javadoc
NAME
javadoc - Java API documentation generator SYNOPSIS
javadoc [ options ] [ packagenames ] [ sourcefilenames ] [ -subpackages [pkg1:pkg2:...] ] [ @argfiles ] ARGUMENTS
Arguments can be in any order. options Command-line options, as specified in this document. To see a typical use of javadoc options, see Real World Example. packagenames A series of names of packages, separated by spaces, such as java.lang java.lang.reflect java.awt. You must separately specify each package you want to document. javadoc uses -sourcepath to look for these package names. javadoc does not recursively traverse subpackages. Wildcards such as asterisks (*) are not allowed. See EXAMPLES, Documenting One or More Packages. sourcefiles A series of source file names, separated by spaces, each of which can begin with a path and contain a wildcard such as an asterisk (*). javadoc will process every file whose name ends with .java, and whose name, when stripped of that suffix, is actually a legal class name (see Identifiers). Therefore, you can name files with dashes (such as X-Buffer), or other illegal characters, to prevent them from being documented. This is useful for test files and files generated from templates. The path that precedes the source file name determines where javadoc will look for it. (javadoc does not use -sourcepath to look for these source file names.) For example, passing in Button.java is identical to ./Button.java. An example source file name with a full path is /home/src/java/awt/Graphics*.java. See EXAMPLES, Documenting One or More Classes. You can also mix packagenames and sourcefiles, as in EXAMPLES, Documenting Both Packages and Classes. -subpackages pkg1:pkg2:... Generates documentation from source files in the specified packages and recursively in their subpackages. An alternative to supplying packagenames or sourcefilenames. @argfiles One or more files that contain a list of javadoc options, packagenames and sourcefiles in any order. Wildcards (*) and -J options are not allowed in these files. DESCRIPTION
javadoc parses the declarations and documentation comments in a set of Java source files and produces a corresponding set of HTML pages describing (by default) the public and protected classes, nested classes (but not anonymous inner classes), interfaces, constructors, methods, and fields. You can run javadoc on entire packages, individual source files, or both. In the first case, you pass in as an argument to javadoc a series of package names. In the second case, you pass in a series of source (.java) file names. EXAMPLES are given at the end of this document. Note: When you pass in package names to javadoc, it currently processes all .java classes in the specified package directories, even if the .java files are code examples or other classes that are not actually members of the specified packages. It does not parse each .java file for a package declaration; this parsing may be added in a future release. During a run, javadoc automatically adds cross-reference links to package, class and member names that are being documented as part of that run. Links appear in several places: Declarations (return types, argument types, field types) "See Also" sections generated from @see tags In-line text generated from {@link} tags Exception names generated from @throws tags Specified by links to members in interfaces and Overrides links to members in classes Summary tables listing packages, classes and members Package and class inheritance trees The index You can add hyperlinks to existing text for classes not included on the command line (but generated separately) by way of the -link and -linkoffline options. javadoc produces one complete document each time it is run; it cannot do incremental builds -- that is, it cannot modify or directly incorporate results from previous runs of javadoc tool. However, it can link to results from previous runs, as just mentioned. As implemented, javadoc requires and relies on the java compiler to do its job. javadoc calls part of javac to compile the declarations, ignoring the member implementation. It builds a rich internal representation of the classes, including the class hierarchy and "use" relationships, then generates the HTML from that. javadoc also picks up user-supplied documentation from documentation comments in the source code. In fact, javadoc will run on .java source files that are pure stub files with no method bodies. This means you can write documentation comments and run javadoc in the earliest stages of design while creating the API, before writing the implementation. Relying on the compiler ensures that the HTML output corresponds exactly with the actual implementation, which may rely on implicit, rather than explicit, source code. For example, javadoc will document default constructors (section 8.6.7 of Java Language Specification) that are present in the .class files but not in the source code. In many cases, javadoc allows you to generate documentation for source files whose code is incomplete or erroneous. This is a benefit that enables you to generate documentation before all debugging and troubleshooting is done. For example, according to the Java Language Specification, a class that contains an abstract method should itself be declared abstract. javadoc does not check for this, and would proceed without a warning, whereas the javac compiler stops on this error. javadoc does do some primitive checking of doc comments. Use the DocCheck doclet to check the doc comments more thoroughly. When javadoc builds its internal structure for the documentation, it loads all referenced classes. Because of this, javadoc must be able to find all referenced classes, whether bootstrap classes, extensions, or user classes. For more about this, see How Classes Are Found. Generally speaking, classes you create must either be loaded as an extension or in the class path of javadoc. JAVADOC DOCLETS
You can customize the content and format of the output of javadoc by using doclets. javadoc has a default "built-in" doclet, called the standard doclet, that generates HTML-formatted API documentation. You can modify or subclass the standard doclet, or write your own doclet to generate HTML, XML, MIF, RTF or whatever output format you prefer. Information about doclets and their use is at the following locations: javadoc Doclets The -doclet command-line option When a custom doclet is not specified with the -doclet command line option, javadoc uses the default standard doclet. The javadoc tool has several command line options that are available regardless of which doclet is being used. The standard doclet adds a supplementary set of command line options. Both sets of options are described below in the options section. RELATED DOCUMENTATION AND DOCLETS
Javadoc Enhancements for details about improvements added in Javadoc 1.4. Javadoc FAQ for answers to common questions, information about Javadoc-related tools, and workarounds for bugs. How to Write Doc Comments for Javadoc for more information about Sun conventions for writing documentation comments. Requirements for Writing API Specifications - Standard requirements used when writing the Java 2 Platform Specification. It can be useful whether you are writing API specifications in source file documentation comments or in other formats. It covers requirements for packages, classes, interfaces, fields and methods to satisfy testable assertions. Documentation Comment Specification - The original specification on documentation comments, Chapter 18, Documentation Comments, in the Java Language Specification, First Edition, by James Gosling, Bill Joy, and Guy Steele. (This chapter was removed from the second edition.) DocCheck Doclet - Checks doc comments in source files and generates a report listing the errors and irregularities it finds. It is part of the Sun Doc Check Utilities. MIF Doclet - Can automate the generation of API documentation in MIF, FrameMaker and PDF formats. MIF is Adobe FrameMaker's interchange format. TERMINOLOGY
A few terms have specific meanings within the context of javadoc: generated document The document generated by the javadoc tool from the doc comments in Java source code. The default generated document is in HTML and is created by the standard doclet. name A name in the Java Language, namely the name of a package, class, interface, field, constructor, or method. A name can be partially-qualified, such as equals(Object), or fully-qualified, such as java.lang.String.equals(java.lang.Object). documented classes The classes and interfaces for which full documentation is generated during a javadoc run. To be documented, the source files must be available, and either their source filenames or package names must be passed into the javadoc command. We also refer to these as the classes included in the javadoc run, or the included classes. excluded classes Classes and interface whose source filenames or package names are not passed into the javadoc command. referenced classes The classes and interfaces that are explicitly referred to in the definition (implementation) or doc comments of the documented classes and interfaces. Examples of references include return type, parameter type, cast type, extended class, implemented interface, imported classes, classes used in method bodies, and @see, {@link}, {@linkplain}, and {@inheritDoc} tags. (Notice that this definition has changed since 1.3.) When javadoc is run, it loads into memory all of the referenced classes in the bootclasspath and classpath of javadoc. (javadoc prints a "Class not found" warning for referenced classes not found.) javadoc can derive enough information from the .class files to determine their existence and the fully qualified names of their members. external referenced classes The referenced classes whose documentation is not being generated during a javadoc run. In other words, these classes are not passed into javadoc on the command line. Links in the generated documentation to those classes are said to be external references or external links. For example, if you run javadoc on only the java.awt package, then any class in java.lang, such as Object, is an external referenced class. External referenced classes can be linked to using the -link and -linkoffline options. An important property of an external referenced class is that its source comments are normally not available to the javadoc run. In this case, these comments cannot be inherited. SOURCE FILES
