調用攔截器的超類方法bytebuddy

Question

我們有一個模糊的類，我們需要使用bytebuddy進行增強。我們基本上需要重新定義一種方法。子類似乎沒有奏效（代碼沒有執行）。重新啓動工作，但在我們攔截的方法中，我們需要調用超類（現在像在「繼承」中講超類）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

如果我明白你的正確，你只想攔截一個方法調用，如果它是從你的類外部調用，但不是從內部調用。

這是一件很難實現的事情。 Byte Buddy允許您向任何類添加代碼，但即使手動添加代碼也很難編碼。

你最好的機會是可能添加一個線程本地存儲來標記這樣的自我調用，並檢測它是否攔截器被再次命中，你只需將其委託給super方法而不應用攔截器邏輯。