Javadoc - the Documentation Generator

options Specifies command-line options, separated by spaces.

packagenames 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 the packages.

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

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

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

Description

The javadoc tool parses the declarations and documentation comments in a set of Java source files and produces corresponding 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 tool to generate the API documentation, or the implementation documentation for a set of source files.

You can run the javadoc tool on entire packages, individual source files, or both. When documenting entire packages, you can use the -subpackages option either 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 checking the generated output with any appropriate conformance and other checking tools.

Options for javadoc

The following core javadoc options are equivalent to corresponding javac options. See Standard Options for the detailed descriptions of using these options:

--add-modules -bootclasspath --class-path, -classpath, or -cp --enable-preview -encoding -extdirs --limit-modules --module --module-path or -p --module-source-path --release -source --source-path or -sourcepath --system --upgrade-module-path 

The following options are the core javadoc options that are not equivalent to a corresponding javac option:

-breakiterator Computes the first sentence with BreakIterator. 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:

English default sentence-break algorithm — Stops at a period followed by a space or an HTML block tag, such as . Breakiterator sentence-break algorithm — Stops at a period, question mark, or exclamation point followed by a space when the next word starts with a capital letter. This is meant to handle most abbreviations (such as "The serial no. is valid", but will not handle "Mr. Smith"). The -breakiterator option 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 embedded in an HTML tag. 

-doclet class Generates output by using an alternate doclet. Use the fully qualified name. This doclet defines the content and formats the output. If the -doclet option isn’t used, then the javadoc tool 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.

-docletpath path Specifies where to find doclet class files (specified with the -doclet option) and any JAR files it depends on. If the starting class file is in a JAR file, then this option specifies the path to that JAR file. You can specify an absolute path or a path relative to the current directory. If classpathlist contains multiple paths or JAR files, then they should be separated with a colon ( : ) on Linux and macOS and a semi-colon ( ; ) on Windows. This option isn’t necessary when the doclet starting class is already in the search path.

-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 :

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 tool to expand the set of modules to be documented. By default, only the modules given explicitly on the command line are documented. Supports the following values:

transitive: additionally includes all the required transitive dependencies of those modules.

all: includes all dependencies.

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

--help-extra or -X Prints a synopsis of non-standard options and exits.

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

There is no space between the J and the flag.

Use the -version option to report the version of the JRE being used to run the javadoc tool:

javadoc -J-version openjdk version "16" 2021-03-16 OpenJDK Runtime Environment (build 16+36-2231) OpenJDK 64-Bit Server VM (build 16+36-2231, mixed mode, sharing) 

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

Specifying a locale causes the javadoc tool 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.

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

-private Shows all classes and members.

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

-public Shows only the 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.

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

protected: The default value is protected. public: Shows only public values. package: Shows public, protected, and package members. private: Shows all members. 

--show-module-contents value Specifies the documentation granularity of module declarations, where value can be api or all.

--show-packages value Specifies which modules packages are documented, where value can be exported or all packages.

--show-types value Specifies which types (classes, interfaces, etc.) are documented, where value can be any of the following:

protected: The default value. Shows public and protected types. public: Shows only public values. package: Shows public, protected, and package types. private: Shows all types. 

-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 are 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 generate documentation for packages named java and javax.swing and all of their subpackages:

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 

-verbose Provides more detailed messages while the javadoc tool 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.

--version Prints version information.

Extended Options

The following extended javadoc options are equivalent to corresponding javac options. See Extra Options in javac for the detailed descriptions of using these options: --add-exports

--add-reads --patch-module -Xmaxerrs -Xmaxwarns 

The following extended javadoc options are not equivalent to a corresponding javac option:

-Xmodule:module-name Specifies a module to which the classes being compiled belong.

-Xold Invokes the legacy javadoc tool.

Standard Doclet Options

The following options are provided by the standard doclet.