javadoc generates output originating from four different types of "source" files: Java language source files for classes (.java), package comment files, overview comment files, and miscellaneous unprocessed files. CLASS SOURCE CODE FILES
Each class or interface and its members can have their own documentation comments, contained in a .java file. For more details about these doc commments, see Documentation Comments. PACKAGE COMMENT FILES
Each package can have its own documentation comment, contained in its own "source" file, that javadoc will merge into the package summary page that it generates. You typically include in this comment any documentation that applies to the entire package. To create a package comment file, you must name it package.html and place it in the package directory in the source tree along with the .java files. javadoc will automatically look for this filename in this location. Notice that the filename is identical for all packages. For explicit details, see the example of package.html. The content of the package comment file is one big documentation comment, written in HTML, like all other comments, with one exception: the documentation comment should not include the comment separators /** and */ or leading asterisks. When writing the comment, you should make the first sentence a summary about the package, and not put a title or any other text between <body> and the first sentence. You can include package tags. As with any documentation comment, all tags except {@link} must appear after the description. If you add a @see tag in a package comment file, it must have a fully qualified name. When javadoc runs, it automatically looks for this file; if found, javadoc does the following: Copies all content between <body> and </body> tags for processing. Processes any package tags that are present. Inserts the processed text at the bottom of the package summary page it generates, as shown in Package Summary. Copies the first sentence of the package comment to the top of the package summary page. It also adds the package name and this first sentence to the list of packages on the overview page, as shown in Overview Summary. The end-of-sentence is determined by the same rules used for the end of the first sentence of class and member descriptions. OVERVIEW COMMENT FILE
Each application or set of packages that you are documenting can have its own overview documentation comment, kept in its own "source" file, that javadoc merges into the overview page that it generates. You typically include in this comment any documentation that applies to the entire application or set of packages. To create an overview comment file, you can name the file anything you want, typically overview.html, and place it anywhere, typically at the top level of the source tree. Notice that you can have multiple overview comment files for the same set of source files, in case you want to run javadoc multiple times on different sets of packages. For example, if the source files for the java.applet package are contained in /home/user/src/java/applet directory, you could create an overview comment file at /home/user/src/overview.html. The content of the overview comment file is one big documentation comment, written in HTML, like the package comment file described previously. See that description for details. To reiterate, when writing the comment, you should make the first sentence a summary about the application or set of packages, and not put a title or any other text between <body> and the first sentence. You can include overview tags; as with any documentation comment, all tags except {@link} must appear after the description. If you add a @see tag, it must have a fullyqualified name. When you run javadoc, you specify the overview comment file name with the -overview option. The file is then processed, similar to that of a package comment file: Copies all content between <body> and </body> tags for processing. Processes any overview tags that are present. Inserts the processed text at the bottom of the overview page it generates, as shown in Overview Summary. Copies the first sentence of the overview comment to the top of the overview summary page. MISCELLANEOUS UNPROCESSED FILES
You can also include in your source any miscellaneous files that you want javadoc to copy to the destination directory. These typically include graphic files (for example, Java source (.java) and class (.class) files) and self-standing HTML files whose content would overwhelm the documentation comment of a normal Java source file. To include unprocessed files, put them in a directory called doc-files, which can be a subdirectory of any package directory. You can have one such subdirectory for each package. You might include images, example code, source files, .class files, applets, and HTML files. For example, if you want to include the image of a button button.gif in the java.awt.Button class documentation, you place that file in the /home/user/src/java/awt/doc-files/ directory. All links to these unprocessed files must be hard-coded, because javadoc does not look at the files -- it simply copies the directory and all its contents to the destination. For example, the link in the Button.java doc comment might look like this: /** * This button looks like this: * <img src="doc-files/Button.gif"> */ GENERATED FILES
By default, javadoc uses a standard doclet that generates HTML-formatted documentation. This doclet generates the following kinds of files (where each HTML "page" corresponds to a separate file). Notice that javadoc generates files with two types of names: those named after classes/interfaces, and those that are not (such as package-summary.html). Files in the latter group contain hyphens to prevent file name conflicts with those in the former group. BASIC CONTENT PAGES
One class or interface page (classname.html) for each class or interface it is documenting. One package page (package-summary.html) for each package it is documenting. javadoc includes any HTML text provided in a file named package.html in the package directory of the source tree. One overview page (overview-summary.html) for the entire set of packages. This is the front page of the generated document. javadoc includes any HTML text provided in a file specified with the -overview option. Notice that this file is created only if you pass into javadoc two or more package names. For further explanation, see HTML Frames. CROSS-REFERENCE PAGES One class hierarchy page for the entire set of packages (overviewtree.html). To view this, click on "Overview" in the navigation bar, then click on "Tree". One class hierarchy page for each package (package-tree.html). To view this, go to a particular package, class or interface page; click "Tree" to display the hierarchy for that package. One "use" page for each package (package-use.html) and a separate one for each class and interface (class-use/classname.html). This page describes what packages, classes, methods, constructors, and fields use any part of the given class, interface, or package. Given a class or interface A, its "use" page includes subclasses of A, fields declared as A, methods that return A, and methods and constructors with parameters of type A. You can access this page by first going to the package, class, or interface, then clicking on the "Use" link in the navigation bar. A deprecated API page (deprecated-list.html) listing all deprecated names. (A deprecated name is not recommended for use, generally due to improvements, and a replacement name is usually given. Deprecated APIs might be removed in future implementations.) A constant field values page (constant-values.html) for the values of static fields. A serialized form page (serialized-form.html) for information about serializable and externalizable classes. Each such class has a description of its serialization fields and methods. This information is of interest to re-implementors, not to developers using the API. While there is no link in the navigation bar, you can get to this information by going to any serialized class and clicking "Serialized Form" in the "See also" section of the class description. The standard doclet automatically generates a serialized form page: any class (public or non-public) that implements Serializable is included, along with readObject and writeObject methods, the fields that are serialized, and the doc comments from the @serial, @serialField, and @serialData tags. Public serializable classes can be excluded by marking them (or their package) with @serial exclude, and package-private serializable classes can be included by marking them (or their package) with @serial include. As of 1.4, you can generate the complete serialized form for public and private classes by running javadoc without specifying the -private option. An index (index-*.html) of all class, interface, constructor, field and method names, alphabetically arranged. This is internationalized for Unicode and can be generated as a single file or as a separate file for each starting character (such as A-Z for English). SUPPORT FILES
