates the minimum number of frames necessary (two or three) based on the values passed to the command. It omits the list of packages when you pass a single package name or source files that belong to a single package as an argument to the javadoc command. Instead, the javadoc command creates one frame in the left-hand column that displays the list of classes. When you pass two or more package names, the javadoc command creates a third frame that lists all packages and an overview page (overview-summary.html). The HTML frames are enabled by default, but can be disabled by the --no-frames option. To bypass frames, click the No Frames link or enter the page set from the overview-summary.html page. The Javadoc Search feature provides a better way to navigate and saves screen space.

Generated File Structure

The generated class and interface files are organized in the same directory hierarchy that Java source files and class files are organized. This structure is one directory per subpackage.

Oracle Solaris, Linux, and macOS: For example, the document generated for the java.math.BigDecimal class would be located at java/math/BigDecimal.html.

Windows: For example, the document generated for the java.math.BigDecimal class would be located at java\math\BigDecimal.html.

The file structure for the java.math package follows, assuming that the destination directory is named apidocs. All files that contain the word frame appear in the upper-left or lower-left frames, as noted. All other HTML files appear in the right-hand frame.

Directories are bold. The asterisks (*) indicate the files and directories that are omitted when the arguments to the javadoc command are source file names rather than package names. When arguments are source file names, an empty package list is created. The doc-files directory isn't created in the destination unless it exists in the source tree.

Generated API Declarations

The javadoc command generates a declaration at the start of each class, interface, field, constructor, and method description for that API item. For example, the declaration for the Boolean class is:

public final class Boolean
extends Object
implements Serializable

The declaration for the Boolean.valueOf method is:

public static Boolean valueOf(String s)

The javadoc command can include the modifiers public, protected, private, abstract, final, static, transient, and volatile, but not synchronized or native. The synchronized and native modifiers are considered implementation detail and not part of the API specification.

Rather than relying on the keyword synchronized, APIs should document their concurrency semantics in the main description of the comment. For example, a description might be:

A single enumeration cannot be used by multiple threads concurrently.

The document shouldn't describe how to achieve these semantics. As another example, while the Hashtable option should be thread-safe, there is no reason to specify that it's achieved by synchronizing all of its exported methods. It’s better to reserve the right to synchronize internally for higher concurrency.

Examples of Running the javadoc Command

You can run the javadoc command on entire packages or individual source files. Use the public programmatic interface to call the javadoc command from within programs written in the Java language.

The release number of the javadoc command can be determined with the javadoc -J-version option. The release number of the Standard Doclet appears in the output stream. It can be turned off with the -quiet option.

Use the public programmatic interface in com.sun.tools.javadoc.Main (and the javadoc command is reentrant) to call the javadoc command from within programs written in the Java language.

The following instructions call the Standard HTML Doclet. To call a custom doclet, use the -doclet and -docletpath options.

Simple Examples

The following are simple examples of running the javadoc command on entire packages or individual source files. Each package name has a corresponding directory name.

Oracle Solaris, Linux, and macOS: In the following examples, the source files are located at /home/src/java/awt/*.java. The destination directory is /home/html.

Windows: In the following examples, the source files are located at C:\home\src\java\awt\*java. The destination directory is C:\home\html.

Document One or More Packages: To document a package, the source files for that package must be located in a directory that has the same name as the package.

Oracle Solaris, Linux, and macOS:

If a package name has several identifiers (separated by dots, such as java.awt.color), then each subsequent identifier must correspond to a deeper subdirectory (such as java/awt/color).
You can split the source files for a single package among two such directory trees located at different places, as long as the -sourcepath option points to them both. For example, src1/java/awt/color and src2/java/awt/color.

Windows:

If a package name has several identifiers (separated by dots, such as java.awt.color), then each subsequent identifier must correspond to a deeper subdirectory (such as java\awt\color).
You can split the source files for a single package among two such directory trees located at different places, as long as the -sourcepath option points to them both. For example, src1\java\awt\color and src2\java\awt\color.

You can run the javadoc command either by changing directories (with the cd command) or by using the -sourcepath option. The following examples illustrate both alternatives:

Example 1 Recursive Run from One or More Packages

This example uses -sourcepath so the javadoc command can be run from any directory for recursion. It traverses the subpackages of the Java directory excluding packages rooted at java.net and java.lang. Notice this excludes java.lang.ref, a subpackage of java.lang. To also traverse down other package trees, append their names to the -subpackages argument, such as java:javax:org.xml.sax.

javadoc -d /home/html -sourcepath /home/src -subpackages java -exclude

Example 2 Change to Root and Run Explicit Packages

Change to the parent directory of the fully qualified package.
Run the javadoc command with the names of one or more packages that you want to document:

Oracle Solaris, Linux, and macOS:
```
cd /home/src/
javadoc -d /home/html java.awt java.awt.event
```
Windows:
```
cd C:\home\src\
javadoc -d C:\home\html java.awt java.awt.event
```
To also traverse down other package trees, append their names to the -subpackages argument, such as java:javax:org.xml.sax.

