4. AOP 기초 완성.md

AOP 기초 완성

• 이번에는 After 어드바이스까지 추가해 살펴보도록 하겠습니다.
• After 어드바이스는 해당 JoinPoint 메소드를 실행한 후에 실행됩니다.

POJO & XML 기반 코드

package aop001;

import org.aspectj.lang.JoinPoint;

@Aspect
public class MyAspect {
    public void before(JoinPoint joinPoint) {
        System.out.println("얼굴 인식 확인: 문 개방");
    }
    
    public void lockDoor(JoinPoint joinPoint) {
        System.out.println("문 잠금");
    }
}

<?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/aop
        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
        
    <aop:aspectj-autoproxy />
    
    <bean id="myAspect" class="aop001.MyAspect"></bean>
    <bean id="boy" class="aop001.Boy"></bean>
    <bean id="girl" class="aop001.Girl"></bean>
    
    <aop:config>
        <aop:aspect ref="myAspect">
            <aop:before method="before" pointcut="execution(* runSomething())" />
            <aop:after method="lockDoor" pointcut="execution(* runSomething())" />
        </aop:aspect>
    </aop:config>
</beans>

---

@ 어노테이션 기반 코드

package aop001;

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

@Aspect
public class MyAspect {
    @Before("execution(* runSomething())")
    public void before(JoinPoint joinPoint) {
        System.out.println("얼굴 인식 확인: 문 개방");
    }
    
    @After("execution(* runSomething())")
    public void lockDoor(JoinPoint joinPoint) {
        System.out.println("문 잠금");
    }
}

<?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/aop
        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
        
    <aop:aspectj-autoproxy />
    
    <bean id="myAspect" class="aop001.MyAspect"></bean>
    <bean id="boy" class="aop001.Boy"></bean>
    <bean id="girl" class="aop001.Girl"></bean>
</beans>

• 위 XML 기반과 어노테이션 기반 코드에서 눈에 거슬리는 부분이 있는데, 바로 중복되는 내용이 있다는 것입니다.

리팩터링된 POJO 및 XML 기반 스프링 설정 파일

<?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/aop
        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
        
    <aop:aspectj-autoproxy />
    
    <bean id="myAspect" class="aop001.MyAspect"></bean>
    <bean id="boy" class="aop001.Boy"></bean>
    <bean id="girl" class="aop001.Girl"></bean>
    
    <aop:config>
        <aop:pointcut expression="execution(* runSomething())" id="iampc" />
        <aop:aspect ref="myAspect">
            <aop:before method="before" pointcut-ref="iampc" />
            <aop:after method="lockDoor" pointcut-ref="iampc" />
        </aop:aspect>
    </aop:config>
</beans>

리팩터링된 어노테이션 기반 MyAspect.java

package aop001;

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

@Aspect
public class MyAspect {
    @Pointcut("execution(* runSomething())")
    private void iampc() {
        // 여긴 무엇을 작성해도 의미가 없습니다.
    }

    @Before("iampc()")
    public void before(JoinPoint joinPoint) {
        System.out.println("얼굴 인식 확인: 문 개방");
    }
    
    @After("iampc()")
    public void lockDoor(JoinPoint joinPoint) {
        System.out.println("문 잠금");
    }
}