[Spring] AOP란?

AOP 프로젝트 세팅

gradle을 통해 다운

dependencies에 
    implementation 'org.springframework.boot:spring-boot-starter-aop'     // 추가

 

controller RestApiController 생성

package com.example.aop.controller;

import com.example.aop.dto.User;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api")
public class RestApiController {
    @GetMapping("/get/{id}")
    void get(@PathVariable Long id, @RequestParam String name){
        System.out.println("id = " + id + ", name = " + name);
    }
    @PostMapping("/post")
    void post(@RequestBody User user){
        System.out.println("post method " + user);


    }
}

DTO User.class 생성

package com.example.aop.dto;

public class User {
    private String id;
    private String pw;
    private String email;


    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getPw() {
        return pw;
    }

    public void setPw(String pw) {
        this.pw = pw;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "User{" +
                "id='" + id + '\'' +
                ", pw='" + pw + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}

AOP 를 만들어 설정

package com.example.aop.aop;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

@Aspect //흩어진 관심사를 모듈화 한 것. 주로 부가기능을 모듈화함.
@Component
public class ParameterAop {

    @Pointcut("execution(* com.example.aop.controller..*.*(..))") //내가 어느부분에 적용시킬것인지 => 특정  controller하위
    private void pointcut(){

    }

    @Before("pointcut()") //메서드 실행전(언제 실행할것이냐)  => pointcut실행되는 지점
    public void before(JoinPoint joinPoint){  //joinPoint 라는 객체 를 가지고 있음
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        Method method = methodSignature.getMethod();
        System.out.println(method.getName()); // 어떤메서드를 실행했는지 확인

        Object[] arg = joinPoint.getArgs();

        for (Object obj : arg){
            System.out.println("type = " + obj.getClass().getSimpleName());
            System.out.println("value = " + obj);
        }
    }

    @AfterReturning(value = "pointcut()", returning = "returnodj")   //메서드 실행이 되어을때 반환값이 알고싶을때  => pointcut실행되는 지점
    public void afterReture(JoinPoint joinPoint, Object returnodj){ // object값을 가짐
        System.out.println("joinPoint = " + joinPoint + ", returnodj = " + returnodj);

    }

}

post

get