ASM Kullanımı - Insturmentation

Giriş

Açıklaması şöyle

ASM is a widely-used bytecode manipulation library. It provides a comprehensive API for analyzing and modifying bytecode. ASM operates at a low level, giving developers fine-grained control over bytecode manipulation.

Örnek

Şöyle yaparız

import org.objectweb.asm.*;

public class ASMExample {
  public static void main(String[] args) throws Exception {
    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
    cw.visit(Opcodes.V11, Opcodes.ACC_PUBLIC, "com/example/Calculator", null,
  "java/lang/Object", null);
        
    MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "add", "(II)I", null, null);
    mv.visitCode();
    mv.visitVarInsn(Opcodes.ILOAD, 1);
    mv.visitVarInsn(Opcodes.ILOAD, 2);
    mv.visitInsn(Opcodes.IADD);
    mv.visitInsn(Opcodes.IRETURN);
    mv.visitMaxs(2, 3);
    mv.visitEnd();
        
    cw.visitEnd();
        
    byte[] bytecode = cw.toByteArray();
        
    // Use the generated bytecode...
  }
}