spring mvc : mvc 프레임워크 만들기 - 실용적인 컨트롤러

spring-mvc/servlet/src/main/java/com/example/servlet/web/frontcontroller/v4/ControllerV4.java

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+package com.example.servlet.web.frontcontroller.v4;
+
+import java.util.Map;
+
+public interface ControllerV4 {
+
+    String process(Map<String, String> paramMap, Map<String, Object> model);
+}

spring-mvc/servlet/src/main/java/com/example/servlet/web/frontcontroller/v4/FrontControllerServletV4.java

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+package com.example.servlet.web.frontcontroller.v4;
+
+import com.example.servlet.web.frontcontroller.MyView;
+import com.example.servlet.web.frontcontroller.v4.controller.MemberFormControllerV4;
+import com.example.servlet.web.frontcontroller.v4.controller.MemberListControllerV4;
+import com.example.servlet.web.frontcontroller.v4.controller.MemberSaveControllerV4;
+
+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 = "frontControllerServletV4", urlPatterns = "/front-controller/v4/*")
+public class FrontControllerServletV4 extends HttpServlet {
+
+    private final Map<String, ControllerV4> controllerMap = new HashMap<>();
+
+    // 요청 URI 와 controller 매핑
+    public FrontControllerServletV4() {
+        controllerMap.put("/front-controller/v4/members/new-form", new MemberFormControllerV4());
+        controllerMap.put("/front-controller/v4/members/save", new MemberSaveControllerV4());
+        controllerMap.put("/front-controller/v4/members", new MemberListControllerV4());
+    }
+
+    @Override
+    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        String requestURI = request.getRequestURI(); // 요청 URI
+
+        ControllerV4 controller = controllerMap.get(requestURI);
+
+        if (controller == null) {
+            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
+            return;
+        }
+
+        // paramMap
+        Map<String, String> paramMap = createParamMap(request);
+        Map<String, Object> model = new HashMap<>();
+
+        String viewName = controller.process(paramMap, model);
+
+        MyView view = viewResolver(viewName); // 물리 이름
+
+        view.render(model, request, response);
+    }
+
+    // 논리 이름을 물리 이름으로 변환
+    private MyView viewResolver(String viewName) {
+        return new MyView("/WEB-INF/views/" + viewName + ".jsp");
+    }
+
+    // 넘어온 파라미터 값 꺼내기
+    private 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;
+    }
+}

spring-mvc/servlet/src/main/java/com/example/servlet/web/frontcontroller/v4/controller/MemberFormControllerV4.java

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+package com.example.servlet.web.frontcontroller.v4.controller;
+
+import com.example.servlet.web.frontcontroller.v4.ControllerV4;
+
+import java.util.Map;
+
+public class MemberFormControllerV4 implements ControllerV4 {
+    @Override
+    public String process(Map<String, String> paramMap, Map<String, Object> model) {
+        return "new-form";
+    }
+}

spring-mvc/servlet/src/main/java/com/example/servlet/web/frontcontroller/v4/controller/MemberListControllerV4.java

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+package com.example.servlet.web.frontcontroller.v4.controller;
+
+import com.example.servlet.domain.member.Member;
+import com.example.servlet.domain.member.MemberRepository;
+import com.example.servlet.web.frontcontroller.v4.ControllerV4;
+
+import java.util.List;
+import java.util.Map;
+
+public class MemberListControllerV4 implements ControllerV4 {
+
+    private final MemberRepository memberRepository = MemberRepository.getInstance();
+
+    @Override
+    public String process(Map<String, String> paramMap, Map<String, Object> model) {
+        List<Member> members = memberRepository.findAll();
+        model.put("members", members);
+        return "members";
+    }
+}

spring-mvc/servlet/src/main/java/com/example/servlet/web/frontcontroller/v4/controller/MemberSaveControllerV4.java

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+package com.example.servlet.web.frontcontroller.v4.controller;
+
+import com.example.servlet.domain.member.Member;
+import com.example.servlet.domain.member.MemberRepository;
+import com.example.servlet.web.frontcontroller.v4.ControllerV4;
+
+import java.util.Map;
+
+public class MemberSaveControllerV4 implements ControllerV4 {
+
+    private final MemberRepository memberRepository = MemberRepository.getInstance();
+
+    @Override
+    public String process(Map<String, String> paramMap, Map<String, Object> model) {
+        String username = paramMap.get("username");
+        int age = Integer.parseInt(paramMap.get("age"));
+
+        Member member = new Member(username, age);
+        memberRepository.save(member);
+
+        model.put("member", member);
+        return "save-result";
+    }
+}