A help page (help-doc.html) that describes the navigation bar and the above pages. You can provide your own custom help file to override the default using -helpfile. One index.html file that creates the HTML frames for display. This is the file you load to display the front page with frames. This file itself contains no text content. Several frame files (*-frame.html) containing lists of packages, classes and interfaces, used when HTML frames are being displayed. A package list file (package-list), used by the -link and -linkoffline options. This is a text file, not HTML, and is not reachable through any links. A style sheet file (stylesheet.css) that controls a limited amount of color, font family, font size, font style, and positioning on the generated pages. A doc-files directory that holds any image, example, source code, or other files that you want copied to the destination directory. These files are not processed by javadoc in any manner, that is, any javadoc tags in them will be ignored. This directory is not generated unless it exists in the source tree. HTML FRAMES
javadoc generates either two or three HTML frames, as shown in the figure below. When you pass source files (*.java) or a single package name as arguments into the javadoc command, it creates only one frame (C) in the left-hand column, that is, the list of classes. When you pass into javadoc two or more package names, it creates a third frame (P) listing all packages, as well as an overview page (Detail). This overview page has the file name, overview-summary.html. Thus, this file is created only if you pass in two or more package names. You can bypass frames by clicking on the "No Frames" link or entering at overview-summary.html. If you are unfamiliar with HTML frames, you should be aware that frames can have focus for printing and scrolling. To give a frame focus, click on it. Then, on many browsers the arrow keys and page keys will scroll that frame, and the print menu command will print it. ------------ -----------|C Detail | |P| Detail | | | | | | | | | | |-| | | | | |C| | | | | | | | | | | | | | ------------ -----------javadoc *.java javadoc java.lang java.awt Load one of the following two files as the starting page depending on whether you want HTML frames or not: index.html (for frames) overview-summary.html (for no frames) GENERATED FILE STRUCTURE
The generated class and interface files are organized in the same directory hierarchy as Java source files and class files. This structure is one directory per subpackage. For example, the document generated for the class java.applet.Applet would be located at java/applet/Applet.html. The file structure for the java.applet package follows, given that the destination directory is named apidocs. All files that contain the word "frame" appear in the upper-left or lower-left frames, as noted. All other HTML files appear in the right-hand frame. NOTE: Directories are shown in bold. The asterisks (*) indicate the files and directories that are omitted when the arguments to javadoc are source file names (*.java) rather than package names. Also, when arguments are source file names, package-list is created but is empty. The doc-files directory is not created in the destination unless it exists in the source tree. apidocs Top directory index.html Initial page that sets up HTML frames * overview-summary.html Lists all packages with first sentence summaries overview-tree.html Lists class hierarchy for all packages deprecated-list.html Lists deprecated API for all packages serialized-form.html Lists serialized form for all packages * overview-frame.html Lists all packages, used in upper-left frame allclasses-frame.html Lists all classes for all packages, used in lower-left frame help-doc.html Lists user help for how these pages are organized index-all.html Default index created without -splitindex index-files Directory created with -splitindex index-<number>.html Index files created with -splitindex package-list Lists package names, used only for resolving external refs stylesheet.css HTML style sheet for defining fonts, colors and positions java Package directory applet Subpackage directory Applet.html Page for Applet class AppletContext.html Page for AppletContext interface AppletStub.html Page for AppletStub interface AudioClip.html Page for AudioClip interface * package-summary.html Lists classes with first sentence summaries for this package * package-frame.html Lists classes in this package, used in lower left-hand frame * package-tree.html Lists class hierarchy for this package package-use Lists where this package is used doc-files Directory holding image and example files class-use Directory holding pages API is used Applet.html Page for uses of Applet class AppletContext.html Page for uses of AppletContext interface AppletStub.html Page for uses of AppletStub interface AudioClip.html Page for uses of AudioClip src-html Source code directory java Package directory applet Subpackage directory Applet.html Page for Applet source code AppletContext.html Page for AppletContext source code AppletStub.html Page for AppletStub source code AudioClip.html Page for AudioClip source code GENERATED API DECLARATIONS
The Javadoc tool generates a declaration at the start of each class, interface, field, constructor, and method description. This declaration is the declaration for that API item. For example, the declaration for the Boolean class is: public final class Boolean extends Object implements Serializable and the declaration for the Boolean.valueOfmethod is: public static Boolean valueOf(String s) The Javadoc tool can include the modifiers public, protected, private, abstract, final, static, transient, and volatile, but not synchronized or native. These last two modifiers are considered implementation detail and not part of the API specification. Rather than relying on the keyword synchronized, APIs should document their concurrency semantics in the comment description, as in "a single Enumeration cannot be used by multiple threads concurrently". The document should not describe how to achieve these semantics. As another example, while Hashtable should be thread-safe, there's no reason to specify that we achieve this by synchronizing all of its exported methods. We should reserve the right to synchronize internally at the bucket level, thus offering higher concurrency. DOCUMENTATION COMMENTS
The original "Documentation Comment Specification" can be found under related documentation. Commenting the Source Code You can include documentation comments ("doc comments") in the source code, ahead of declarations for any class, interface, method, constructor, or field. You can also create doc comments for each package and another one for the overview, though their syntax is slightly different. Doc comments are also known as Javadoc comments. A doc comment consists of the characters between the characters /** that begin the comment and the characters */ that end it. Leading asterisks are allowed on each line and are described further below. The text in a comment can continue onto multiple lines. /** * This is the typical format of a simple documentation comment. */ To save space you can put a comment on one line: /** This comment takes up only one line. */ Documentation comments are recognized only when placed immediately before class, interface, constructor, method, or field declarations (see the class example, method example, and field example). Documentation comments placed in the body of a method are ignored. Only one documentation comment per declaration statement is recognized by javadoc. A common mistake is to put an import statement between the class comment and the class declaration. Avoid this, as javadoc will ignore the class comment. /** * This is the class comment for the class Whatever. */ import com.sun; // MISTAKE - Important not to put statements here public class Whatever { } A comment is a description followed by a tag section. The description begins after the starting delimiter /** and continues until the tag section. The tag section starts with the first character @ that begins a line (ignoring leading asterisks, white space, and separator /**). It is possible to have a comment with only tags and no description. The description cannot continue after the tag section begins. The argument to a tag can span multiple lines. There can be any number of tags -- some types of tags can be repeated while others cannot. This @see starts the tag section: /** * This is a doc comment. * @see java.lang.Object */ Standalone and In-line Tags A tag is a special keyword within a doc comment that javadoc can process. javadoc has standalone tags, which appear as @tag, and in-line tags, which appear within braces, as {@tag}. To be interpreted, a standalone tag must appear at the beginning of a line, ignoring leading asterisks, white space, and separator (/**). This means you can use the @ character elsewhere in the text and it will not be interpreted as the start of a tag. If you want to start a line with the @ character and not have it be interpreted, use the HTML entity @. Each standalone tag has associated text, which includes any text following the tag up to, but not including, either the next tag, or the end