java - 用 ByteBuddy 修饰方法

Question

如何定义一个方法，然后用 ByteBuddy 装饰它(多次)？这是我的例子

Builder<Object> builder = new ByteBuddy().subclass(Object.class).name("Dynamic");
    builder = builder.defineMethod("method", void.class, Visibility.PUBLIC)
    .intercept(MethodDelegation.to(new Object(){
        
        @RuntimeType
        public void intercept(@This Object o) {
            System.out.println("Executing code...");
        }
        
    }));
    
    builder = builder.method(ElementMatchers.named("method")).
    intercept(MethodDelegation.to(new Object(){
        
        @RuntimeType
        public void intercept(@This Object o) {
            System.out.println("Executing other code...");
        }
        
    }));
    
    try {
        Class cls = builder.make()
                .load(StructClassBuilder.class.getClassLoader())
                .getLoaded();
        
        Object obj = cls.newInstance();
        cls.getDeclaredMethod("method").invoke(obj, args);
    } catch (Exception e1) {
        e1.printStackTrace();
    }

输出为

Executing other code...

我希望输出是

Executing code...

Executing other code...

谢谢

Answer 1

一种选择是使用 MethodDelegation.to(...).addThen(...) 方法链接您的拦截器。

public class ByteBuddyTest {

  public static void main(String[] args) throws Exception {
    DynamicType.Builder<Object> builder = new ByteBuddy().subclass(Object.class).name("Dynamic");
    builder = builder
        .defineMethod("method", void.class, Visibility.PUBLIC)
        .intercept(MethodDelegation.to(Interceptor1.class).andThen(MethodDelegation.to(Interceptor2.class)));

    try {
        Class<?> clazz = builder.make().include().load(ByteBuddyTest.class.getClassLoader()).getLoaded();

        Object obj = clazz.newInstance();
        clazz.getDeclaredMethod("method").invoke(obj, args);
    } catch (Exception e1) {
        e1.printStackTrace();
    }
  }

  public static class Interceptor1 {

      public static void intercept() {
          System.out.println("Executing code...");
      }
  }

  public static class Interceptor2 {

      public static void intercept() {
          System.out.println("Executing other code...");
      }
  }
}