java asm bytecode. jsr instruction sample.

CDump.java

import java.util.*;
import org.objectweb.asm.*;

public class CDump implements Opcodes {

	public static byte[] dump() throws Exception {

		ClassWriter cw = new ClassWriter(0);
		FieldVisitor fv;
		MethodVisitor mv;
		AnnotationVisitor av0;

		cw.visit(V1_1, ACC_PUBLIC, "C", null, "java/lang/Object", null);

		{
			mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
			mv.visitCode();
			mv.visitVarInsn(ALOAD, 0);
			mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
			mv.visitInsn(RETURN);
			mv.visitMaxs(1, 1);
			mv.visitEnd();
		}
		{
			mv = cw.visitMethod(0, "m", "()V", null, null);
			mv.visitCode();
			Label l0 = new Label();
			Label l1 = new Label();
			mv.visitTryCatchBlock(l0, l1, l1, null);
			Label l2 = new Label();
			Label l3 = new Label();
			mv.visitTryCatchBlock(l2, l3, l1, null);
			mv.visitInsn(ICONST_0);
			mv.visitVarInsn(ISTORE, 1);
			mv.visitLabel(l0);
			mv.visitIincInsn(1, 1);
			mv.visitJumpInsn(GOTO, l2);
			mv.visitLabel(l1);
			mv.visitVarInsn(ASTORE, 3);
			Label l4 = new Label();
			mv.visitJumpInsn(JSR, l4);
			mv.visitVarInsn(ALOAD, 3);
			mv.visitInsn(ATHROW);
			mv.visitLabel(l4);
			mv.visitVarInsn(ASTORE, 2);
			mv.visitIincInsn(1, -1);
			mv.visitVarInsn(RET, 2);
			mv.visitLabel(l2);
			mv.visitJumpInsn(JSR, l4);
			mv.visitLabel(l3);
			mv.visitInsn(RETURN);
			mv.visitMaxs(1, 4);
			mv.visitEnd();
		}
		cw.visitEnd();

		return cw.toByteArray();
	}
}