Spring AOP

Why spring aop advice is not triggering(invoking) for setter methods  invoked  by spring container ?

Problem :   The actual problem is explained by using below example.

 Bean class:

package org.example;

public class Triangle {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        System.out.println("In setter");
        this.name = name;
    }

}

Bean configuration  in spring.xml

<aop:aspectj-autoproxy />       

<bean id="triangle" class="org.example.Triangle" >
<property name="name" value="Right Angle Triangle"/>

</bean>
<bean id="firstaspect" class="org.example.aspects.SampleAspect"/>

Aspect class:

package org.example.aspects;

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

@Aspect
public class SampleAspect {
    @Before("execution(public void setName(..))")
    public void testAdvice(JoinPoint joinPoint){
            System.out.println("Aspect Signature "+joinPoint.getSignature());
              
    }

}

spring client program:

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

public class AOPClient {

    /**
     * @param args
     */
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring.xml");
        Triangle triangle=ctx.getBean("triangle",Triangle.class);
             System.out.println("Triangle name: "+triangle.getName());

    }

}

output :
In setter

Triangle name: Right Angle Triangle

As per the spring aop concept the adviser  testAdvice must be called  before executing the setter method setName(String name) but  the adviser is not triggering.
because AOP Proxy works only after the bean complete initialization i.e after setting all the properties through DependecnyInjection.
after succesful initialization of bean if you invoke the setter method again from your client program then it'll trigger the advisor.

public static void main(String[] args) {
         ApplicationContext ctx = new ClassPathXmlApplicationContext("spring.xml");
         Triangle triangle=ctx.getBean("triangle",Triangle.class);
        triangle.setName("Equilateral Triangle");

        System.out.println("Triangle name: "+triangle.getName());

   
    }

output:

In setter //This output line is called through spring container

Aspect Signature String org.example.Triangle.getName()

In setter //This output line is called through AOPClient Class

Triangle name:Equilateral Triangle