of the doc comment. This associated text can span multiple lines. An in-line tag is allowed and interpreted anywhere that text is allowed. The following example contains the standalone tag @deprecated and in-line tag {@link}. /** * @deprecated As of JDK 1.1, replaced \ by {@link #setBounds(int,int,int,int)} */ Comments are written in HTML The text must be written in HTML so that comments can use HTML entities and HTML tags. You can use whichever version of HTML your browser supports; we have written the standard doclet to generate HTML 3.2-compliant code elsewhere (outside of the documentation comments) with the inclusion of cascading style sheets and frames. (We preface each generated file with "HTML 4.0" because of the frame sets.) For example, entities for the less-than (<) and greater-than (>) symbols should be written < and >. Likewise, the ampersand (&) should be written &. The bold HTML tag <b> is shown in the following example: /** * This is a <b>doc</b> comment. * @see java.lang.Object */ Leading Asterisks When javadoc parses a doc comment, leading asterisk (*) characters on each line are discarded. Blanks and tabs preceding the initial asterisk (*) characters are also discarded. Starting with 1.4, if you omit the leading asterisk on a line, the leading white space is no longer removed. This enables you to paste code examples directly into a doc comment inside a <pre> tag, and its indentation will be honored. Spaces are generally interpreted by browsers more uniformly than tabs. Indentation is relative to the left margin (rather than the separator /** or tag). First Sentence The first sentence of each doc comment should be a summary sentence, containing a concise but complete description of the declared entity. This sentence ends at the first period that is followed by a blank, tab, or line terminator, or at the first standalone tag. javadoc copies this first sentence to the member summary at the top of the HTML page. See -breakiterator for a description of how we are planning in a future release to change the way the sentence break is determined. Declaration With Multiple Fields Java allows declaring multiple fields in a single statement, but this statement can have only one documentation comment, which is copied for all fields. Therefore, if you want individual documentation comments for each field, you must declare each field in a separate statement. For example, the following documentation comment does not make sense when written as a single declaration and would be better handled as two declarations: /** * The horizontal and vertical distances of point (x,y) */ public int x, y; // Avoid this javadoc generates the following documentation from the above code: public int x The horizontal and vertical distances of point (x,y). public int y The horizontal and vertical distances of point (x,y). Use Header Tags Carefully When writing documentation comments for members, it is best not to use HTML heading tags such as <H1> and <H2>, because javadoc creates an entire structured document and these structural tags can interfere with the formatting of the generated document. However, it is fine to use these headings in class and package comments to provide your own structure. Automatic Re-use of Method Comments The Javadoc tool has the ability to automatically reuse or "inherit" method comments in classes an interfaces. When a description, or @return, @param, @see or @throws tag is missing from a method comment, javadoc instead copies the corresponding description or tag comment from the method it overrides or implements (if any), according to the algorithm below. More specifically, when a @param tag for a particular parameter is missing, then the comment for that parameter is copied. When a @throws tag for a particular exception is missing, the @throws tag is copied only if that exception is declared. This behavior contrasts with version 1.3 and earlier, where the presence of any description or tag would prevent all comments from being inherited. Also of interest, if the inline tag {@inheritDoc} is present in a description or any tag, the corresponding description or tag is copied at that spot. The overridden method must be a member of a documented class, and not an external referenced class for the doc comment to actually be available to copy. Inheriting of comments occurs in three cases: When a method in a class overrides a method in a superclass. When a method in an interface overrides a method in a superinterface. When a method in a class implements a method in an interface. In the first two cases, for method overrides, the Javadoc tool generates a subheading "Overrides" in the documentation for the overriding method, with a link to the method it is overriding. In the third case,when a method in a given class implements a method in an interface, the Javadoc tool generates a subheading "Specified by" in the documentation for the overriding method, with a link to the method it is implementing. Algorithm for Inheriting Method Descriptions If a method does not have a doc comment, javadoc searches for an applicable comment using the following algorithm, which is designed to find the most specific applicable doc comment, giving preference to interfaces over superclasses: 1. Look in each directly implemented (or extended) interface in the order they appear following the word implements (or extends) in the method declaration. Use the first doc comment found for this method. 2. If step 1 failed to find a doc comment, recursively apply this entire algorithm to each directly implemented (or extended) interface, in the same order they were examined in step 1. 3. If step 2 failed to find a doc comment and this is a class other than Object (not an interface): 3a. If the superclass has a doc comment for this method, use it. 3b. If step 3a failed to find a doc comment, recursively apply this entire algorithm to the superclass. JAVADOC TAGS
javadoc parses special tags when they are embedded within a Javadoc comment. These doc tags enable you to autogenerate a complete, wellformatted API from your source code. The tags start with an "at" sign (@) and are case-sensitive; that is, they must be typed with the uppercase and lowercase letters as shown. A tag must start at the beginning of a line (after any leading spaces and an optional asterisk) or it is treated as normal text. By convention, tags with the same name are grouped together. For example, put all @see tags together. Tags come in two types: Standalone tags - Can be placed only in the tag section that follows the description. These tags are not set off with curly braces: @tag. Inline tags - Can be placed anywhere in the comment description or in the comments for standalone tags. Inline tags are set off with curly braces: {@tag}. For information about tags might be introduced in future releases, see Proposed Tags. The current tags are: +--------------+-------------+ | Tag | Introduced | | in JDK +--------------+-------------+ |@author | 1.0 |{@docRoot} | 1.3 |@deprecated | 1.0 |@exception | 1.0 |{@inheritDoc} | 1.4 |{@link} | 1.2 |{@linkplain} | 1.4 |@param | 1.0 |@return | 1.0 |@see | 1.0 |@serial | 1.2 |@serialData | 1.2 |@serialField | 1.2 |@since | 1.1 |@throws | 1.2 |{@value} | 1.4 |@version | 1.0 +--------------+-------------+ For custom tags, see the -tag option. @author name-text Adds an "Author" entry with the specified name-text to the generated docs when the -author option is used. A doc comment can contain multiple @author tags. You can specify one name per @author tag or multiple names per tag. In the former case, javadoc inserts a comma (,) and space between names. In the latter case, the entire text is copied to the generated document without being parsed. Therefore, use multiple names per line if you want a localized name separator other than a comma. @deprecated deprecated-text Adds a comment indicating that this API should no longer be used (even though it might continue to work). javadoc moves the deprecated-text ahead of the description, placing it in italics and preceding it with a bold warning: "Deprecated". The first sentence of deprecated-text should at least tell the user when the API was deprecated and what to use as a replacement. javadoc copies just the first sentence to the summary section and index. Subsequent sentences can also explain why it has been deprecated. You should include a {@link} tag (for javadoc 1.2 or later) that points to the replacement API: For javadoc 1.2 and later, use a {@link} tag. This creates the link in-line, where you want it. For example: /** * @deprecated As of JDK 1.1, replaced by * {@link #setBounds(int,int,int,int)} */ For javadoc 1.1, the standard format is to create a @see tag (which cannot be in-line) for each @deprecated tag. For more about deprecation, see the @deprecated tag. {@docRoot} Represents the relative path to the generated document's (destination) root directory from any generated page. It is useful when you want to include a file, such as a copyright page or company logo, that you want to reference from all generated pages. Linking to the copyright page from the bottom of each page is common. This {@docRoot} tag can be used both on the command line and in a doc comment: 1. On the command line, where the header/footer/bottom are defined: javadoc -bottom '<a href="{@docRoot}/copyright.html">Copyright</a>' 2. In a doc comment: /** * See the <a href="copyright.html">Copyright</a>. */ The reason this tag is needed is because the generated docs are in hierarchical directories, as deep as the number of subpackages. This expression: <a href="copyright.html"> would