So guys,
I\'m trying to play a bit with Javac Cross compilation with Ant and on terminal. Locally and on an integration environment and i\'m having the same problem
You cannot have a newer version of source and lower version of target. For example, In Java 5, a number of new features were added to the language, such as generics, autoboxing and you cannot expect a JVM 1.4 to understand it. So, you must tell the compiler that your source code is Java 1.4 source code. This explains the results you have.
The default for -target depends on the value of -source:
For more info refer to http://docs.oracle.com/javase/7/docs/technotes/tools/windows/javac.html