Bytecode changes from SE1.4 to SE5

[alebu]

As I know, java .class file specification was unchanged
until version 1.4 but because of new features in version 5 ( autoboxing, enums, ... ) there was discution about changes in java bytecode specification. I found JSR 201

http://www.jcp.org/en/jsr/detail?id=201

and it seems that specs WAS changed, but what about compatibility with old code? I saw somewhere ( on IBM site I think, but not sure ) that there was some compromise beetwin new specs and old, so I am wonder what was those compromises?

 

[Diancecht]

I seriously doubt that backwards compatibility is not maintained at bytecode level, that would not be serious at all. That would mean that all "old" applications in production stage need to be recompiled.

Cheers,
Dian

 

[alebu]

I just remember that in some article on IBM site I saw somethink about the reasons why SE5 generics are not so cool as they could be. It was some compatibility reason as I understood, so if specs WAS changed, then compatibility is already broken and there is no need to worry about it. But there is JSR-201 and it is about that changes, so I probably miss somethink. Thats why I asking about it, hovewer, it is not a question of life and dead. I just wonder ...