If you are fortunate enough to be using JDK 7, the newly available Objects class is the obvious (at least to me) choice for implementing the “common” Java object ...

I’ve used Java Architecture for XML Binding (JAXB) successfully for a wide set of problems and generally really like it. However, it is not without its downsides ...

It's not terribly clean, but you could use indexOf() and check if it returns -1. Better than breaking out a loop.