I tried in Eclipse to use
org.apache.commons.lang.NotImplementedException, though it seems from what I can see both from IntelliSense and the Package Explorer, that that namespace does not exist.
So I guess I must load some other package(do you call them libraries in java?) than those it loaded by default.
This is my current setup: (link dead)
You need to add Apache commons jar file to the project. You can select the jar you want from here – http://commons.apache.org/downloads/index.html
for lang you need this – commons-lang-2.5.jar