resolve to: <a href="copyright.html"> ... for java/lang/Object.java and <a href="copyright.html"> ... for java/lang/ref/Reference.java @exception class-name description The @exception tag is a synonym for @throws. {@inheritDoc} Inherits documentation from the nearest superclass into the current doc comment. This allows comments to be abstracted up the inheritance tree, and enables developers to write around the copied text. Also see inheriting comments. This tag can be placed in two positions: In the comment body (before the first standalone tag), where it will copy the entire comment body from its superclass. In the text argument of a standalone tag, where it will copy the text of the tag from its superclass. {@link package.class#member label} Inserts an in-line link with visible text label that points to the documentation for the specified package, class or member name of a referenced class. This tag is very simliar to @see -- both require the same references and accept exactly the same syntax for package.class#member and label. The main difference is that {@link} generates an in-line link rather than placing the link in the "See Also" section. Also, the {@link} tag begins and ends with curly braces to separate it from the rest of the in-line text. If you need to use "}" inside the label, use the HTML entity notation }. There is no limit to the number of {@link} tags allowed in a sentence. You can use this tag in the description part of a documentation comment or in the text portion of any tag (such as @deprecated, @return, or @param). For example, here is a comment that refers to the getComponentAt(int, int) method: Use the {@link #getComponentAt(int, int) getComponentAt} method. From this, the standard doclet would generate the following HTML (assuming it refers to another class in the same package): Use the <a href="Component.html">\ getComponentAt</a>method. which appears on the web page as: Use the getComponentAt method. {@linkplain package.class#member label} Identical to {@link}, except the link's label is displayed in plain text than code font. Useful when the label is plain text. Example: Refer to {@linkplain add() the overridden method}. This would display as: Refer to the overridden method. @param parameter-name description Adds a parameter to the "Parameters" section. The description can continue on the next line. @return description Adds a "Returns" section with the description text. This text should describe the return type and permissible range of values. @see reference Adds a "See Also" heading with a link or text entry that points to reference. A doc comment can contain any number of @see tags, which are all grouped under the same heading. The @see tag has three variations; the third form below is the most common. @see string Note: This form is broken in JDK 1.2 (prints none of the quoted text) but is fixed in JDK 1.2.2. Adds a text entry for string. No link is generated. The string is a book or other reference to information not available by URL. javadoc distinguishes this from the previous cases by looking for a double-quote (") as the first character. For example: @see "The Java Programming Language" This generates text such as: See Also: "The Java Programming Language" @see <a href="URL#value">label</a> Adds a link as defined by URL#value. The URL#value is a relative or absolute URL. javadoc distinguishes this from other cases by looking for a less-than symbol (<) as the first charac- ter. For example: @see <a href="spec.html">Java Spec</a> This generates a link such as: See Also: Java Spec @see package.class#member label Adds a link, with visible text label, that points to the documentation for the specified name in the Java Language. The label is optional; if omitted, the name appears instead as the visible text, suitably shortened (see How a Name Is Displayed). Use the label when you want the visible text to be abbreviated or different from the name. In only version 1.2, just the name but not the label would automatically appear in <code> HTML tags. Starting with JDK 1.2.2, the <code> is always included around the visible text, whether or not a label is used. package.class#member is any valid name in the Java Language that is referenced (package, class, interface, constructor, method, or field name), except that you replace the dot ahead of the member name with a hash character (#). If this name is in the documented classes, javadoc automatically creates a link to it. To create links to external referenced classes, use the -link option. Use either of the other two @see forms for referring to documentation of a name that does not belong to a referenced class. This argument is described at greater length below under Specifying a Name. label is optional text that is visible as the link's label. The label can contain white space. If a label is omitted, then package.class.member will appear, suitably shortened relative to the current class and package (see How a Name Is Displayed). A space is the delimiter between package.class#member and label. A space inside parentheses does not indicate the start of a label, so spaces can be used between parameters in a method. In the example below, an @see tag (in the Character class) refers to the equals method in the String class. The tag includes both arguments, that is, the name "String#equals(Object)" and the label "equals": /** * @see String#equals(Object) equals */ The standard doclet produces HTML something like this: <dl> <dt><b>See Also:</b> <dd><a href="../../java/lang/String#equals\ (java.lang.Object)"><code>equals</code></a> </dl> The above looks something like this in a browser, where the label is the visible link text: See Also: equals Specifying a Name: This package.class#member name can be either fully qualified, such as java.lang.String#toUpperCase(), or not, such as String#toUpperCase() or #toUpperCase(). If less than fully-qualified, javadoc uses the normal Java compiler search order to find it, further described below in Search order for @see. The name can contain whitespace within parentheses, such as between method arguments. The advantage to providing shorter, "partially-qualified" names is that they require less typing and make less clutter in the source code. The following table shows the different forms of the name, where Class can be a class or interface, Type can be a class, interface, array, or primitive, and method can be a method or constructor. +-----------------------------------------------------------+ | Typical forms for @see package.class#member +-----------------------------------------------------------+ |Referencing a member of the current class |@see #field |@see #method(Type, Type,...) |@see #method(Type argname, Type argname,...) |Referencing another class in the current or imported |packages |@see Class#field |@see Class#method(Type, Type,...) |@see Class#method(Type argname, Type argname,...) |@see Class |Referencing another package (fully qualified) |@see package.Class#field |@see package.Class#method(Type, Type,...) |@see package.Class#method(Type argname, Type argname,...) |@see package.Class |@see package +-----------------------------------------------------------+ The following notes apply to the above table: The first set of forms (with no class or package) will cause javadoc to search only through the current class's hierarchy. It finds a member of the current class or interface, one of its superclasses or superinterfaces, or one of its enclosing classes or interfaces (search steps 1-3). It will not search the rest of the current package or other packages (search steps 4-5). If any method or constructor is entered as a name with no parentheses, such as getValue, and if no field with the same name exists, javadoc will correctly create a link to it, but will print a warning message reminding you to add the parentheses and arguments. If this method is overloaded, javadoc links to the first method that its search encounters, which is unspecified. Nested classes must be specified as outer.inner, not only inner, for all forms. As stated, the hash character (#), rather than a dot (.), separates a member from its class. This enables javadoc to resolve ambiguities, since the dot also separates classes, inner classes, packages, and subpackages. The hash character is absolutely necessary in the forms above where it is the first character. However, in other forms, javadoc is generally lenient and allows a dot if it does not produce an ambiguity, though it does print a warning. Search Order for @see: javadoc will process an @see tag that appears in a source file (.java), package file (package.html), or overview file (overview.html). In the latter two files, you must fully qualify the name you supply with @see. In a source file, you can specify a name that is fully qualified or partially qualified. When javadoc encounters an @see tag in a .java file that is not fully qualified, it searches for the specified name in the same order as the Java compiler would (except javadoc will not detect certain namespace ambiguities, since it assumes the source code is free of these errors). This search order is formally defined in Chapter 6, "Names" of the Java Language Specification, modified by the Inner Classes Specification. javadoc searches for that name through all related and imported classes and packages. In particular, it searches in this order: 1. The current class or interface 2. Any enclosing classes and interfaces, searching closest first 3. Any superclasses and superinterfaces, searching closest first 4. The current package 5. Any imported packages, classes and