Support for generics (added in Java 5) is something that was sorely lacking from the Java code completion in RSTALanguageSupport. That is, until the latest Subversion changes! This is a very early implementation, and like a lot of the recent Java support changes, there may be bugs and performance issues. But it’s there! And things look good for simple usage of the java.util Collecitons classes:
Previously, methods such as List#add() and List#get() would always say that their parameter/return types were of type Object. Now, if you specify type arguments to classes that accept them, code completion will reflect those type arguments.
As before, please be bleeding edge, try this out, and report back bugs! You can do so either here, or in the RSyntaxTextArea forums. There is also currently no way to turn this feature off (i.e. if you want to program with “-source 1.4″ effectively enabled), but that will come soon.