Java Programming

I'm nearing completion of a project and as I'm not that experienced in software security. I was wondering what security considerations have to be made with Java applications, so far I've:

- Obfuscated the bytecode using Proguard.
- Prevented SQL injections by using prepared statements in all SQL querys.
- Used SSL for any sensitive data transfer.

Are there any other other obvious considerations that need to be made regarding the code. I suppose the above considerations are applicable to all code not just Java but is there anything I'm blatantly missing?

Thanks for the help!