Hotswapping classes throws an IllegalStateException about byte-buddy

[raphw]

Thanks for reporting this. You are right, this is required by an ASM adapter I am using which has this requirement without documenting it. I am not yet sure when I have time to look at it. The easiest is to redefine the class itself instead of renaming it:

Foo foo = new Foo();
new ByteBuddy()
  .redefine(Bar.class)
  .method(named("m")).intercept(FixedValue.value("bar")) 
  .make()
  .load(Foo.class.getClassLoader(), classLoadingStrategy);
System.out.println(foo.m());

I will however fix this on the long run once I have taken care of more pressing problems with 0.7.

[Anon10W1z]

On a side note, is there any way to modify the class that an existing class extends from?

[raphw]

No there is not and this is by design. Byte Buddy is designed with binary compatible instrumentation in mind. You would rather create a new class that subclasses the desired subclass for implementing the desired class.

[Anon10W1z]

Alright, thank you for your help. I definitely love this library regardless!

[raphw]

Thank you. All the class swapping functionality is not used by too many people but I hope that these features become more useful with the evolution of the JVM.

For the reported error: The ASM library could actually work with the non-expanded frames. The remapper that I use is rather generic in its functionality which is why they require it. The easiest would however be to not require the expansion for simple use cases. I filed a bug with ASM and I hope that they will take it. Otherwise, I need to craft some sort of work-around in the future.

[raphw]

I leave the issue open until it no longer fails.

[Anon10W1z]

Oh right, my bad sorry.

[raphw]

No problem. Again, thanks for reporting.

[raphw]

I resolved this issue on master with a workarround that works for Byte Buddy's use case. At best, ASM will offer support for this out-of-the-box at some point. Since the 0.7 release has gone wrong, I reverted master to a stable non-generic version for now and will release a version 0.6.13 some time soon.

[raphw]

0.6.13 is released where this should be fixed.