java cracking

Well JD andDJ Java 3.11.95(2009) with JAD Jad 1.5.8g(2001).7z is nice to see what's going on in the code.
When you just like to do some little magic - compiling the whole class file is often really painful, error prune or even not possible since there are to many errors / missing classes or whatever problems...

Before I open the *.class in IDA(enable in option/Disam/opcode byte=3) and a hexeditor. And wow the
CCK (Class Construction Kit)was a real revelation to me and exactly what I was looking for !!!
http://bcel.sourceforge.net/cck2_2.gif
(^As long as the [img] tag is not working here. you need the click")
Beside modifying the bytecode (That JBE also does) you can also delete or add lines and when doing so CCK also takes care about updating jmp and goto references.

Installation took me some time because I just downloaded BCEL.jar and tried to figure out how to run it. Well DL
http://bcel.sourceforge.net/downloads/BCEL.jar and
http://bcel.sourceforge.net/downloads/cck.jar
and then run it with
java.exe -jar cck.jar

Btw. if you like associate *.jar with javaw.exe like this. Well you can do it the clicky-clicky-way or in like this <windowskey+run>"cmd"<Enter>

>assoc .jar
.jar=WinRAR  <-wuups :D

>assoc .jar=jar_file
>ftype jar_file=%ProgramFiles%\Java\jdk1.6.0_26\jre\bin\javaw.exe -jar "%1"