Naming Conventions and Custom Advice Annotations

 I share some thoughts on naming conventions, and how it helps in the case of writing aspects in Spring. We will also understand how to write our own custom annotations to apply advice to methods.

package com.venkat.Spring.Aop;

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

import com.venkat.Spring.Aop.service.ShapeService;

public class AopTest {

    public static void main(String args[])
    {
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        ShapeService service=context.getBean("shapeService",ShapeService.class);
        service.getCircle();
    }
}
***************************************************************************

package com.venkat.Spring.Aop.Aspect;

public @interface Loggable {

}
**************************************************************************

package com.venkat.Spring.Aop.Aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;

import com.venkat.Spring.Aop.model.Circle;

@Aspect
public class LoggingAspect {
   
    public void loggingAdvice(JoinPoint joinpoint)
    {
        System.out.println("Run Advice..... get method Executed");
        System.out.println(joinpoint.toString());
        Circle c=(Circle)joinpoint.getTarget();
        System.out.println(c.getName());
    }
   
    @AfterReturning(pointcut="args(name)",returning="returnString")
    public void allStringMethodArguments(String name, String returnString){
    System.out.println("A setter method has been executed............"+name);
    }
   
    @AfterThrowing(pointcut="args(name)",throwing="ex")
    public void exceptionAdvice(String name, Exception ex){
    System.out.println("Exception is thrown ............"+ex);
    }
   
    @After("args(String)")
    public void afterAdvice(){
    System.out.println("After Advice is executed...........");
    }

    @Pointcut("execution(*  get*())")
    public void allGetters(){}
   
   
    @Around("@annotation(com.venkat.Spring.Aop.Aspect.Loggable)")
    public Object myAroundAdvice(ProceedingJoinPoint proceedingJoinPoint)
    {
        Object returnValue=null;
            try {
                System.out.println("Before method Executed");
                returnValue=proceedingJoinPoint.proceed();
                System.out.println("After Method Executed....");
            } catch (Throwable e) {
                System.out.println("Around Advice throws exception");
        }
        System.out.println("After Finally executed........");
              
        return returnValue;
    }
   
   
}
*******************************************************************************

package com.venkat.Spring.Aop.model;

public class Circle {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
        System.out.println("Setter method is called.....");
        throw(new RuntimeException());
    }
   
    public String setNameAndReturning(String name) {
        this.name = name;
        System.out.println("Setter Method and return the value method executed....");
        return name;
    }
}
********************************************************************************

package com.venkat.Spring.Aop.model;

public class Triangle {

    private String name;

    public String getName() {
        return name;
    }

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

package com.venkat.Spring.Aop.service;

import com.venkat.Spring.Aop.Aspect.Loggable;
import com.venkat.Spring.Aop.model.Circle;
import com.venkat.Spring.Aop.model.Triangle;

public class ShapeService {

    private Triangle triangle;
    private Circle circle;
    public Triangle getTriangle() {
        return triangle;
    }
    public void setTriangle(Triangle triangle) {
        this.triangle = triangle;
    }
    @Loggable
    public Circle getCircle() {
        return circle;
    }
    public void setCircle(Circle circle) {
        this.circle = circle;
    }
}
******************************************************************************

<?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"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
                http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
                http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<aop:aspectj-autoproxy/>
    <bean name="triangle" class="com.venkat.Spring.Aop.model.Triangle">
    <property name="name" value="triangle name"/>
    </bean>
    <bean name="circle" class="com.venkat.Spring.Aop.model.Circle">
<!--     <property name="name" value="circle name"/>  -->
    </bean>
    <bean name="shapeService" class="com.venkat.Spring.Aop.service.ShapeService">
    <property name="triangle" ref="triangle"/>
    <property name="circle" ref="circle"/>
    </bean>
    <bean  name="loggingAdvice" class="com.venkat.Spring.Aop.Aspect.LoggingAspect"/>
</beans>