What standard optimization refactoring can I do to my Java application?

Question

I have a semi big Java application. It's written quite poorly and I suspect there are quite a lot of simple things I can do that will clean things up a bit and improve performance.

For example I recently found the

String.matches(regex)

function used quite a lot in loops with the same regex. So I've replaced that with precompiled Patterns. I use FindBugs (which is great BTW) but that didn't spot this problem and I'm limited on tools that I can use here at work.

Is there anything else simple like this that I should look at?

Answer 1

Have a look at these differents tools:

• FindBugs (you already did it).
• Checkstyle
• PMD
• ...

I suggest also to have a look at Sonar, which is a great wrapper for all these tools.

All these tools are free!

Globally, they will not help you to improve the performance, but the quality of the code.