The BCEL project (for Java bytecode manipulation) seems to be inactive. The site suggests looking at ObjectWeb's ASM project. ASM has nice Eclipse plug-in.
... until the collector arrives ...
This "blog" is really just a scratchpad of mine. There is not much of general interest here. Most of the content is scribbled down "live" as I discover things I want to remember. I rarely go back to correct mistakes in older entries. You have been warned :)