springAOP : @Before

The AspectJ Before Advice is applied before the actual business logic method. You can perform any operation here such as conversion, authentication etc.

Create a class that contains actual business logic.

Employee.java

==========

package com.mohan; 

public  class Employee{ 

    public void msg(){System.out.println("msg method invoked");} 

    public int m(){System.out.println("m method invoked");return 2;} 

    public int k(){System.out.println("k method invoked");return 3;} 

} 

Now, create the aspect class that contains before advice.

TrackEmployee.java

=============

package com.mohan; 

 

import org.aspectj.lang.JoinPoint; 

import org.aspectj.lang.annotation.Aspect; 

import org.aspectj.lang.annotation.Before; 

import org.aspectj.lang.annotation.Pointcut; 

 

@Aspect 

public class TrackEmployee{ 

    @Pointcut("execution(* Employee.k*(..))") 

    public void k(){}//pointcut name 

     

    @Before("k()")//applying pointcut on before advice 

    public void myadvice(JoinPoint jp)//it is advice (before advice) 

    { 

        System.out.println("additional concern");       

    } 

} 

Now create the Beans.xml file that defines beans.

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.xsd  

       http://www.springframework.org/schema/aop  

       http://www.springframework.org/schema/aop/spring-aop.xsd"> 

 

 

    <bean id="empBean" class="com.mohan.Employee">   </bean> 

    <bean id="trackEmp" class="com.mohan.TrackEmployee"></bean> 

     

    <bean class="org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator"></bean> 

         

</beans>  

Now, let's call the actual method.

Test.java

======

package com.mohan; 

 

import org.springframework.context.ApplicationContext; 

import org.springframework.context.support.ClassPathXmlApplicationContext; 

public class Test{ 

    public static void main(String[] args){ 

        ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); 

        Employee e = (Employee) context.getBean("empBean"); 

        System.out.println("calling msg..."); 

        e.msg(); 

        System.out.println("calling m..."); 

        e.m(); 

        System.out.println("calling k..."); 

        e.k(); 

    } 

}   

Expected Output

calling msg... 

additional concern 

msg() method invoked 

calling m... 

additional concern 

m() method invoked 

calling k... 

additional concern 

k() method invoked