Total javassist/bytecode newbie here. I'm writing a program to list bytecode instructions from a classfile, akin to what "javap -c -p CLASSFILE" gives you. Somthing like:
0: aload_0
1: invokespecial #15; //Method java/lang/O
4: aload_0
5: ldc2_w #16; //double 99.0d
8: putfield #19; //Field size:D
This snippet from the tutorial lists the index & opcodes but no operands:
CodeIterator ci = ... ;
while (ci.hasNext()) {
int index = ci.next();
int op = ci.byteAt(index);
System.out.println(index + ": " +Mnemonic.OPCODE[op]);
}
Result of this code is something like:
0: aload_0
1: invokespecial <--no operand!!!
4: aload_0
5: ldc2_w <--no operand!!!
The "hasNext" call seems to move the iterator to the next opcode, skipping past operands. So how do I parse out operands for things like control flow or method call opcodes? Since # of operands varies based on the particular opcode, is there an easy way to know how many bytes to parse out per instruction?
