This plugin provides Javadoc links to the JDK 1.5 API. It uses a pre-built search index(using QDox and Apache Lucene).
[00:13] <The_Birdman> ~describe javadoc
[00:13] <jerkbot> Simple Javadoc search engine
[00:13] <The_Birdman> ~help javadoc
[00:13] <jerkbot> ~javadoc <class>|~javadoc <class>#method|~javadoc <class>#method(types)
[00:13] <The_Birdman> ~javadoc LoginContext
[00:13] <jerkbot> http://is.gd/2EeNG