[MVC 미션 2단계] 오리(오현서) 미션 제출합니다. (#451)

* refactor: RequestMapping Method default 값 추가

* refactor: Handler가 null이면 throws

* refactor: 메소드명 변경

* refactor: 메소드명 변경

* feat: Register 로직을 annotation으로 처리

* refactor: HandlerMapping 인터페이스 추가

* refactor: HandlerMappings 일급 컬렉션 활용하도록 변경

* feat: HandlerAdapter 추가

* refactor: HandelrAdpaters - > HandlerAdapterFinder 클래스명 변경

* refactor: 핸들러 찾지 못할 시 예외

* refactor: 가독성 개선

* feat: 예외 처리 추가

* chore: 패키지 분리

* refactor: 개행, 컨벤션등 수정

* refactor: HandlerMappings -> HandlerMappingComposite 변경

* chore: ManualHandlerAdapter 패키지 변경

* refactor: AnnotationHandlerMapping의 패키지 스캔 범위 구체화

* refactor: 예외 처리 로직 메소드 추출

Author: carsago

app/src/main/java/com/techcourse/DispatcherServlet.java

@@ -4,48 +4,80 @@
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import webmvc.org.springframework.web.servlet.view.JspView;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.View;
+import webmvc.org.springframework.web.servlet.mvc.asis.ManualHandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.adapter.AnnotationHandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.adapter.HandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.adapter.HandlerAdapterFinder;
+import webmvc.org.springframework.web.servlet.mvc.tobe.exception.ExceptionResolver;
+import webmvc.org.springframework.web.servlet.mvc.tobe.handler.AnnotationHandlerMapping;
+import webmvc.org.springframework.web.servlet.mvc.tobe.handler.HandlerMapping;
+import webmvc.org.springframework.web.servlet.mvc.tobe.handler.HandlerMappingComposite;
 
 public class DispatcherServlet extends HttpServlet {
 
     private static final long serialVersionUID = 1L;
     private static final Logger log = LoggerFactory.getLogger(DispatcherServlet.class);
 
-    private ManualHandlerMapping manualHandlerMapping;
+    private HandlerMapping handlerMapping;
+    private HandlerAdapterFinder handlerAdapterFinder;
+    private ExceptionResolver exceptionResolver;
 
     public DispatcherServlet() {
     }
 
     @Override
     public void init() {
-        manualHandlerMapping = new ManualHandlerMapping();
-        manualHandlerMapping.initialize();
+        handlerMapping = initHandlerMappings();
+        handlerAdapterFinder = initHandlerAdapterFinder();
+        exceptionResolver = new ExceptionResolver();
+    }
+
+    private HandlerMapping initHandlerMappings() {
+        HandlerMapping handlerMapping = new HandlerMappingComposite(
+            List.of(new ManualHandlerMapping(), new AnnotationHandlerMapping("com.techcourse.controller")));
+        handlerMapping.initialize();
+        return handlerMapping;
+    }
+
+    private HandlerAdapterFinder initHandlerAdapterFinder() {
+        return new HandlerAdapterFinder(
+            List.of(new ManualHandlerAdapter(), new AnnotationHandlerAdapter()));
     }
 
     @Override
-    protected void service(final HttpServletRequest request, final HttpServletResponse response) throws ServletException {
+    protected void service(final HttpServletRequest request, final HttpServletResponse response)
+        throws ServletException {
         final String requestURI = request.getRequestURI();
         log.debug("Method : {}, Request URI : {}", request.getMethod(), requestURI);
-
         try {
-            final var controller = manualHandlerMapping.getHandler(requestURI);
-            final var viewName = controller.execute(request, response);
-            move(viewName, request, response);
+            Object handler = handlerMapping.getHandler(request);
+            HandlerAdapter handlerAdapter = handlerAdapterFinder.find(handler);
+            ModelAndView mv = handlerAdapter.handle(request, response, handler);
+            render(request, response, mv);
         } catch (Throwable e) {
-            log.error("Exception : {}", e.getMessage(), e);
-            throw new ServletException(e.getMessage());
+            handleException(request, response, e);
         }
     }
 
-    private void move(final String viewName, final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        if (viewName.startsWith(JspView.REDIRECT_PREFIX)) {
-            response.sendRedirect(viewName.substring(JspView.REDIRECT_PREFIX.length()));
-            return;
-        }
+    private void render(HttpServletRequest request, HttpServletResponse response, ModelAndView modelAndView)
+        throws Exception {
+        View view = modelAndView.getView();
+        view.render(modelAndView.getModel(), request, response);
+    }
 
-        final var requestDispatcher = request.getRequestDispatcher(viewName);
-        requestDispatcher.forward(request, response);
+    private void handleException(HttpServletRequest request, HttpServletResponse response, Throwable e)
+        throws ServletException {
+        ModelAndView mv = exceptionResolver.handle(e);
+        try {
+            render(request, response, mv);
+        } catch (Exception ex) {
+            log.error("Exception : {}", e.getMessage(), e);
+            throw new ServletException(e.getMessage());
+        }
     }
 }

app/src/main/java/com/techcourse/ManualHandlerMapping.java

@@ -1,34 +1,38 @@
 package com.techcourse;
 