--add-stylesheet file Adds additional stylesheet file for the generated documentation. This option can be used one or more times to specify additional stylesheets included in the documentation.

javadoc --add-stylesheet new_stylesheet_1.css --add-stylesheet new_stylesheet_2.css pkg_foo 

--allow-script-in-comments Allow JavaScript in options and comments

-author Includes the @author text in the generated docs.

-bottom html-code 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 MIME name as specified in the IANA Registry, Character Sets.

javadoc -charset "iso-8859-1" mypackage 

This command inserts the following line in the head of every generated page:

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

-d directory Specifies the destination directory where the javadoc tool 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 tool runs.

Linux and macOS: 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.

Three options are available for use in a javadoc encoding command. The -encoding option is used for encoding the files read by the javadoc tool, while the -docencoding and -charset options are used for encoding the files written by the tool. Of the three available options, at most, only the input and an output encoding option are used in a single encoding command. If you specify both input and output encoding options in a command, they must be the same value. If you specify neither output option, the tool defaults to the input encoding.

javadoc -docencoding "iso-8859-1" mypackage 

-docfilessubdirs Recursively copies doc-file subdirectories.

-doctitle html-code 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. Additional quotation marks within the title tag must be escaped. For example, javadoc -header "My Library
v1.0" com.mypackage.

-excludedocfilessubdir name Excludes any doc files sub directories with the given name. 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 is 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 namep1:p2 Group the specified packages together in the Overview page.

-header html-code Specifies the header text to be placed at the top of each output file. The header is placed to the right of the upper navigation bar. The header can contain HTML tags and white space, but when it does, the header must be enclosed in quotation marks. Use escape characters for internal quotation marks within a header. For example, javadoc -header "My Library
v1.0" com.mypackage.

-helpfile filename Includes the file that links to the HELP link in the top and bottom navigation bars . Without this option, the javadoc tool creates a help file, help-doc.html, that is hard-coded in the javadoc tool. This option lets you override the default. The filename can be any name and isn’t restricted to help-doc.html. The javadoc tool adjusts the links in the navigation bar accordingly. For example:

Linux and macOS:

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

Windows:

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

-html4 Generates HTML 4.0.1 output. HTML 5 output is the default.

-html5 Generates HTML 5 output (default).

--javafx or -javafx Enables JavaFX functionality.

-keywords Adds HTML keyword tags to the generated file for each class. These tags can help search engines that look for tags find the pages. Most search engines that search the entire Internet don’t look at tags, because pages can misuse them. Search engines offered by companies that confine their searches to their own website can benefit by looking at tags. The 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:

-link url Creates links to existing javadoc generated documentation of externally referenced classes. The URL argument is the absolute or relative URL of the directory that contains the external javadoc generated documentation. You can specify multiple -link options in a specified javadoc tool run to link to multiple documents. Either a package-list or an element-list file must be in this url directory (otherwise, use the -linkoffline option).

When you use the javadoc tool to document packages, it uses the package-list file to determine the packages declared in an API. When you generate API documents for modules, the javadoc tool uses the element-list file to determine the modules and packages declared in an API.

The javadoc tool reads the names from the appropriate list file and then links to the packages or modules at that URL. When the javadoc tool runs, the URL value is copied into the links that are created. Therefore, url must be the URL to the directory and not to a file. You can use an absolute link for url 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 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 https:, http:, or file: as specified in the URL Memo: Uniform Resource Locators.

-link https://///. / -link http://///. / -link file://///. / -link //. / -linkoffline url1 url2 

This option is a variation of the -link option. They both create links to javadoc generated documentation for externally referenced classes. You can specify multiple -linkoffline options in a specified javadoc tool run.

Use the -linkoffline option when:

If url1 is accessible only on the World Wide Web, then the -linkoffline option removes the constraint that the javadoc tool must have a web connection to generate documentation.

Another use of the -linkoffline option is as a work-around to update documents. After you have run the javadoc tool on a full set of packages or modules, you can run the javadoc tool again on a smaller set of changed packages or modules, so that the updated files can be inserted back into the original set.

