Spring AOP 基于XML的After Throwing Advice

After-throwing 是一种通知类型，它确保在方法执行后运行通知，只有当方法通过抛出异常退出时才会运行。以下是投掷后建议的语法。

句法

<aop:config>
   <aop:aspect id = "log" ref = "logging">
      <aop:PointCut id = "PointCut-id" expression = "execution( expression )"/>    
      <aop:after-throwing PointCut-ref = "PointCut-id" throwing = "ex"
         method = "methodName"/>
   </aop:aspect>
</aop:config>

这里

PointCut-id - PointCut的id 。
ex - 被抛出的异常。
methodName - 被调用函数抛出异常并退出时要调用的函数的方法名称。

为了理解上述与After Throwing Advice相关的概念，让我们编写一个实现After Throwing Advice的示例。要编写我们的示例并提供一些建议，让我们使用一个可用的Eclipse IDE并使用以下步骤创建一个Spring应用程序

步	描述
1	更新项目学生根据Spring AOP - Application章节创建。
2	更新bean配置并运行应用程序，如下所述。

以下是 Logging.java 文件的内容。这实际上是方面模块的一个示例，它定义了在各个点调用的方法。

package com.codingdict;

public class Logging {
   /**
    * This is the method which I would like to execute
    * if there is an exception raised.
    */
   public void afterThrowingAdvice(IllegalArgumentException ex) {
      System.out.println("There has been an exception: " + ex.toString());   
   }
}

以下是 Student.java 文件的内容。

package com.codingdict;

public class Student {
   private Integer age;
   private String name;

   public void setAge(Integer age) {
      this.age = age;
   }
   public Integer getAge() {
      System.out.println("Age : " + age );
      return age;
   }

   public void setName(String name) {
      this.name = name;
   }

   public String getName() {
      System.out.println("Name : " + name );
      return name;
   }

   public void printThrowException(){
      System.out.println("Exception raised");
      throw new IllegalArgumentException();
   }
}

以下是 MainApp.java 文件的内容。

package com.codingdict;

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();     
   }
}

以下是配置文件 Beans.xml 。

<?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:config>
      <aop:aspect id = "log" ref = "logging">
         <aop:PointCut id = "selectAll"
         expression = "execution(* com.codingdict.*.*(..))"/>
         <aop:after-throwing PointCut-ref = "selectAll"
            throwing = "ex" method = "afterThrowingAdvice"/>         
      </aop:aspect>
   </aop:config>

   <!-- Definition for student bean -->
   <bean id = "student" class = "com.codingdict.Student">
      <property name = "name"  value = "Zara" />
      <property name = "age"  value = "11"/>      
   </bean>

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

</beans>

运行项目

完成源和配置文件的创建后，运行您的应用程序。右键单击应用程序中的MainApp.java，并使用 run as Java Application 命令。如果您的应用程序一切正常，它将打印以下消息。

Exception raised
There has been an exception: java.lang.IllegalArgumentException
Exception in thread "main" java.lang.IllegalArgumentException
   at com.codingdict.Student.printThrowException(Student.java:25)

   at com.codingdict.Student$$FastClassBySpringCGLIB$$7dc55815.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.codingdict.Student$$EnhancerBySpringCGLIB$$8514cd8.printThrowException(<generated>)

   at com.codingdict.MainApp.main(MainApp.java:15)