MVC 프레임워크 6

package hello.servlet.web.frontcontroller.v5;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import hello.servlet.web.frontcontroller.ModelView;
import hello.servlet.web.frontcontroller.MyView;
import hello.servlet.web.frontcontroller.v3.controller.MemberFormControllerV3;
import hello.servlet.web.frontcontroller.v3.controller.MemberListControllerV3;
import hello.servlet.web.frontcontroller.v3.controller.MemberSaveControllerV3;
import hello.servlet.web.frontcontroller.v4.controller.MemberFormControllerV4;
import hello.servlet.web.frontcontroller.v4.controller.MemberListControllerV4;
import hello.servlet.web.frontcontroller.v4.controller.MemberSaveControllerV4;
import hello.servlet.web.frontcontroller.v5.adapter.ControllerV3HandlerAdapter;
import hello.servlet.web.frontcontroller.v5.adapter.ControllerV4HandlerAdapter;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;


@WebServlet(name = "frontControllerServletV5", urlPatterns = "/front-controller/v5/*")
public class FrontControllerServletV5 extends HttpServlet {

	//컨트롤러 다 지원하기 위해 Object를 사용한다.
	private final Map<String, Object> handlerMappingMap = new HashMap<>();
	private final List<MyHandlerAdapter> handlerAdapters = new ArrayList<>(); 
	
	public FrontControllerServletV5() {
		initHandlerAdapters();  	//핸들러 매핑 초기화
		initHandlerMappingMap(); 	//어댑터 초기화
	}
	
	private void initHandlerAdapters() {
		//V3
		handlerMappingMap.put("/front-controller/v5/v3/members/new-form", new MemberFormControllerV3());
		handlerMappingMap.put("/front-controller/v5/v3/members/save", new MemberSaveControllerV3());
		handlerMappingMap.put("/front-controller/v5/v3/members", new MemberListControllerV3());
		//V4 추가 됨
		handlerMappingMap.put("/front-controller/v5/v4/members/new-form", new MemberFormControllerV4());
		handlerMappingMap.put("/front-controller/v5/v4/members/save", new MemberSaveControllerV4());
		handlerMappingMap.put("/front-controller/v5/v4/members", new MemberListControllerV4());
	}
	
	private void initHandlerMappingMap() {
		//V3
		handlerAdapters.add(new ControllerV3HandlerAdapter());
		//V4 추가 됨
		handlerAdapters.add(new ControllerV4HandlerAdapter());
	}
	
	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		//1.요청에 맞는 핸들러 매핑 정보 조회
		Object handler = getHandler(request);
		
		if (handler == null) {
			response.setStatus(HttpServletResponse.SC_NOT_FOUND);
			return;
		}
		
		//2.위에서 찾은 핸들러를 처리할 수 있는 핸들러 어댑터 조회
		MyHandlerAdapter adapter = getHandlerAdapter(handler);
		
		//3.핸들러 어댑터에서 핸들러(컨트롤러) 호출 후  
		//4.모델뷰 반환
		ModelView mv = adapter.handle(request, response, handler);

		//5.뷰리졸버 호출 
		//6.마이뷰 반환
		String viewName = mv.getViewName(); 
		MyView view =  viewResolver(viewName);
		
		//7.렌더(모델) 호출 
		view.render(mv.getModel(), request, response);
	}
	
	//핸들러 매핑 정보인 handlerMappingMap 에서 URL에 매핑된 핸들러(컨트롤러) 객체를 찾아서 반환한
	private Object getHandler(HttpServletRequest request) {
		String requestURI = request.getRequestURI();
		return handlerMappingMap.get(requestURI);
	}
	
	//handler를 처리할 수 있는 어댑터를 adapter.supports(handler) 를 통해서 찾는다
	private MyHandlerAdapter getHandlerAdapter(Object handler) {
		for (MyHandlerAdapter adapter : handlerAdapters) {
			if(adapter.supports(handler)) {
				return adapter;
			}
		}
		
		throw new IllegalArgumentException("handler adapter를 찾을 수 없습니다. handler=" + handler);
	}
	
	public MyView viewResolver(String viewName) {
		return new MyView("/WEB-INF/views/" +viewName+ ".jsp");
	}
	
}

package hello.servlet.web.frontcontroller.v5.adapter;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import hello.servlet.web.frontcontroller.ModelView;
import hello.servlet.web.frontcontroller.v4.ControllerV4;
import hello.servlet.web.frontcontroller.v5.MyHandlerAdapter;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

public class ControllerV4HandlerAdapter implements MyHandlerAdapter{

	@Override
	public boolean supports(Object handler) {
		//handler가 ControllerV4를 상속받은 type이라면 true 리턴
		return (handler instanceof ControllerV4);
	}
	
	@Override
	public ModelView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws ServletException, IOException {
		
		ControllerV4 controller = (ControllerV4)handler;
		
		Map<String, String> paramMap = createParamMap(request);
		HashMap<String, Object> model = new HashMap<>();
		
		String viewName = controller.process(paramMap, model);
		
		ModelView mv = new ModelView(viewName);
		mv.setModel(model);
		
		return mv;
	}
	
	public Map<String, String> createParamMap(HttpServletRequest request){
		Map<String, String> paramMap = new HashMap<>(); 
		request.getParameterNames().asIterator().forEachRemaining(paramName->paramMap.put(paramName, request.getParameter(paramName)));
		return paramMap;
	}
}