调用拦截器的超类方法bytebuddy

Question

我们有一个模糊的类，我们需要使用bytebuddy进行增强。我们基本上需要重新定义一种方法。子类似乎没有奏效（代码没有执行）。重新启动工作，但在我们拦截的方法中，我们需要调用超类（现在像在“继承”中讲超类）方法。

class Parent { 
    public void connect(){ 
    ... 
    }; 
} 

class WeNeedToHackThis extends Parent { 
    public void connect(InetAddress addr){ 
     //... this is what we want to hack 
    } 
    public void connect(){ 
     this.connect(null); 
     // this is getting called from interceptor :(which delegates to our hacked method 
     // we need to call "real" superclass's (Parent) method instead 
    } 

} 
... 
Class<?> dynamic = new ByteBuddy() 
      .with(TypeValidation.DISABLED) 
      .rebase(commandBase, locator) 
      .method(named("connect").and(takesArgument(0, InetAddress.class))) 
      .intercept(MethodDelegation.to(Session3270ConnectMethod.class)) 
      .make() 
      .load(Thread.currentThread().getContextClassLoader(), ClassLoadingStrategy.Default.INJECTION) 
      .getLoaded(); 

//In our interceptor: 
    public static void connect(InetAddress paramInetAddress, 
      @Origin Method origin, 
      @This Object self) throws SessionException { 
     try { 
      System.out.println("hi from hijacked"); 
      c.call(); 
      //HOW DO WE CALL SOMETHING LIKE super.connect() 
      // we need to call Parent.connect(); 
      // but I am stuck at how to access superclass code (new Parent().connect(). 
      // I cant access the Parent class method calls on this object 
      // if I use @SuperCall or @This then I am getting already overriden version, I need to call the super (Parent's.class) version :(

     } catch (Exception e) { 
      throw new RuntimeException(e); 

     } 
    } 

Answer 1

public static void connect(InetAddress paramInetAddress, 
      @Super Object parentObj, @This Object myself, @SuperCall Callable<?> call) throws SessionException { 
     try { 
      System.out.println("hi from hijacked"); 
      parentObj.getClass().getMethods(); 
      Field IMPL_LOOKUP = MethodHandles.Lookup.class.getDeclaredField("IMPL_LOOKUP"); 
      IMPL_LOOKUP.setAccessible(true); 
      MethodHandles.Lookup lkp = (MethodHandles.Lookup) IMPL_LOOKUP.get(null); 
      MethodHandle h1 = lkp.findSpecial(b.class, "connect", MethodType.methodType(void.class), Session3270.class); 
      h1.invoke(myself); 
     } catch (Throwable e) { 
      throw new RuntimeException(e); 

     } 
    } 

Answer 2

如果我明白你的正确，你只想拦截一个方法调用，如果它是从你的类外部调用，但不是从内部调用。

这是一件很难实现的事情。 Byte Buddy允许您向任何类添加代码，但即使手动添加代码也很难编码。

你最好的机会是可能添加一个线程本地存储来标记这样的自我调用，并检测它是否拦截器被再次命中，你只需将其委托给super方法而不应用拦截器逻辑。