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copied!<p>Serious answer.</p> <p>I'd auto-generate Java code and use the Java compiler to generate the class file. This look a lot easier then battling BCEL. At least because it's easier to code an algorithm in a 'higher' language than in Java Byte Code.</p> <p>Any other programming language that produces byte code will do aswell, but i guess Java is one of the easiest approaches.</p> <p>And coming to your questions,</p> <p>(1) Yes, some metadata is pretty static. Wikipedia has a nice overview of the <a href="http://en.wikipedia.org/wiki/Class_(file_format)" rel="nofollow noreferrer">class file format</a></p> <p>(2) Yes, the classfile is 'binary'. There is no <em>alphanumerical</em> language (like assembler) for java bytecode (at least I haven't heard of any such tool, javap can print bytecode readable but there's no way back)</p> <p><strong>Edit</strong></p> <p>Still hard to guess, what you really want to do, but just in case, you want to write a classfile around an arithmetic expression that can evaluate that arithmetic expression in a java virtual machine, then you really could start with creating a template class file.</p> <p>In that case I'd code this 'evaluator' in Java and test it until it evaluates all valid inputs. I'd use a private field to hold the expression, initialised with a dummy expression.</p> <p>The classfile of my Java coded evaluator would be a perfect template for the 'dynamic' class generation - I just had to find out how to 'replace' the dummy expression with a real one, recreate valid classfile (you may have to adjust some pointers because of different string lengths) and it should work.</p> <p>Even if this guess is totally wrong, it may serve as case study and may help you on your way :)</p>

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