Java - Adding references to Framework API Documentation (docs) while generating Javadocs

In continuation to my earlier posts about using Maven to generate Javadocs for your project source code, I want to provide some inputs on how you can link your project's generated apiDocs to the apiDocs of the framework it is dependent on. In my case, I was working on an ATG project and used Maven javadoc plugin to generate javadocs for my project source code, the apiDocs got generated successfully but all the ATG Framework classes that my project source code referred to were linked to the Oracle java documentation. This was because the javadoc plugin assumes that any class thats not defined in the project source code is actually a java class. To avoid this from happening, you can add links/link tag combination (as given in the snippet below) and point the same to the folder/URL which contains the apiDocs/package-list (in my case this file was inside the folder mentioned in the link tag) file. This file helps the javadoc utility understand as to which packages are covered by the docs provided by the folder in the link tag. This way if your project is referring to multiple frameworks you can download the framework documentation to a folder and add the offline links to the javadoc plugin configuration section and rerun the maven command to regenerate the apiDocs with the updated links.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-javadoc-plugin</artifactId>
    <version>2.8</version>
    <configuration>
        <reportOutputDirectory>C:/Project/apiDocs</reportOutputDirectory>
        <doclet>org.umlgraph.doclet.UmlGraphDoc</doclet>
        <docletArtifact>
            <groupId>org.umlgraph</groupId>
            <artifactId>doclet</artifactId>
            <version>5.1</version>
        </docletArtifact>
        <additionalparam>-views</additionalparam>
        <useStandardDocletOptions>true</useStandardDocletOptions>
        <links>
            <link>file:///C:/Users/nseshadr/Downloads/E22630_01/Platform.1002/apidoc</link>
        </links>
    </configuration>
    <executions>
        <execution>
            <id>aggregate</id>
            <goals>
                <goal>aggregate</goal>
            </goals>
        </execution>
    </executions>
</plugin>

You can always refer to the Maven Javadoc Plugin page for more information and options.

Note: Also you can download the Oracle Sun Java API documentation and add information about the same to the links/link section and that will make all your java class references point to the local API folder as against the internet URL.