Question

我正在学习Java，不知怎的，我进入了AspectJ。我尝试从教程书中执行此代码：

    pointcut adviceExecutionPointcut( ) : adviceexecution( );

   // Advice declaration
   before( ) : adviceExecutionPointcut( )
      && !within(AdviceExecutionRecipe +)
   {
      System.out.println(
         "------------------- Aspect Advice Logic --------------------");
      System.out.println("In the advice picked by ExecutionRecipe");
      System.out.println(
         "Signature: "
            + thisJoinPoint.getStaticPart( ).getSignature( ));
      System.out.println(
         "Source Line: "
            + thisJoinPoint.getStaticPart( ).getSourceLocation( ));
      System.out.println(
         "------------------------------------------------------------");
   }
}

它以某种方式给了我这样的错误。

Exception in thread "main" java.lang.StackOverflowError
    at helloWorld.ajc$before$helloWorld$2$5e65e204(helloWorld.aj)
    at helloWorld.ajc$before$helloWorld$2$5e65e204(helloWorld.aj)
    at helloWorld.ajc$before$helloWorld$2$5e65e204(helloWorld.aj)
    at helloWorld.ajc$before$helloWorld$2$5e65e204(helloWorld.aj)
    at helloWorld.ajc$before$helloWorld$2$5e65e204(helloWorld.aj)

作为参考，这是示例代码和建议代码。

public class myClass {

    public void foo(int number, String name){
        System.out.println("Inside foo(int, String)");
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
    myClass myObject = new myClass();
    myObject.foo(1, "ican");

    }


public aspect helloWorld {
    public int a;
    long startTime;


    pointcut callPointcut(int value, String name) :
        call(* myClass.foo(int, String)) && args(value,name);

     before(int value, String name) : callPointcut(value,name)
       {
         startTime = System.nanoTime();
          System.out.println("Start Time in ns :" + startTime);
       }

任何帮助将不胜感激。感谢

Answer 1

我没有看到包含adviceexecution切入点的方面的类型声明？我怀疑你把这个建议块放到你的helloWorld方面。您获得递归stackoverflow的原因是因为建议适用于自身。警卫!within(AdviceExecutionRecipe +)旨在阻止适用于自己的建议。但是，您无法将其从AdviceExecutionRecipe更改为helloWorld，因为它不会适用于您的任何建议。所以我会在另一个方面保留该建议块，并将其命名为AdviceExecutionRecipe。有了这个，它对我有用：

$ ajc -1.8 *.java -showWeaveInfo

Join point 'adviceexecution(void helloWorld.ajc$before$helloWorld$1$68d3c671(int, java.lang.String))' in Type 'helloWorld' (helloWorld.java:9) advised by before advice from 'AdviceExecutionRecipe' (AdviceExecutionRecipe.java:5)

Join point 'method-call(void myClass.foo(int, java.lang.String))' in Type 'myClass' (myClass.java:10) advised by before advice from 'helloWorld' (helloWorld.java:9)

$ java myClass

------------------- Aspect Advice Logic --------------------
In the advice picked by ExecutionRecipe
Signature: void helloWorld.before(int, String)
Source Line: helloWorld.java:9
------------------------------------------------------------
Start Time in ns :216368803494701
Inside foo(int, String)

在DOMJ中，adviceexecution（）无效

1 个答案: