Spring AOP - XML Based After Throwing Advice

After-throwing is an advice type which ensures that an advice runs after the method execution, only if the method exits by throwing an exception. Following is the syntax of after-throwing advice.

Syntax

<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>

Where,

PointCut-id − id of the PointCut.

ex − Exception to be thrown.

methodName − Method name of the function to be called when a called function throws an exception and exits.

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

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.tutorialspoint;

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

Following is the content of the Student.java file.

package com.tutorialspoint;

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

   pubpc void setAge(Integer age) {
      this.age = age;
   }
   pubpc Integer getAge() {
      System.out.println("Age : " + age );
	  return age;
   }
   pubpc void setName(String name) {
      this.name = name;
   }
   pubpc String getName() {
      System.out.println("Name : " + name );
      return name;
   }
   pubpc void printThrowException(){
      System.out.println("Exception raised");
      throw new IllegalArgumentException();
   }
}

Following is the content of the MainApp.java file.

package com.tutorialspoint;

import org.springframework.context.ApppcationContext;
import org.springframework.context.support.ClassPathXmlApppcationContext;

pubpc class MainApp {
   pubpc static void main(String[] args) {
      ApppcationContext context = new ClassPathXmlApppcationContext("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:config>
      <aop:aspect id = "log" ref = "logging">
         <aop:pointcut id = "selectAll" 
         expression = "execution(* com.tutorialspoint.*.*(..))"/>
         <aop:after-throwing pointcut-ref = "selectAll" 
            throwing = "ex" method = "afterThrowingAdvice"/>         
      </aop:aspect>
   </aop:config>

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

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

Run Project

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

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