I thought Java had short circuit evaluation, yet this line is still throwing a null pointer exception:
if( (perfectAgent != null) && (perfectAgent.getAddress().equals(entry.getKey())) ) {
In this case perfectAgent is null, so I just want the whole expression to return false, but my app is still crashing on this line with a NullPointerException.
EDIT, general response:
Since perfectAgent is null, nothing to the right of the && should be executed, as it is impossible for the expression to be true. More to the point, it is impossible to execute perfectAgent.getAddress() since perfectAgent does not contain a valid reference (it being null and all). I'm trying to use short circuit evaluation to not have to check for null in a seperate statement as that makes the logic more sloppy.
EDIT 2 (or, I'm an idiot): Yeah, like many things in life you figure out the answer right after announcing to the world that you're a moron. In this case, I had turned off Eclipse's autobuild while doing something else and not turned it back on, so I was debugging class files that didn't match up with my source.
Advanced debugging lesson #1:
If you run into a seemingly impossible error (e.g. one that contradicts you knowledge about Java), do the following:
Consult a reputable text book (or better still, the relevant standard) to confirm that your understanding is not flawed. (In this case your understanding was correct, and any half-decent textbook would confirm this in a minute.)
Check all of the stupid things that you could have done that could cause the impossible error. Things like not saving a file, not doing a complete build, running an old / stale version of the application, being in the wrong directory, and so on.
In summary, learn to doubt yourself a bit more.