How to write javadoc links?

Question

How do I write links into javadocs?

Currently, I have something like:

{@link java.lang.Math#sqrt(double) Math.sqrt}

to produce the text Math.sqrt that should link to the java.lang.Math.sqrt(double) API, however, all it does is produce the text, no link.

Answer 1

To get a link to something external to your code, you need use the -linkoffline option

where the -linkoffline option has the format something like this (artificially wrapped):

-linkoffline http://java.sun.com/javase/6/docs/api/
             http://java.sun.com/javase/6/docs/api/

This tells the JavaDoc tool where to find the link to the JavaDoc and for what packages to use that link. From the 2nd URL, it will append "package-list" to load the actual URL:

http://java.sun.com/javase/6/docs/api/package-list

which you can verify by loading it in a browser does contain the list of packages documented at that JavaDoc URL. This tells the JavaDoc tool that any @link references to anything in one of those packages should link to the provided URL.

Answer 2

My answer is very much provided by Eddie, but his exact code doesn't work for me (or at least when using the version of javadoc that comes with Java 1.6)

If I do:

    javadoc -linkoffline http://java.sun.com/javase/6/docs/api/ 
                         http://java.sun.com/javase/6/docs/api/package-list
            -public FileName.java

then javadoc complains:

    javadoc: warning - Error fetching URL: 
    http://java.sun.com/javase/6/docs/api/package-list/package-list

If, on the other hand, I do:

    javadoc -linkoffline http://java.sun.com/javase/6/docs/api/ 
                         http://java.sun.com/javase/6/docs/api/ 
            -public FileName.java

Then it works, and my links are populated as I want them to be.

Additionally, my link isn't malformed. The text {@link java.lang.Math#sqrt(double) Math.sqrt} produces the link text Math.sqrt instead of the default Math.sqrt(double).

Answer 3

This document might be of assistance, remember that for @link you need to use the URL for the doc you are linking to.