小编4ev*_*one的帖子

我正在尝试在发生某些特定异常时添加一些监控.例如,如果我有这样的方面:

@Aspect
public class LogAspect {

  @AfterThrowing(value = "execution(* *(..))", throwing = "e")
  public void log(JoinPoint joinPoint, Throwable e){
    System.out.println("Some logging stuff");
  }
}

和测试类:

 public class Example {


  public void divideByZeroWithCatch(){
    try{
      int a = 5/0;
    }
    catch (ArithmeticException e){
      System.out.println("Can not divide by zero");
    }
  }

  public void divideByZeroWithNoCatch(){
    int b = 5/0;
  }

  public static void main (String [] args){
    Example e = new Example();
    System.out.println("***** Calling method with catch block *****");
    e.divideByZeroWithCatch();
    System.out.println("***** Calling method without …

有没有办法在我有一个方面必须在其逻辑中使用一些复杂的实例化服务的情况下使用 Guice 和 AspectJ ？

例如：

@Aspect
public class SomeAspect {

  private final ComplexServiceMangedByGuice complexServiceMangedByGuice;

  @Inject
  public SomeAspect(ComplexServiceMangedByGuice complexServiceMangedByGuice){
    this.complexServiceMangedByGuice = complexServiceMangedByGuice;
  }

  @AfterThrowing(value = "execution(* *(..))", throwing = "e")
  public void afterThrowingException(JoinPoint joinPoint, Throwable e){
    complexServiceMangedByGuice.doSomething(e);
  }
}

如果我尝试像示例中那样（使用方面构造函数），我的方面将不会被调用。如果我尝试注入字段（没有定义方面构造函数），方面将被调用，但字段complexServiceMangedByGuice不会被设置。我发现的一个解决方案是在建议方法主体中获取实例，因此一个方面将如下所示：

@Aspect
public class SomeAspect {

private static ComplexServiceManagedByGuice complexServiceManagedByGuice;

  @AfterThrowing(value = "execution(* *(..))", throwing = "e")
  public void afterThrowingException(JoinPoint joinPoint, Throwable e){
    if(complexServiceManagedByGuice == null){
    Injector injector = Guice.createInjector(new ModuleWithComplexService());
    complexServiceMangedByGuice = injector.getInstance(ComlexServiceManagedByGuice.class);
    }
    complexServiceMangedByGuice.doSomething(e);
  }
}

但这会带来一些不良的开销。