<Spring> 8. AOP

1. AOP

• OOP ( Object Oriented Programming ), AOP( Aspect[관심] Oriented Programming)

• java는 OOP로 핵심로직(종단관심), 공통로직(횡단관심)으로 구성되어있다.

• AOP는 관점 지향 프로그래밍으로  OOP에서 공통로직( 횡단관심 )을 분리하여 구성--> 모듈성 증가

• Maven : spring 라이브러리를 자동으로 처리, aspectj weaver 필요( Dependency 추가 ) & namespace

    https://mvnrepository.com/artifact/org.aspectj/aspectjweaver

• aop:pointcut 공통로직을 연결할 대상 찾기, execution =() --> id

• 접근지시자(생략하면 모든) return-type package.class.method(parameters) , *모든 . 현재 .. 하위

• parameters (..) -> 어떤것이든 상관없다.(0개이상, 없으면 매개변수 없는 것)

• ※ 일반 객체 생성시 적용안됨

<bean id="be2" class="aop.Aop" />
 
<aop:config>
 <aop:pointcut expression="execution(public * aop.*.*(..))" id="pc"/>
 <aop:aspect ref="be">
 <aop:before method="before" pointcut-ref="pc"/>
 </aop:aspect>
</aop:config>
======================================================
Aop aop=aContext.getBean("be2",Aop.class);
Aop aop2=new Aop();
aop.progress();
aop2.progress(); //적용안됨
=====================================================

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

<aop:config>  //aop 구성  <aop:pointcut expression="execution(public * aop.*.*(..))" id="pc"/> //execution(접근지시자 리턴값 패키지명+메소드명(파리미터s)  )  <aop:aspect ref="be">  <aop:before method="aop메소드" pointcut-ref="pc"/> <aop:after method="" pointcut-ref=""/> //실행하기 전후  <aop:around method="" pointcut-ref=""/> //before+after  <aop:after-returning method="" pointcut-ref="" /> // return 값을 받거나 잘 실행될 경우  <aop:after-throwing method="" pointcut-ref=""/> // 예외 전달  </aop:aspect> </aop:config>   Colored by Color Scripter

cs

• <예제>

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

public void around(ProceedingJoinPoint joinPoint) {         try {             System.out.println("AROUND처음실행");             joinPoint.proceed(); // proceed 기준으로 위에 before,                                                        // 아래는 after             System.out.println("AROUND나중실행");         } catch (Throwable e) {            // TODO Auto-generated catch block             e.printStackTrace();         }             }   public void before() {         System.out.println("BEFORE실행");     } public void affter() {         System.out.println("AFTER실행");     } ==============Main================= test.display_ba("Hello");//매개변수 출력 System.out.println(); test.display_ar("Hello","world"); Colored by Color Scripter

cs

<bean id="test" class="aop.Test"></bean>
 
<aop:config>
 <aop:pointcut expression="execution(public * aop.Test.display_ba(..))" id="pc"/>
 <aop:aspect ref="be">
 <aop:before method="before" pointcut-ref="pc"/>
 <aop:after method="affter" pointcut-ref="pc"/>
 <aop:around method="around" pointcut="execution(public * aop.Test.display_ar(..))"/>
 </aop:aspect>
</aop:config>

실행

2. Annotation aop

• Annotation만으로도 aop를 설정 가능하다. , XML-> Namespaces -> context 체크
  

===============XML===================
<context:component-scan base-package="test"/>
// Component 들을 찾아서 매핑
<aop:aspectj-autoproxy/>
//자동으로 Annotaion aop를 매핑
================Aop.java================
@Component
@Aspect
//Aop 어노테이션 자동으로 설정 
public class Aop {    
@Pointcut("execution(public void test.*.*(..))")
  public void point() {}//중복되는 것 하나로 설정    
@Before("point()")
  public void before() {
        System.out.println("BEFORE실행");}
@After("point()")
  public void after() {
        System.out.println("AFTER실행");}
//리턴값을 받아서 처리하기 때문에 returnning설정 필수    
@AfterReturning(pointcut="execution(public int test.*.*())",
returning="returnValue" )
    public void afterReturn(int returnValue) {
        System.out.println("30마리 가격 : "+ returnValue*30);}
}
==================Main.java==========================
ApplicationContext aContext=
    new ClassPathXmlApplicationContext("aopt.xml");
      Dog beagle=aContext.getBean("dog",Dog.class);
     Dog mala=aContext.getBean("dog2",Dog.class);
          
    beagle.bark();
        System.out.println();
    mala.bark();
        System.out.println();        
    beagle.avg_price();
        System.out.println();
    mala.avg_price();
=====================================================    

실행