-import com.techcourse.controller.*;
+import com.techcourse.controller.manual.LoginController;
+import com.techcourse.controller.manual.LoginViewController;
+import com.techcourse.controller.manual.LogoutController;
+import jakarta.servlet.http.HttpServletRequest;
+import java.util.HashMap;
+import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
 import webmvc.org.springframework.web.servlet.mvc.asis.ForwardController;
+import webmvc.org.springframework.web.servlet.mvc.tobe.handler.HandlerMapping;
 
-import java.util.HashMap;
-import java.util.Map;
-
-public class ManualHandlerMapping {
+public class ManualHandlerMapping implements HandlerMapping<Controller> {
 
     private static final Logger log = LoggerFactory.getLogger(ManualHandlerMapping.class);
 
     private static final Map<String, Controller> controllers = new HashMap<>();
 
+    @Override
     public void initialize() {
         controllers.put("/", new ForwardController("/index.jsp"));
         controllers.put("/login", new LoginController());
         controllers.put("/login/view", new LoginViewController());
         controllers.put("/logout", new LogoutController());
-        controllers.put("/register/view", new RegisterViewController());
-        controllers.put("/register", new RegisterController());
 
         log.info("Initialized Handler Mapping!");
         controllers.keySet()
-                .forEach(path -> log.info("Path : {}, Controller : {}", path, controllers.get(path).getClass()));
+            .forEach(path -> log.info("Path : {}, Controller : {}", path, controllers.get(path).getClass()));
     }
 
-    public Controller getHandler(final String requestURI) {
+    @Override
+    public Controller getHandler(final HttpServletRequest request) {
+        String requestURI = request.getRequestURI();
         log.debug("Request Mapping Uri : {}", requestURI);
         return controllers.get(requestURI);
     }

app/src/main/java/com/techcourse/controller/RegisterController.java

@@ -0,0 +1,31 @@
+package com.techcourse.controller.annotation;
+
+import com.techcourse.domain.User;
+import com.techcourse.repository.InMemoryUserRepository;
+import context.org.springframework.stereotype.Controller;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import web.org.springframework.web.bind.annotation.RequestMapping;
+import web.org.springframework.web.bind.annotation.RequestMethod;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.view.JspView;
+
+@Controller
+public class RegisterController {
+
+    @RequestMapping(value = "/register", method = RequestMethod.POST)
+    public ModelAndView save(HttpServletRequest req, HttpServletResponse res) {
+        final var user = new User(2,
+            req.getParameter("account"),
+            req.getParameter("password"),
+            req.getParameter("email"));
+        InMemoryUserRepository.save(user);
+
+        return new ModelAndView(new JspView("redirect:/index.jsp"));
+    }
+
+    @RequestMapping(value = "/register", method = RequestMethod.GET)
+    public ModelAndView show(HttpServletRequest req, HttpServletResponse res) {
+        return new ModelAndView(new JspView("/register.jsp"));
+    }
+}

app/src/main/java/com/techcourse/controller/RegisterViewController.java

@@ -1,12 +1,13 @@
-package com.techcourse.controller;
+package com.techcourse.controller.manual;
 
+import com.techcourse.controller.UserSession;
 import com.techcourse.domain.User;
 import com.techcourse.repository.InMemoryUserRepository;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
 
 public class LoginController implements Controller {
 

app/src/main/java/com/techcourse/controller/annotation/RegisterController.java

@@ -1,5 +1,6 @@
-package com.techcourse.controller;
+package com.techcourse.controller.manual;
 
+import com.techcourse.controller.UserSession;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;

app/src/main/java/com/techcourse/controller/LoginController.java renamed to app/src/main/java/com/techcourse/controller/manual/LoginController.java

@@ -1,5 +1,6 @@
-package com.techcourse.controller;
+package com.techcourse.controller.manual;
 
+import com.techcourse.controller.UserSession;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import webmvc.org.springframework.web.servlet.mvc.asis.Controller;

app/src/main/java/com/techcourse/controller/LoginViewController.java renamed to app/src/main/java/com/techcourse/controller/manual/LoginViewController.java

@@ -10,5 +10,5 @@
 public @interface RequestMapping {
     String value() default "";
 
-    RequestMethod[] method() default {};
+    RequestMethod[] method() default {RequestMethod.GET};
 }

app/src/main/java/com/techcourse/controller/LogoutController.java renamed to app/src/main/java/com/techcourse/controller/manual/LogoutController.java

@@ -0,0 +1,23 @@
+package webmvc.org.springframework.web.servlet.mvc.asis;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.mvc.tobe.adapter.HandlerAdapter;
+import webmvc.org.springframework.web.servlet.view.JspView;
+
+public class ManualHandlerAdapter implements HandlerAdapter {
+
+    @Override
+    public boolean supports(Object handler) {
+        return handler instanceof Controller;
+    }
+
+    @Override
+    public ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
+        throws Exception {
+        String responseURI = ((Controller) handler).execute(request, response);
+        ModelAndView modelAndView = new ModelAndView(new JspView(responseURI));
+        return modelAndView;
+    }
+}