[MVC 구현하기 - 2단계] 하마드(이건회) 미션 제출합니다! ⚽️ (#505)

* refactor : 인스턴스화시 예외처리 런타임으로 변환

* refactor : RequestMethod 변환 기능 내장함수로 대체

* feat : 어노테이션 기반 컨트롤러 공존

* refactor : swtich-case 기반 정적메소드 변경

* feat : 로그인, 회원가입 컨트롤러 어노테이션 기반으로 처리

app/build.gradle

@@ -21,6 +21,7 @@ dependencies {
     implementation "org.apache.tomcat.embed:tomcat-embed-jasper:10.1.13"
     implementation "ch.qos.logback:logback-classic:1.2.12"
     implementation "org.apache.commons:commons-lang3:3.13.0"
+    implementation "org.reflections:reflections:0.10.2"
 
     testImplementation "org.assertj:assertj-core:3.24.2"
     testImplementation "org.junit.jupiter:junit-jupiter-api:5.7.2"

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

@@ -1,27 +1,51 @@
 package com.techcourse;
 
+import com.techcourse.handlerMapper.AnnotationHandlerAdapter;
+import com.techcourse.handlerMapper.AnnotationHandlerMapping;
+import com.techcourse.handlerMapper.HandlerAdapter;
+import com.techcourse.handlerMapper.HandlerMapping;
+import com.techcourse.handlerMapper.ManualHandlerAdapter;
+import com.techcourse.handlerMapper.ManualHandlerMapping;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 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 java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
 
 public class DispatcherServlet extends HttpServlet {
 
     private static final long serialVersionUID = 1L;
     private static final Logger log = LoggerFactory.getLogger(DispatcherServlet.class);
-
-    private ManualHandlerMapping manualHandlerMapping;
+    private List<HandlerMapping> handlerMappings = new ArrayList<>();
+    private List<HandlerAdapter> handlerAdapters = new ArrayList<>();
 
     public DispatcherServlet() {
     }
 
     @Override
     public void init() {
-        manualHandlerMapping = new ManualHandlerMapping();
-        manualHandlerMapping.initialize();
+        initHandlerMapping();
+        initHandlerAdapter();
+    }
+
+    private void initHandlerMapping() {
+        handlerMappings.add(new ManualHandlerMapping());
+        handlerMappings.add(new AnnotationHandlerMapping("com.techcourse.controller"));
+        for (HandlerMapping handlerMapping : handlerMappings) {
+            handlerMapping.initialize();
+        }
+    }
+
+    private void initHandlerAdapter() {
+        handlerAdapters.add(new AnnotationHandlerAdapter());
+        handlerAdapters.add(new ManualHandlerAdapter());
     }
 
     @Override
@@ -30,22 +54,23 @@ protected void service(final HttpServletRequest request, final HttpServletRespon
         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 = handlerMappings.stream()
+                    .map(handlerMapping -> handlerMapping.getHandler(request))
+                    .filter(Objects::nonNull)
+                    .findFirst()
+                    .orElseThrow(() -> new RuntimeException());
+
+            HandlerAdapter handlerAdapter = handlerAdapters.stream()
+                    .filter(adapter -> adapter.supports(handler))
+                    .findAny()
+                    .orElseThrow(() -> new RuntimeException());
+
+            ModelAndView modelAndView = handlerAdapter.handle(request, response, handler);
+            View view = modelAndView.getView();
+            view.render(modelAndView.getModel(), request, response);
         } catch (Throwable e) {
             log.error("Exception : {}", e.getMessage(), e);
             throw new ServletException(e.getMessage());
         }
     }
-
-    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;
-        }
-
-        final var requestDispatcher = request.getRequestDispatcher(viewName);
-        requestDispatcher.forward(request, response);
-    }
 }

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

@@ -2,36 +2,41 @@
 
 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 webmvc.org.springframework.web.servlet.mvc.asis.Controller;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+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;
 
-public class LoginController implements Controller {
+@Controller
+public class LoginController {
 
-    private static final Logger log = LoggerFactory.getLogger(LoginController.class);
-
-    @Override
-    public String execute(final HttpServletRequest req, final HttpServletResponse res) throws Exception {
-        if (UserSession.isLoggedIn(req.getSession())) {
-            return "redirect:/index.jsp";
+    @RequestMapping(value = "/login/view", method = RequestMethod.GET)
+    public ModelAndView showPage(HttpServletRequest request, HttpServletResponse response) {
+        if (UserSession.isLoggedIn(request.getSession())) {
+            return new ModelAndView(new JspView("redirect:/index.jsp"));
         }
+        return new ModelAndView(new JspView("/login.jsp"));
+    }
 
-        return InMemoryUserRepository.findByAccount(req.getParameter("account"))
-                .map(user -> {
-                    log.info("User : {}", user);
-                    return login(req, user);
-                })
-                .orElse("redirect:/401.jsp");
+    @RequestMapping(value = "/login", method = RequestMethod.POST)
+    public ModelAndView login(HttpServletRequest request, HttpServletResponse response) {
+        if (UserSession.isLoggedIn(request.getSession())) {
+            return new ModelAndView(new JspView("redirect:/index.jsp"));
+        }
+        return InMemoryUserRepository.findByAccount(request.getParameter("account"))
+                .map(user -> login(request, user))
+                .orElse(new ModelAndView(new JspView("redirect:/401.jsp")));
     }
 
