Java Assembly Language There is currently no standard syntax for representing Java bytecodes in human-readable form. Sun's javap utility provides one representation, but its output is complicated by code offsets and constant pool index numbers. Thus, a simpler syntax of coding in Java bytecodes was created.
Note: This is documentation on the syntax only. To understand what the operands mean and their usage in programming, look at the Java Virtual Machine Specification. Most of the documentation is beta, meaning some of it is out-of-date. Look for the book by Tim Lindholm and Frank Yellin (to be available sometime this summer by Addison-Wesley) for the latest documentation. Excerpts are available at the above link.