View 분리

public class MemberSaveControllerV1 implements ControllerV1 {
    private MemberRepository memberRepository = MemberRepository.getInstance();

    @Override
    public void process(HttpServletRequest request, HttpServletResponse response) {

      ...

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

모든 컨트롤러에서 뷰로 이동하는 부분에 중복이 있다.

구조

별도로 뷰를 처리하는 객체를 만들어보자.

MyView.java

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.java

public interface ControllerV2 {
    MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

따로 뷰 처리 하는 클래스를 만들어서 최상위 컨트롤러에서 이 타입을 반환하게 한다.

MemberFormControllerV2.java

public class MemberFormControllerV2 implements ControllerV2 {
    @Override
    public MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        return new MyView("/WEB-INF/views/new-form.jsp");
    }
}

MemberSaveControllerV2.java

public class MemberSaveControllerV2 implements ControllerV2 {

    private 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);

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

MemberListControllerV2.java

public class MemberListControllerV2 implements ControllerV2 {

    private MemberRepository memberRepository = MemberRepository.getInstance();

    @Override
    public MyView process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List<Member> members = memberRepository.findAll();
        request.setAttribute("members", members);
        return new MyView("/WEB-INF/views/members.jsp");
    }
}

각 컨트롤러는 MyView 타입을 반환한다.

FrontControllerServletV2.java

@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);
    }
}

프론트 컨트롤러에서 생성된 뷰로 렌더한다.