import org.objectweb.asm.*;
public class MyClassTransformer extends ClassVisitor {
public MyClassTransformer(ClassVisitor cv) {
super(Opcodes.ASM9, cv);
}
@Override
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions);
return new MyMethodTransformer(mv);
}
}
class MyMethodTransformer extends MethodVisitor {
public MyMethodTransformer(MethodVisitor mv) {
super(Opcodes.ASM9, mv);
}
@Override
public void visitCode() {
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
mv.visitLdcInsn("Hello, ASM!");
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
super.visitCode();
}
}
<dependency>
<groupId>org.ow2.asm</groupId>
<artifactId>asm</artifactId>
<version>9.2</version>
</dependency>