interfaces, searching in the order of the import statement javadoc continues to search recursively through steps 1-3 for each class it encounters until it finds a match. That is, after it searches through the current class and its enclosing class E, it searches through E's superclasses before E's enclosing classes. In steps 4 and 5, javadoc does not search classes or interfaces within a package in any specified order (that order depends on the particular compiler). In step 5, javadoc will look in java.lang, since that is automatically imported by all programs. javadoc will not necessarily look in subclasses, nor will it look in other packages even if their documentation is being generated in the same run. For example, if the @see tag is in java.awt.event.KeyEvent class and refers to a name in the java.awt package, javadoc will not look in that package unless that class imports it. How a Name is Displayed: If label is omitted, then package.class.member will appear. In general, it will be suitably shortened relative to the current class and package. By "shortened", we mean javadoc will display only the minimum name necessary. For example, if the String.toUpperCase() method contains references to a member of the same class and to a member of a different class, the class name will be displayed only in the latter case: Type Example Displays As of Reference @see tag @see toLowerCase() refers String#toLowerCase() (omits the class name) to member of the same class @see @see Character.toLowerCase(char) tag Character#toLowerCase(char) (includes the class name) refers to member of a different class Examples of @see: The comment to the right shows how the name would be displayed if the @see tag is in a class in another package, such as java.applet.Applet: Example See also: @see java.lang.String // String @see java.lang.String The String class // The String class @see String // String @see String#equals(Object) // String.equals(Object) @see String#equals // String.equals\ (java.lang.Object) @see java.lang.Object#wait(long) // java.lang.Object.\ wait(long) @see Character#MAX_RADIX // Character.MAX_RADIX @see <a href="spec.html">Java Spec</a> // Java Spec @see "The Java Programming Language" // "The Java Programming \ Language" You can extend @see to link to classes not being documented by using the -link option. Notice that this works only for classes that are referenced in a particular way as described at How an Excluded Class Must Be Referenced for a Link to Appear. @since since-text Adds a "Since" heading with the specified since-text to the generated documentation. The text has no special internal structure. This tag means that this change or feature has existed since the software release specified by the since-text. For example: @since 1.4 For source code in the Java platform, this tag indicates the version of the Java platform API specification (not necessarily when it was added to the reference implementation). @serial field-description | include | exclude Used in the doc comment for a default serializable field. An optional field-description should explain the meaning of the field and list the acceptable values. If needed, the description can span multiple lines. The standard doclet adds this information to the serialized form page. If a serializable field was added to a class some time after the class was made serializable, a statement should be added to its description to identify at which version it was added. The include and exclude arguments identify whether a class or package should be included or excluded from the serialized form page. They work as follows: A public or protected class that implements Serializable is included unless that class (or its package) is marked @serial exclude. A private or package-private class that implements Serializable is excluded unless that class (or its package) is marked @serial include. Examples: The javax.swing package is marked @serial exclude (in package.html). The public class java.security.BasicPermission is marked @serial exclude. The package-private class java.util.PropertyPermissionCollection is marked @serial include. The tag @serial at a class level overrides @serial at a package level. The @since tag should be added to each serializable field that has been added since the initial version of a Serializable class to identify when it was added. For more information about how to use these tags, along with an example, see "Documenting Serializable Fields and Data for a Class," Section 1.6 of the Java Object Serialization Specification. Also see the "Serialization FAQ," which covers questions such as "Why do I see javadoc warnings stating that I am missing @serial tags for private fields if I am not running javadoc with the -private switch?" @serialField field-name field-type field-description Documents an ObjectStreamField component of a Serializable class's serialPersistentFields member. One @serialField tag should be used for each ObjectStreamField component. @serialData data-description A data-description documents the sequences and types of data, specifically the optional data written by the writeObject method and all data written by the Externalizable.writeExternal method. The @serialData tag can be used in the doc comment for the writeObject, readObject, writeExternal, and readExternal methods. @throws class-name description The @throws and @exception tags are synonyms. Adds a "Throws" subheading to the generated documentation, with the class-name and description text. The class-name is the name of the exception that can be thrown by the method. If this class is not fully specified, the Javadoc tool uses the search order to look up this class. A @throws tag's comment documented in a superclass or interface is inherited in two cases: (1) for a corresponding exception declared in a throws clause of the subclass and (2) for all runtime exceptions. If neither is the case and you want to force the documentation to be inherited, then use {@inheritDoc}. {@value} When used in a static field comment, displays the value of the constant. These are the values displayed on the Constant Field Values page. @version version-text Adds a "Version" subheading with the specified version-text to the generated docs when the -version option is used. The text has no special internal structure. A doc comment can contain at most one @version tag. Version normally refers to the version of the software (such as the JDK) that contains this class or member. WHERE TAGS CAN BE USED
The following sections describe where the tags can be used. Notice that these four tags can be used in all doc comments: @see, @link, @since, @deprecated. OVERVIEW DOCUMENTATION TAGS
Overview tags are tags that can appear in the documentation comment for the overview page, which resides in the source file typically named (overview.html). As in any other documentation comments, these tags must appear after the description. NOTE: The {@link} tag has a bug in overview documents in version 1.2 \m( text appears properly but has no link. The {@docRoot} tag does not currently work in overview documents. +--------------+ |Overview Tags +--------------+ |@see |@since |@author |@version |{@link} |{@linkplain} |{@docRoot} +--------------+ PACKAGE DOCUMENTATION TAGS
Package tags are tags that can appear in the documentation comment for a package (which resides in the source file named package.html). The @serial tag can only be used here with the include or exclude argument. +-------------+ |Package Tags +-------------+ |@see |@since |@deprecated |@serial |@author |@version |{@link} |{@linkplain} |{@docRoot} +-------------+ CLASS AND INTERFACE DOCUMENTATION TAGS
The following are tags that can appear in the documentation comment for a class or interface. The @serial tag can only be used here with the include or exclude argument. +---------------------+ |Class/Interface Tags +---------------------+ |@see |@since |@deprecated |@serial |@author |@version |{@link} |{@linkplain} |{@docRoot} +---------------------+ An example of a class comment: /** * A class representing a window on the screen. * For example: * <pre> * Window win = new Window(parent); * win.show(); * </pre> * * @author Sami Shaio * @version 1.15, 08/03/00 * @see java.awt.BaseWindow * @see java.awt.Button */ class Window extends BaseWindow { } FIELD DOCUMENTATION TAGS
The following are the tags that can appear in the documentation comment for a field. +-------------+ | Field Tags +-------------+ |@see |@since |@deprecated |@serial |@serialField |{@link} |{@linkplain} |{@docRoot} |{@value} +-------------+ An example of a field comment: /** * The X-coordinate of the component. * * @see #getLocation() */ int x = 1263732; CONSTRUCTOR AND METHOD DOCUMENTATION TAGS
The following are the tags that can appear in the documentation comment for a constructor or method, except for {@inheritDoc}, which cannot appear in a constructor. +------------------------+ |Method/Constructor Tags +------------------------+ |@see |@since |@deprecated |@param |@return |@throws (@exception) |@serialData |{@link} |{@linkplain} |{@inheritDoc} |{@docRoot} +------------------------+ An example of a method doc comment: /** * Returns the character at the specified index. An index * ranges from <code>0</code> to <code>length() - 1</code>. * * @param index the index of the desired character. * @return the desired character. * @exception StringIndexOutOfRangeException * if the index is not in the range <code>0</code> * to <code>length()-1</code>. * @see java.lang.Character#charValue() */ public char charAt(int index) { } OPTIONS
