Hi coldcrow
You can code in Java with Xcode, but in a separate forum one of Apple's Java developers said that it is now only meant for small scale Java projects. If you've already got some experience with Netbeans then you might do better to continue with Netbeans and don't worry about Xcode.
On a personal note, I used to be a keen on using Xcode for Java, but the support for the language declined over time, it never had a Java GUI designer, bits (like the debugger) stopped working properly, and projects that worked one day suddenly became deprecated and then stopped working. In the end, I lost patience with it and moved to Netbeans. I now have a collection of old Xcode Java projects dating back to 2004 that simply won't run any more; as and when I need to use them I now have to transfer them to Netbeans, and I wish I'd never started with Xcode. At least Netbeans is under continuous development and will always support Java.
If any reading that mini-rant you still want to continue with Xcode for Java then I'll wish you good luck!
Bob