Spring AOP - Annotation Based After Throwing Advice

@AfterThrowing is an advice type which ensures that an advice runs if the method throws an exception. Following is the syntax of @AfterThrowing advice.

Syntax

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

Where,

• @AfterThrowing − Mark a function as an advice to be executed before method(s) covered by PointCut, if the method throws an exception.

• PointCut − Provides an expression to select a function.

• execution( expression ) − Expression covering methods on which advice is to be applied.

• throwing − Name of the exception to be returned.

To understand the above-mentioned concepts related to @AfterThrowing Advice, let us write an example which will implement @AfterThrowing Advice. To write our example with few advices, let us have a working Eclipse IDE in place and use the following steps to create a Spring application.

Following is the content of Logging.java file. This is actually a sample of aspect module, which defines the methods to be called at various points.

package com.howcodex;

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

Following is the content of the Student.java file.

package com.howcodex;

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();
   }
}

Following is the content of the MainApp.java file.

package com.howcodex;

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();     
   }
}

Following is the configuration file 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:aspectj-autoproxy/>

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

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

Run Project

Once you are done creating the source and configuration files, run your application. Rightclick on MainApp.java in your application and use run as Java Application command. If everything is fine with your application, it will print the following message.

Exception raised
Method Signature: void com.howcodex.Student.printThrowException()
Exception: java.lang.IllegalArgumentException
Exception in thread "main" java.lang.IllegalArgumentException
   
   at com.howcodex.Student.printThrowException(Student.java:25)
   
   at com.howcodex.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.howcodex.Student$$EnhancerBySpringCGLIB$$99b0a988.printThrowException(<generated>)
   
   at com.howcodex.MainApp.main(MainApp.java:13)