The javadoc tool uses doclets to determine its output. javadoc uses the default standard doclet unless a custom doclet is specified with the -doclet option. javadoc provides a set of command-line options that can be used with any doclet. These options are described below under the sub-heading javadoc Options. The standard doclet provides an additional set of command-line options that are described below, under the sub-heading Options Provided by the Standard Doclet. All option names are case-insensitive, though their arguments can be case-sensitive. The options are: -1.1 -header -private -author -help -protected -bootclasspath -helpfile -public -bottom -J -quiet -breakiterator -link -serialwarn -charset -linkoffline -source -classpath -linksource -sourcepath -d -locale -splitindex -docencoding -nocomment -stylesheetfile -docfilessubdirs -nodeprecated -subpackages -doclet -nodeprecatedlist -tag -docletpath -nohelp -taglet -doctitle -noindex -tagletpath -encoding -nonavbar -title -exclude -noqualifier -use -excludedocfilessubdir -nosince -verbose -ffooootteers -oovveervviiew -wwiinnddoowwttitle -group -package JAVADOC OPTIONS
-overview path/filename Specifies that javadoc should retrieve the text for the overview documentation from the "source" file specified by path/filename and place it on the Overview page (overview-summary.html). The path/filename is relative to the -sourcepath. While you can use any name you want for filename and place it anywhere you want for path, a typical thing to do is to name it overview.html and place it in the source tree at the directory that contains the topmost package directories. In this location, no path is needed when documenting packages, since -sourcepath will point to this file. For example, if the source tree for the java.lang package is /src/classes/java/lang/, then you could place the overview file at /src/classes/overview.html. See Real World Example. For information about the file specified by path/filename, see overview comment file. Notice that the overview page is created only if you pass into javadoc two or more package names. For further explanation, see HTML Frames. The title on the overview page is set by -doctitle. -public Shows only public classes and members. -protected Shows only protected and public classes and members. This is the default. -package Shows only package, protected, and public classes and members. -private Shows all classes and members. -help Displays the online help, which lists these javadoc and doclet command line options. -doclet class Specifies the class file that starts the doclet used in generating the documentation. Use the fully-qualified name. This doclet defines the content and formats the output. If the -doclet option is not used, javadoc uses the standard doclet for generating the default HTML format. This class must contain the start(Root) method. The path to this starting class is defined by the -docletpath option. For example, to call the MIF doclet, use: -doclet com.sun.tools.doclets.mif.MIFDoclet -docletpath classpathlist Specifies the path to the doclet starting class file (specified with the -doclet option) and any JAR files it depends on. If the starting class file is in a jar file, the this specifies the path to that jar file, as shown in the example below. You can specify an absolute path or a path relative to the current directory. If classpathlist contains multiple paths or JAR files, they should be separated with a colon (:). This option is not necessary if the doclet is already in the search path. Example of path to jar file that contains the starting doclet class file. Notice the jar filename is included. -docletpath /home/user/mifdoclet/lib/mifdoclet.jar Example of path to starting doclet class file. Notice the class filename is omitted. -docletpath /home/user/mifdoclet/classes/com/sun/tools/doclets/mif/ -1.1 This feature has been removed from javadoc 1.4. There is no replacement for it. This option created documentation with the appearance and functionality of documentation generated by javadoc 1.1 (including never supporting nested classes). If you need this option, use javadoc 1.2 or 1.3 instead. -sourcepath sourcepathlist Specifies the search paths for finding source files (.java) when passing package names into the javadoc command. The sourcepathlist can contain multiple paths by separating them with a colon (:). javadoc will search in all subdirectories of the specified paths. Note that this option is not only used to locate the source files being documented, but also to find source files that are not being documented but whose comments are inherited by the source files being documented. Notice that you can use the -sourcepath option only when passing package names into the javadoc command; it will not locate .java files passed into the javadoc command. (To locate .java files, cd to that directory or include the path ahead of each file, as shown at Documenting One or More Classes.) If -sourcepath is omitted, javadoc uses the class path to find the source files (see -classpath). Therefore, the default -sourcepath is the value of class path. If -classpath is omitted and you are passing package names into javadoc, it looks in the current directory (and subdirectories) for the source files. Set sourcepathlist to the root directory of the source tree for the package you are documenting. For example, suppose you want to document a package called com.mypackage whose source files are located at: /home/user/src/com/mypackage/*.java In this case, you would specify the source path to /home/user/src, the directory that contains com/mypackage, and then supply the package name com.mypackage: example% javadoc -sourcepath /home/user/src/ com.mypackage This is easy to remember by noticing that if you concatenate the value of the source path and the package name together and change the dot to a slash "/", you end up with the full path to the package: /home/user/src/com/mypackage To point to two source paths: example% javadoc -sourcepath /home/u1/src:/home/u2/src \ com.mypackage -classpath classpathlist Specifies the paths where javadoc looks for referenced classes (.class); these are the documented classes plus any classes referenced by those classes. javadoc searches in all subdirectories of the specified paths. The class path list can contain multiple paths by separating them with a colon. javadoc will search in all subdirectories of the specified paths. Follow the instructions in class path documentation for specifying classpathlist. If -sourcepath is omitted, javadoc uses -classpath to find the source files as well as class files (for backward compatibility). Therefore, if you want to search for source and class files in separate paths, use both -sourcepath and -classpath. For example, if you want to document com.mypackage, whose source files reside in the directory /home/user/src/com/mypackage, and if this package relies on a library in /home/user/lib, you would specify: example% javadoc -classpath /home/user/lib -sourcepath \ /home/user/src com.mypackage As with other tools, if you do not specify -classpath, javadoc uses the CLASSPATH environment variable, if it is set. If both are not set, javadoc searches for classes from the current directory. For an in-depth description of how javadoc uses -classpath to find user classes as it relates to extension classes and bootstrap classes, see How Classes Are Found. -bootclasspath classpathlist Specifies the paths where the boot classes reside. These are nominally the Java platform classes. The bootclasspath is part of the search path javadoc will use to look up source and class files. See How Classes Are Found for more details. Separate directories in dirlist with colons (:). -extdirs dirlist Specifies the directories where extension classes reside. These are any classes that use the Java Extension mechanism. The extdirs is part of the search path javadoc uses to look up source and class files. See -classpath (above) for more details. Separate directories in dirlist with colons (:). -verbose Provides more detailed messages while javadoc is running. Without the -verbose option, messages appear for loading the source files, generating the documentation (one message per source file), and sorting. The -verbose option causes the printing of additional messages specifying the number of milliseconds to parse each Java source file. -quiet Shuts off non-error and non-warning messages, leaving only the warnings and errors visible, making them easier to view. Also suppresses the version string. -locale language_country_variant Important: The -locale option must be placed ahead (to the left) of any options provided by the standard doclet or any other doclet. Otherwise, the navigation bars will appear in English. This is the only command-line option that is order-dependent. Specifies the locale that javadoc uses when generating documentation. The argument is the name of the locale, as described in java.util.Locale documentation, such as en_US (English, United States) or en_US_WIN (Windows variant). Specifying a locale causes javadoc to choose the resource files of that locale for messages (strings in the navigation bar, headings for lists and tables, help file contents, comments in stylesheet.css, and so forth). It also specifies the sorting order for lists sorted alphabetically, and the sentence separator to determine the end of the first sentence. It does not determine the locale of the doc comment text specified in the source files of the documented classes. -encoding name Specifies the source file encoding name, such as EUCJIS/SJIS. If this option is not specified, the platform