[김영한 스프링] 14. MVC 프레임워크 만들기 - View 분리

View 분리 - v2

 

V2 구조

 

 

MyView

main/java/hello.servlet/web/frontcontroller/MyView 생성

 

 

package hello.servlet.web.frontcontroller;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyView {

    private String viewPath;

    public MyView(String viewPath) {
        this.viewPath = viewPath;
    }

    public void render(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        RequestDispatcher dispatcher = request.getRequestDispatcher(viewPath);
        dispatcher.forward(request, response);
    }
}

 

 

ControllerV2

package hello.servlet.web.frontcontroller.v2;

import hello.servlet.web.frontcontroller.MyView;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public interface ControllerV2 {

    MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

main/java/hello.servlet/web/frontcontroller/v2/ControllerV2 생성

 

 

MemberFormControllerV2 - 회원 등록 폼

main/java/hello.servlet/web/frontcontroller/v2/controller/MemberFormControllerV2 생성

 

 

package hello.servlet.web.frontcontroller.v2.controller;

import hello.servlet.web.frontcontroller.MyView;
import hello.servlet.web.frontcontroller.v2.ControllerV2;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MemberFormControllerV2 implements ControllerV2 {

    @Override
    public MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

//        String viewPath = "/WEB-INF/views/new-form.jsp";
//        RequestDispatcher dispatcher = request.getRequestDispatcher(viewPath);
//        dispatcher.forward(request, response);

        return new MyView("/WEB-INF/views/new-form.jsp");
    }
}

이제 각 컨트롤러는 복잡한 dispatcher.forward()를 직접 생성해서 호출하지 않아도 된다. 단순히 MyView 객체를 생성하고 거기에 뷰 이름만 넣고 반환하면 된다.

 

 

MemberSaveControllerV2 - 회원 저장

main/java/hello.servlet/web/frontcontroller/v2/controller/MemberSaveControllerV2 생성

 

 

package hello.servlet.web.frontcontroller.v2.controller;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;
import hello.servlet.web.frontcontroller.MyView;
import hello.servlet.web.frontcontroller.v2.ControllerV2;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MemberSaveControllerV2 implements ControllerV2 {

    MemberRepository memberRepository = MemberRepository.getInstance();

    @Override
    public MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String username = request.getParameter("username");
        int age = Integer.parseInt(request.getParameter("age"));

        Member member = new Member(username, age);
        memberRepository.save(member);

        // Model에 데이터를 보관한다.
        request.setAttribute("member", member);

//        String viewPath = "/WEB-INF/views/save-result.jsp";
//        RequestDispatcher dispatcher = request.getRequestDispatcher(viewPath);
//        dispatcher.forward(request, response);

        return new MyView("/WEB-INF/views/save-result.jsp");
    }
}

 

 

MemberListControllerV2 - 회원 목록

main/java/hello.servlet/web/frontcontroller/v2/controller/MemberListControllerV2 생성

 

 

package hello.servlet.web.frontcontroller.v2.controller;

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;
import hello.servlet.web.frontcontroller.MyView;
import hello.servlet.web.frontcontroller.v2.ControllerV2;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

public class MemberListControllerV2 implements ControllerV2 {

    MemberRepository memberRepository = MemberRepository.getInstance();

    @Override
    public MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        List<Member> members = memberRepository.findAll();

        request.setAttribute("members", members);

//        String viewPath = "/WEB-INF/views/members.jsp";
//        RequestDispatcher dispatcher = request.getRequestDispatcher(viewPath);
//        dispatcher.forward(request, response);

        return new MyView("/WEB-INF/views/members.jsp");
    }
}

 

 

프론트 컨트롤러 V2

main/java/hello.servlet/web/frontcontroller/v2/FrontControllerServletV2 생성

 

 

package hello.servlet.web.frontcontroller.v2;

import hello.servlet.web.frontcontroller.MyView;
import hello.servlet.web.frontcontroller.v2.controller.MemberFormControllerV2;
import hello.servlet.web.frontcontroller.v2.controller.MemberListControllerV2;
import hello.servlet.web.frontcontroller.v2.controller.MemberSaveControllerV2;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

@WebServlet(name = "frontControllerServletV2", urlPatterns = "/front-controller/v2/*")
public class FrontControllerServletV2 extends HttpServlet {

    private Map<String, ControllerV2> controllerMap = new HashMap<>();

    public FrontControllerServletV2() {
        controllerMap.put("/front-controller/v2/members/new-form", new MemberFormControllerV2());
        controllerMap.put("/front-controller/v2/members/save", new MemberSaveControllerV2());
        controllerMap.put("/front-controller/v2/members", new MemberListControllerV2());
    }

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("FrontControllerServletV2.service");

        String requestURI = request.getRequestURI();

        ControllerV2 controller = controllerMap.get(requestURI);

        if (controller == null) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        MyView view = controller.process(request, response);
        view.render(request, response);
    }
}

ControllerV2의 반환 타입이 MyView 이므로 프론트 컨트롤러는 컨트롤러의 호출 결과로 MyView를 반환받는다. 그리고 view.render()를 호출하면 forward 로직을 수행해서 JSP가 실행된다.

 

 

실행

 

 

출처 : https://www.inflearn.com/course/%EC%8A%A4%ED%94%84%EB%A7%81-mvc-1

스프링 MVC 1편 - 백엔드 웹 개발 핵심 기술 - 인프런 | 강의