issues in deploying compiled war with jdk 1.5 and deploying in jdk 1.6 environment (which is weblogic 10gR3)

Question

just curious to know issues in deploying compiled war with jdk 1.5 and deploying in jdk 1.6 environment (which is weblogic 10gR3)

Answer 1

Java 1.6 is backwards compatible with Java 1.5.

A showstopper may however be the ExecutorService#invokeAll() methods. The compiled version of the Java 1.5 code will work in Java 1.6 runtime, but wherever the aforementioned methods are used, the Java 1.5 source code will not be compileable for 1.6 due to a change in the generics in the declared methods. In 1.5 the Collection argument is declared as Collection<Callable<T>> while in 1.6 this argument is extended to Collection<? extends Callable<T>>.

You'll have to either develop for specifically 1.5 and then just run on 1.6, or to change the code to comply 1.6 and then both develop and run for 1.6. But if you aren't using those methods, then there is in fact nothing to worry about.