default converter is used. -Jflag Passes flag directly to the Java runtime system that runs javadoc. Notice there must be no space between the -J and the flag. For example, if you need to ensure that the system sets aside 32 megabytes of memory in which to process the generated documentation, then you would use this flag as follows: example% javadoc -J-Xmx32m -J-Xms32m com.mypackage -noindex Omits the index from the generated docs. The index is produced by default. -nohelp Omits the HELP link in the navigation bars at the top and bottom of each page of output. -nonavbar Prevents the generation of the navigation bar, header and footer, otherwise found at the top and bottom of the generated pages. Has no effect on the "bottom" option. The -nonavbar option is useful when you are interested only in the content and have no need for navigation, such as converting the files to PostScript or PDF for print only. -helpfile path/filename Specifies the path of an alternate help file path/filename that the HELP link in the top and bottom navigation bars link to. Without this option, javadoc automatically creates a help file help-doc.html that is hard-coded in javadoc. This option enables you to override this default. The file name can be any name and is not restricted to help-doc.html; javadoc will adjust the links in the navigation bar accordingly. For example: example% javadoc -helpfile /home/doc/myhelp.html java.awt -stylesheetfile path/filename Specifies the path of an alternate HTML stylesheet file. Without this option, javadoc automatically creates a stylesheet file, stylesheet.css, that is hard-coded in javadoc. This option enables you to override this default. The file name can be any name and is not restricted to stylesheet.css. For example: example% javadoc -stylesheetfile \ /home/doc/mystylesheet.css java.awt -serialwarn Generates compile-time warnings for missing @serial tags. By default, javadoc 1.2.2 (and later versions) generates no serial warnings. (This is a reversal from earlier versions.) Use this option to display the serial warnings, which helps to properly document default serializable fields and writeExternal methods. -charset name Specifies the HTML character set for this document. For example: % javadoc -charset "iso-8859-1" mypackage would insert the following line in the head of every generated page: <META http-equiv="Content-Type" content="text/html; charset=iso-885 9-1"> This META tag is described in the HTML standard (4197265 and 4137321). -docencoding name Specifies the encoding of the generated HTML files. EXAMPLES
You can run javadoc on entire packages or individual classes. Each package name has a corresponding directory name. In the following examples, the source files are located at /home/src/java/awt/*java. The destination directory is /home/html. Documenting One or More Packages To document a package, the source files (*.java) for that package must be located in a directory having the same name as the package. If a package name is made up of several identifiers (separated by dots), each identifier represents a different directory. Thus, all java.awt classes must reside in a directory named java/awt/. You can run javadoc either of the following two ways: by changing directories (with cd) or by using -sourcepath option. You cannot use wildcards to specify groups of packages. Case 1 Changing to the package directory: Change to the parent directory of the fully qualified package. Then run javadoc, supplying names of one or more packages you want to document: example% cd /home/src/ example% javadoc -d /home/html java.awt java.awt.event Case 2 From any directory: In this case, it does not matter what the current directory is. Run javadoc supplying -sourcepath with the parent directory of the fully qualified package, and supply names of one or more packages you want to document: example% javadoc -d /home/html -sourcepath /home/src \ java.awt java.awt.event Both cases generate HTML-formatted documentation for the public and protected classes and interfaces in packages java.awt and java.awt.event and save the HTML files in the specified destination directory (/home/html). Because two or more packages are being generated, the document has three frames: for the list of packages, the list of classes, and the main page. Documenting One or More Classes The second way to run javadoc is by passing in one or more source files (.java). You can run javadoc either of the following two ways: by changing directories (with cd) or by fully specifying the path to the .java files. Relative paths are relative to the current directory. The -sourcepath option is ignored when passing in source files. You can use command line wildcards, such as asterisk (*), to specify groups of classes. Case 1 Changing to the source directory: Change to the directory holding the .java files. Then run javadoc, supplying names of one or more source files you want to document. example% cd /home/src/java/awt example% javadoc -d /home/html Button.java Canvas.java \ Graphics*.java This example generates HTML-formatted documentation for the classes Button, Canvas, and classes beginning with Graphics. Because source files rather than package names were passed in as arguments to javadoc, the document has two frames, for the list of classes and the main page. Case 2 Changing to the package root directory: This is useful for documenting individual source files from different subpackages off the same root. Change to the package root directory, and supply the source files with paths from the root. example% cd /home/src/ example% javadoc -d /home/html java/awt/Button.java \ java/applet/Applet.java This example generates HTML-formatted documentation for the classes Button and Applet. Case 3 From any directory: In this case, it does not matter what the current directory is. Run javadoc, supplying the absolute path (or path relative to the current directory) to the .java files you want to document: example% javadoc -d /home/html /home/src/java/awt/Button.java \ /home/src/java/awt/Graphics*.java This example generates HTML-formatted documentation for the class Button and classes beginning with Graphics. Documenting Both Packages and Classes You can document entire packages and individual classes at the same time. Here is an example that mixes the two previous examples. You can use -sourcepath for the path to the packages but not for the path to the individual classes: example% javadoc -d /home/html -sourcepath /home/src java.awt \ /home/src/java/applet/Applet.java This example generates HTML-formatted documentation for the package java.awt and class Applet. (javadoc determines the package name for Applet from the package declaration, if any, in the Applet.java source file.) Real World Example javadoc has many useful options, some of which are more commonly used than others. Here is effectively the command you need to run javadoc on the Java platform API, using makefile variables (except not all packages to be documented are listed): example% javadoc -sourcepath /jdk/src/share/classes /* Path for source files */ -d /jdk/build/api /* Destination directory */ -use /* Adds "Use" files */ -splitIndex /* Splits index A-Z */ -windowtitle $(WINDOWTITLE) /* Adds a window title */ -doctitle $(DOCTITLE) /* Adds a doc title */ -header $(HEADER) /* Adds running header text */ -bottom $(BOTTOM) /* Adds text at bottom */ -group $(GROUPCORE) /* Core heading for overview page */ -group $(GROUPEXT) /* Ext heading for overview page */ -overview $ (SCRDIR) /overview.html /* For overview text */ -J-Xmx180m /* For 180MB memory */ java.lang java.lang.reflect /* Packages to document */ java.util java.io java.net java.applet WINDOWTITLE = 'Java Platform 1.2 Final API Specification' DOCTITLE = 'Java<sup><font size="-2">TM</font></sup> Platform 1.2 \ Final API Specification' HEADER = '<b>Java Platform 1.2</b><br><font size="-1">Final</font>' BOTTOM = '<font size="-1"><a href="http://java.sun.com/cgi-bin/\ bugreport.cgi">Submit a bug or feature</a><br><br>Java \ is a trademark or registered trademark of Sun \ Microsystems, Inc. in the US and other countries.<br>\ Copyright 1993-1998 Sun Microsystems, Inc. 901 San \ Antonio Road,<br>Palo Alto, California, 94303, U.S.A.\ </font>' GROUPCORE = '"Core Packages" "java.*:com.sun.java.*:org.omg.*" GROUPEXT = '"Extension Packages" "javax.*"' SRCDIR = '/java/jdk/1.2/src/share/classes' If you omit the -windowtitle option, javadoc copies the doc title to the window title. The -windowtitle option would not be needed except that the doc title contains HTML tags (which would appear as raw text in the window title). If you omit the -footer option, as done here, javadoc copies the header text to the footer. Other important options not needed in this example are -classpath and -link. ENVIRONMENT VARIABLES
CLASSPATH Environment variable that provides the path that javadoc uses to find user class files. This environment variable is overridden by the -classpath option. Separate your directories with a colon, as for example: .:/Users/vlh/classes:/Users/Shared/classes SEE ALSO
javac(1), java(1), jdb(1), javah(1), javap(1) See (or search java.sun.com) for the following: The Javadoc Home Page @ http://java.sun.com/products/jdk/javadoc/index.html Javadoc Enhancements @ http://java.sun.com/j2se/1.4/docs/tooldocs/javadoc/index.html Javadoc FAQ @ http://java.sun.com/products/jdk/javadoc/faq.html How to Write Doc Comments for Javadoc @ http://java.sun.com/products/jdk/javadoc/writingdoccomments.html How Classes Are Found @ http://java.sun.com/j2se/1.4/docs/tooldocs/findingclasses.html#srcfiles 14 July 2000 javadoc(1)