Example 3 Run from Any Directory on Explicit Packages in One Tree

In this case, it doesn't matter what the current directory is. Run the javadoc command and use the -sourcepath option with the parent directory of the top-level package. Provide the names of one or more packages that you want to document:

Oracle Solaris, Linux, and macOS:

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

Windows:

javadoc -d C:\home\html -sourcepath C:\home\src java.awt java.awt.event

Example 4 Run from Any Directory on Explicit Packages in Multiple Trees

Run the javadoc command and use the -sourcepath option with a colon-separated list of the paths to each tree's root. Provide the names of one or more packages that you want to document. All source files for a specified package don't need to be located under a single root directory, but they must be found somewhere along the source path.

Oracle Solaris, Linux, and macOS:

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

Windows:

javadoc -d C:\home\html -sourcepath C:\home\src1;C:\home\src2 java.awt java.awt.event

The result is that all cases generate HTML-formatted documentation for the public and protected classes and interfaces in packages java.awt and java.awt.event and save the HTML files in the specified destination directory. Because two or more packages are being generated, the document has three HTML frames: one for the list of packages, another for the list of classes, and the third for the main class pages.

Document One or More Classes

The second way to run the javadoc command is to pass one or more source files. You can run javadoc either of the following two ways: by changing directories (with the cd command) or by fully specifying the path to the source files. Relative paths are relative to the current directory. The -sourcepath option is ignored when passing source files. You can use command-line wildcards, such as an asterisk (*), to specify groups of classes.

Example 1 Change to the Source Directory

Change to the directory that holds the source files. Then run the javadoc command with the names of one or more source files, you want to document.

This example generates HTML-formatted documentation for the classes Button, Canvas, and classes that begin with Graphics. Because source files rather than package names were passed in as arguments to the javadoc command, the document has two frames: one for the list of classes and the other for the main page.

Oracle Solaris, Linux, and macOS:

cd /home/src/java/awt
javadoc -d /home/html Button.java Canvas.java Graphics*.java

Windows:

cd C:\home\src\java\awt
javadoc -d C:\home\html Button.java Canvas.java Graphics*.java

Example 2 Change to the Root Directory of the Package

This is useful for documenting individual source files from different subpackages off of the same root. Change to the package root directory, and specify the source files with paths from the root.

Oracle Solaris, Linux, and macOS:

cd /home/src/
javadoc -d /home/html java/awt/Button.java java/math/BigDecimal.java

Windows:

cd C:\home\src
javadoc -d \home\html java\awt\Button.java java\math\BigDecimal.java

Example 3 Document Files from Any Directory

In this case, it doesn't matter what the current directory is. Run the javadoc command with the absolute path (or path relative to the current directory) to the source files that you want to document.

Oracle Solaris, Linux, and macOS:

javadoc -d /home/html /home/src/java/awt/Button.java \   
        /home/src/java/awt/Graphics*.java

Windows:

javadoc -d C:\home\html C:\home\src\java\awt\Button.java ^
        C:\home\src\java\awt\Graphics*.java

Document Packages and Classes

You can document entire packages and individual classes at the same time. The following is an example that mixes two of the previous examples. You can use the -sourcepath option for the path to the packages but not for the path to the individual classes.

Example 1

Oracle Solaris, Linux, and macOS:

avadoc -d /home/html -sourcepath /home/src java.awt \
        /home/src/java/math/BigDecimal.java

Example 2

Windows:

javadoc -d C:\home\html -sourcepath C:\home\src java.awt ^
        C:\home\src\java\math\BigDecimal.java

Notes

If you omit the -windowtitle option, then the javadoc command copies the document title to the window title. The -windowtitle option text is similar to the -doctitle option, but without HTML tags to prevent those tags from appearing as just characters (plain text) in the window title.
If you omit the -footer option, then the javadoc command copies the header text to the footer.
Other important options you might want to use, but weren't needed in the previous example, are the -classpath and -link options.
The javadoc command reads only files that contain valid class names. If the javadoc command isn't correctly reading the contents of a file, then verify that the class names are valid.