For example, the -linkoffline option takes two arguments. The first is for the string to be embedded in the links, and the second tells the javadoc tool where to find either the package-list or element-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.

-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 would be on the word Button :

public class Button extends Component implements Accessible 

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

public String getLabel() 

--main-stylesheet file or -stylesheetfile file Specifies the path of an alternate stylesheet file that contains the definitions for the CSS styles used in the generated documentation. This option lets you override the default. If you do not specify the option, the javadoc tool will create and use a default stylesheet. The file name can be any name and isn’t restricted to stylesheet.css . The --main-stylesheet option is the preferred form.

javadoc --main-stylesheet main_stylesheet.css pkg_foo 

-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 during 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 tool 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 affect on the -bottom option. The -nonavbar option is useful when you are interested only in the content and have no need for navigation, such as when you are converting the files to PostScript or PDF for printing only.

-noqualifier name1:name2. Excludes the list of qualifiers from the output. The package name is removed from places where class or interface names appear.

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 tool on two source bases and get the differences between them, because it prevents time stamps from causing a diff (which would otherwise be a diff on every page). The time stamp includes the javadoc tool release number.

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

--override-methods (detail|summary) Documents overridden methods in the detail or summary sections.

-overview filename Specifies that the javadoc tool should retrieve the text for the overview documentation from the source file specified by filename 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 you want for the filename value and place it anywhere you want for the path, it is typical to name it overview.html and place it in the source tree at the directory that contains the topmost package directories. In this location, no path is needed when documenting packages, because the -sourcepath option points to this file.

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

The overview page is created only when you pass two or more package names to the javadoc tool. The title on the overview page is set by -doctitle .

-serialwarn Generates compile-time warnings for missing @serial tags. By default, javadoc generates no serial warnings. 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.

-tag name:locations:header Specifies single argument custom tags. For the javadoc tool to spell-check tag names, it is important to include a -tag option for every custom tag that is present in the source code, disabling (with X) those that aren’t being output in the current run. The colon : is always the separator. The -tag option outputs the tag heading, header, 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 header value causes the tagname to be the heading.

-taglet class Specifies the fully qualified name of 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 tool searches all subdirectories of the specified paths.

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

-use Creates class and package usage pages. Includes one Use page for each documented class and package. The page describes what packages, classes, methods, constructors and fields use any API of the specified class or package. Given class C, things that use class C would include subclasses of C, fields declared as C, methods that return C, and methods and constructors with parameters of type C. For example, you can look at the Use page for the String type. Because the getName method in the java.awt.Font class returns type String , the getName method uses String and so the getName method appears on the Use page for String . This documents only the uses of 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 docs. This text is omitted by default. To find out what version of the javadoc tool you are using, use the -J-version option.

-windowtitle title Specifies the title to be placed in the HTML 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 tool uses the value of the -doctitle option for the -windowtitle option. For example, javadoc -windowtitle "My Library" com.mypackage .

Additional Options Provided by the Standard Doclet

The following are additional options provided by the standard doclet and are subject to change without notice. Additional options might are less commonly used or are otherwise regarded as advanced.

-Xdoclint Enables recommended checks for problems in Javadoc comments.

-Xdoclint:(all|none|[-]group) Enable or disable specific checks for bad references, lack of accessibility, missing javadoc comments, and reports errors for invalid javadoc syntax and missing HTML tags.

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

When -Xdoclint is enabled, it reports issues with messages similar to the javac command. The javadoc tool 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 tool to generate invalid HTML, so these issues are reported as warnings. Syntax errors or missing HTML end tags cause the javadoc tool to generate invalid output, so these issues are reported as errors.

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

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

The following options change what the -Xdoclint option reports:

`-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 group variable has one of the following values:

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 HTML, syntax, and accessibility issues in the file filename.

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

-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 sub packages of the given package. Prefix the package specifier with a dash (-) to disable checks for the specified packages.

-Xdocrootparent url Replaces all @docRoot items followed by /.. in javadoc comments with the url.