答案已经很老了，涉及编写很多代码。
从asm v5开始，打印方法说明很简单：
// Setup for asm ClassReader, ClassWriter and your implementation of the ClassVisitor(e.g.: YourClassVisitor)final ClassReader reader = new ClassReader(classBytes);final ClassWriter writer = new ClassWriter(classReader, ClassWriter.COMPUTE_MAXS);final ClassVisitor visitor =new YourClassVisitor(Oppres.ASM5, visitor);
在实现ClassVisitor时，只需覆盖visitMethod方法。这里是一个例子：
public class YourClassVisitor extends ClassVisitor { public InstrumentationClassVisitor(int api, ClassVisitor cv) { super(api, cv); } @Override public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) { MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions); Printer p = new Textifier(Oppres.ASM5) { @Override public void visitMethodEnd() { print(new PrintWriter(System.out)); // print it after it has been visited } }; return new TraceMethodVisitor(mv, p); }}TraceMethodVisitor将由classVisitor接收事件调用，以访问方法说明等。然后，TraceMethodVisitor将在打印机的帮助下打印代码。
