But it can't possibly be "necessary to make changes". If the app runs under Java 1.4, then it runs under Java 5, without any changes. To change code simply for the sake of using new language features seems dubious to me. I'd do that in those pieces of code that are being worked on in the future, or where it has an obvious functional benefit, but not for the sake of simply using new features.
Thanks a lot for the link, I found it really helpful and I will keep referring back to it for some time to come!
About the "necessary" changes part, ofcourse, although the code compiles without problems, there seem to be some better ways of doing things in java 1.5 and the project manager wanted to implement that. This is good for me anyway, as by doing this, I'm getting more familiar with the code(I'm new to this project).
If you compile this code and then disassemble it with javap, you will see that the code with the new style loop has fewer bytecode instructions (about 18 instructions for the old loop, 14 for the new loop). So in this case, the new loop would probably be faster than the old loop.
This is very interesting, I will bring this up with the manager and I definitely see the sense in what you are saying. Thanks!