https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.javadoc;


This is an example of a starting class for a doclet, showing the entry-point methods. A starting class must import com.sun.javadoc.* and implement the start(RootDoc) method, as described in the package
description. If the doclet takes command line options, it must also implement optionLength and validOptions. 
 A doclet supporting the language features added since 1.1 (such as generics and annotations) should indicate this by implementing languageVersion. In the absence of this the doclet should not invoke any of the Doclet API methods added since 1.5, and the results of several other methods are modified so as to conceal the new constructs (such as type parameters) from the doclet. 
 To start the doclet, pass -doclet followed by the fully-qualified name of the starting class on the javadoc tool command line. 
Deprecated: The declarations in this package have been superseded by those in the package jdk.javadoc.doclet. For more information, see the Migration Guide in the documentation for that package.
/**
 * This is an example of a starting class for a doclet,
 * showing the entry-point methods.  A starting class must
 * import com.sun.javadoc.* and implement the
 * {@code start(RootDoc)} method, as described in the
 * <a href="package-summary.html#package.description">package
 * description</a>.  If the doclet takes command line options,
 * it must also implement {@code optionLength} and
 * {@code validOptions}.
 *
 * <p> A doclet supporting the language features added since 1.1
 * (such as generics and annotations) should indicate this
 * by implementing {@code languageVersion}.  In the absence of
 * this the doclet should not invoke any of the Doclet API methods
 * added since 1.5, and
 * the results of several other methods are modified so as
 * to conceal the new constructs (such as type parameters) from
 * the doclet.
 *
 * <p> To start the doclet, pass
 * {@code -doclet} followed by the fully-qualified
 * name of the starting class on the javadoc tool command line.
 *
 * @deprecated
 *   The declarations in this package have been superseded by those
 *   in the package {@code jdk.javadoc.doclet}.
 *   For more information, see the <i>Migration Guide</i> in the documentation for that package.
 */
@Deprecated(since="9", forRemoval=true)
@SuppressWarnings("removal")
public abstract class Doclet {

    
Generate documentation here.
This method is required for all doclets.

Params:
  • root – Supply the RootDoc to the method.
Returns:true on success.
/**
     * Generate documentation here.
     * This method is required for all doclets.
     *
     * @param root Supply the RootDoc to the method.
     * @return true on success.
     */
    public static boolean start(RootDoc root) {
        return true;
    }

    
Check for doclet-added options.  Returns the number of
arguments you must specify on the command line for the
given option.  For example, "-d docs" would return 2.


This method is required if the doclet contains any options.
If this method is missing, Javadoc will print an invalid flag
error for every option.

Params:
  • option – the option for which the number of arguements is returned.
Returns:number of arguments on the command line for an option
        including the option name itself.  Zero return means
        option not known.  Negative value means error occurred.
/**
     * Check for doclet-added options.  Returns the number of
     * arguments you must specify on the command line for the
     * given option.  For example, "-d docs" would return 2.
     * <P>
     * This method is required if the doclet contains any options.
     * If this method is missing, Javadoc will print an invalid flag
     * error for every option.
     *
     * @param option the option for which the number of arguements is returned.
     * @return number of arguments on the command line for an option
     *         including the option name itself.  Zero return means
     *         option not known.  Negative value means error occurred.
     */
    public static int optionLength(String option) {
        return 0;  // default is option unknown
    }

    
Check that options have the correct arguments.


This method is not required, but is recommended,
as every option will be considered valid if this method
is not present.  It will default gracefully (to true)
if absent.


Printing option related error messages (using the provided
DocErrorReporter) is the responsibility of this method.

Params:
  • options – Supply valid options as an array of Strings.
  • reporter – The DocErrorReporter responsible for these options.
Returns:true if the options are valid.
/**
     * Check that options have the correct arguments.
     * <P>
     * This method is not required, but is recommended,
     * as every option will be considered valid if this method
     * is not present.  It will default gracefully (to true)
     * if absent.
     * <P>
     * Printing option related error messages (using the provided
     * DocErrorReporter) is the responsibility of this method.
     *
     * @param options Supply valid options as an array of Strings.
     * @param reporter The DocErrorReporter responsible for these options.
     * @return true if the options are valid.
     */
    public static boolean validOptions(String options[][],
                                       DocErrorReporter reporter) {
        return true;  // default is options are valid
    }

    
Return the version of the Java Programming Language supported
by this doclet.


This method is required by any doclet supporting a language version
newer than 1.1.

Returns: the language version supported by this doclet.
Since:1.5
/**
     * Return the version of the Java Programming Language supported
     * by this doclet.
     * <p>
     * This method is required by any doclet supporting a language version
     * newer than 1.1.
     *
     * @return  the language version supported by this doclet.
     * @since 1.5
     */
    public static LanguageVersion languageVersion() {
        return LanguageVersion.JAVA_1_1;
    }
}