Spring AOP基於註解的AfterThrowing

@AfterThrowing是一種通知型別，可以確保在方法丟擲異常時執行一個通知。以下是@AfterThrowing通知的語法：

語法

@AfterThrowing(pointcut="execution(* com.yiibai.Student.*(..))", throwing= "error")
public void afterThrowingAdvice(JoinPoint jp, Throwable error){
   System.out.println("Method Signature: "  + jp.getSignature());  
   System.out.println("Exception: "+error);  
}

在上面的語法範例中 -

@AfterReturning - 如果方法返回成功，則將函式標記為在切入點覆蓋的方法之前執行的通知。
@Pointcut - 將函式標記為切入點
@After - 將函式標記為在切入點覆蓋的方法之後執行的通知。
execution( expression ) - 涵蓋應用通知的方法的表示式。
throwing - 返回的異常名稱。

要了解上面提到的@AfterThrowing通知相關的概念，我們寫一個Spring AOP基於註解的應用例子，它將使用基於註解組態實現通知。開啟並使用Eclipse IDE，並按照以下步驟建立一個Spring應用程式：

更新在Spring AOP應用範例中建立過的Student專案。
更新bean組態並執行應用程式，如下所述。

整個專案的目錄結構如下所示 -

下面是Logging.java檔案的內容。這實際上是一個Aspect模組的樣本，它定義了在各個點被呼叫的方法。

package com.yiibai;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.JoinPoint;  
import org.aspectj.lang.annotation.AfterThrowing;  

@Aspect
public class Logging {

   /** 
    * This is the method which I would like to execute
    * after a selected method execution throws exception.
    */
   @AfterThrowing(pointcut="execution(* com.yiibai.Student.*(..))", throwing= "error")
   public void afterThrowingAdvice(JoinPoint jp, Throwable error){
      System.out.println("[afterThrowingAdvice] Method Signature: "  + jp.getSignature());  
      System.out.println("[afterThrowingAdvice] Exception: "+error);  
   }
}

以下是Student.java檔案的內容：

package com.yiibai;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = 
             new ClassPathXmlApplicationContext("Beans.xml");

      Student student = (Student) context.getBean("student");

      student.printThrowException();     
   }
}

以下是MainApp.java檔案的內容：

package com.yiibai;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = 
             new ClassPathXmlApplicationContext("Beans.xml");

      Student student = (Student) context.getBean("student");

      student.printThrowException();     
   }
}

以下是組態檔案Beans.xml檔案的內容：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/aop 
    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">

   <aop:aspectj-autoproxy/>

   <!-- Definition for student bean -->
   <bean id="student" class="com.yiibai.Student">
      <property name="name"  value="minsu" />
      <property name="age"  value="24"/>      
   </bean>

   <!-- Definition for logging aspect -->
   <bean id="logging" class="com.yiibai.Logging"/> 

</beans>

執行專案

完成建立原始碼和組態檔案後，執行應用程式。右鍵單擊應用程式中的MainApp.java，並使用執行方式作為Java應用程式命令。如果您的應用程式一切正常，這將列印以下訊息：

Exception raised
[afterThrowingAdvice] Method Signature: void com.yiibai.Student.printThrowException()
[afterThrowingAdvice] Exception: java.lang.IllegalArgumentException
Exception in thread "main" java.lang.IllegalArgumentException
    at com.yiibai.Student.printThrowException(Student.java:25)
    at com.yiibai.Student$$FastClassBySpringCGLIB$$e9280b4b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
    at com.yiibai.Student$$EnhancerBySpringCGLIB$$bb5ffc0.printThrowException(<generated>)
    at com.yiibai.MainApp.main(MainApp.java:16)