我有以下奇怪的行为。
当我使用命名切入点时，建议方法在@AfterThrowing带注释方法的主体之前运行。但是，如果使用内联切入点，则首先运行带注释的@AfterThrowing。
为什么这样？
这是代码：
@Component
@Aspect
public class CustomAspect {
@AfterThrowing(pointcut = "execution(* throwAnException(..))", throwing = "exception")
public void adviceForExceptionThrowing(Exception exception) {
System.out.println("###### " + exception.getMessage() + " ######");
}
}
结果是：
INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@5a10411: startup date [Wed Jun 14 15:51:26 EEST 2017]; root of context hierarchy
###### Some message from the exception ######
Exception in thread "main" java.lang.Exception: Some message from the exception
第二结果：
@Component
@Aspect
public class CustomAspect {
@Pointcut("execution(* throwAnException(..))")
private void pointcutForException() {
}
@AfterThrowing(pointcut = "pointcutForException()", throwing = "exception")
public void adviceForExceptionThrowing(Exception exception) {
System.out.println("###### " + exception.getMessage() + " ######");
}
}
我们得到：
INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@5a10411: startup date [Wed Jun 14 15:54:38 EEST 2017]; root of context hierarchy
Exception in thread "main" java.lang.Exception: Some message from the exception
at blog.codingideas.aspects.SomeBean.throwAnException(SomeBean.java:13)
at blog.codingideas.aspects.SomeBean$$FastClassBySpringCGLIB$$97c62a5f.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:62)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
at blog.codingideas.aspects.SomeBean$$EnhancerBySpringCGLIB$$985c5826.throwAnException(<generated>)
at blog.codingideas.ApplicationMain.main(ApplicationMain.java:13)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
###### Some message from the exception ######
最佳答案
您的代码按预期工作。引发异常后，将执行@AfterThrown建议。
棘手的是使用System.out.println。它在后台调用PrintStream。这是一个缓冲的流。缓冲流填满后或显式调用flush时，会将其写入输出（控制台）。
因此，在您的情况下，这取决于内部动态情况，即在其他线程打印的异常stacktrace之前，堆栈已被填满多少以及能够执行多少个打印语句。
附言尝试几次运行每个解决方案，您会发现###### Some message from the exception ######在主堆栈跟踪之前和之后以随机顺序打印。