-    private String login(final HttpServletRequest request, final User user) {
+    private ModelAndView login(final HttpServletRequest request, final User user) {
         if (user.checkPassword(request.getParameter("password"))) {
             final var session = request.getSession();
             session.setAttribute(UserSession.SESSION_KEY, user);
-            return "redirect:/index.jsp";
+            return new ModelAndView(new JspView("redirect:/index.jsp"));
         }
-        return "redirect:/401.jsp";
+        return new ModelAndView(new JspView("redirect:/401.jsp"));
     }
 }

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

@@ -2,20 +2,29 @@
 
 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 webmvc.org.springframework.web.servlet.mvc.asis.Controller;
+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;
 
-public class RegisterController implements Controller {
+@Controller
+public class RegisterController {
 
-    @Override
-    public String execute(final HttpServletRequest req, final HttpServletResponse res) throws Exception {
+    @RequestMapping(value = "/register", method = RequestMethod.POST)
+    public ModelAndView register(HttpServletRequest request, HttpServletResponse response) {
         final var user = new User(2,
-                req.getParameter("account"),
-                req.getParameter("password"),
-                req.getParameter("email"));
+                request.getParameter("account"),
+                request.getParameter("password"),
+                request.getParameter("email"));
         InMemoryUserRepository.save(user);
+        return new ModelAndView(new JspView("redirect:/index.jsp"));
+    }
 
-        return "redirect:/index.jsp";
+    @RequestMapping(value = "/register/view", method = RequestMethod.GET)
+    public ModelAndView showPage(HttpServletRequest request, HttpServletResponse response) {
+        return new ModelAndView(new JspView("/register.jsp"));
     }
 }

app/src/main/java/com/techcourse/handlerMapper/AnnotationHandlerAdapter.java

@@ -0,0 +1,18 @@
+package com.techcourse.handlerMapper;
+
+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.HandlerExecution;
+
+public class AnnotationHandlerAdapter implements HandlerAdapter {
+    @Override
+    public boolean supports(Object handler) {
+        return handler instanceof HandlerExecution;
+    }
+
+    @Override
+    public ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
+        return ((HandlerExecution) handler).handle(request, response);
+    }
+}

app/src/main/java/com/techcourse/handlerMapper/AnnotationHandlerMapping.java

@@ -0,0 +1,62 @@
+package com.techcourse.handlerMapper;
+
+import context.org.springframework.stereotype.Controller;
+import jakarta.servlet.http.HttpServletRequest;
+import org.reflections.Reflections;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import web.org.springframework.web.bind.annotation.RequestMapping;
+import web.org.springframework.web.bind.annotation.RequestMethod;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerExecution;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerKey;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+public class AnnotationHandlerMapping implements HandlerMapping {
+
+    private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
+
+    private final Object[] basePackage;
+    private final Map<HandlerKey, HandlerExecution> handlerExecutions;
+
+    public AnnotationHandlerMapping(final Object... basePackage) {
+        this.basePackage = basePackage;
+        this.handlerExecutions = new HashMap<>();
+    }
+
+    @Override
+    public void initialize() {
+        Reflections reflections = new Reflections(basePackage);
+        Set<Class<?>> controllers = reflections.getTypesAnnotatedWith(Controller.class);
+        for (Class<?> controller : controllers) {
+            Method[] methods = controller.getDeclaredMethods();
+            for (Method method : methods) {
+                if (method.isAnnotationPresent(RequestMapping.class)) {
+                    RequestMapping annotation = method.getAnnotation(RequestMapping.class);
+                    String url = annotation.value();
+                    for (RequestMethod requestMethod : annotation.method()) {
+                        Object instance = null;
+                        try {
+                            instance = controller.getDeclaredConstructor().newInstance();
+                        } catch (Exception e) {
+                            throw new RuntimeException(e);
+                        }
+                        HandlerKey handlerKey = new HandlerKey(url, requestMethod);
+                        HandlerExecution handlerExecution = new HandlerExecution(instance, method);
+                        handlerExecutions.put(handlerKey, handlerExecution);
+                    }
+                }
+            }
+        }
+        log.info("Initialized AnnotationHandlerMapping!");
+    }
+
+    @Override
+    public Object getHandler(final HttpServletRequest request) {
+        HandlerKey handlerKey = new HandlerKey(request.getRequestURI(), RequestMethod.resolve(request.getMethod()));
+        return handlerExecutions.get(handlerKey);
+    }
+}

app/src/main/java/com/techcourse/handlerMapper/HandlerAdapter.java

@@ -0,0 +1,12 @@
+package com.techcourse.handlerMapper;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+
+public interface HandlerAdapter {
+
+    boolean supports(Object handler);
+
+    ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception;
+}

app/src/main/java/com/techcourse/handlerMapper/HandlerMapping.java

@@ -0,0 +1,10 @@
+package com.techcourse.handlerMapper;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+public interface HandlerMapping {
+
+    void initialize();
+
+    Object getHandler(HttpServletRequest request);
+}

app/src/main/java/com/techcourse/handlerMapper/ManualHandlerAdapter.java

@@ -0,0 +1,20 @@
+package com.techcourse.handlerMapper;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
+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 viewName = ((Controller) handler).execute(request, response);
+        return new ModelAndView(new JspView(viewName));
+    }
+}

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

@@ -1,6 +1,7 @@
-package com.techcourse;
+package com.techcourse.handlerMapper;
 
-import com.techcourse.controller.*;
+import com.techcourse.controller.LogoutController;
+import jakarta.servlet.http.HttpServletRequest;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
@@ -9,27 +10,25 @@
 import java.util.HashMap;
 import java.util.Map;
 
-public class ManualHandlerMapping {
+public class ManualHandlerMapping implements HandlerMapping {
 
     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()));
     }
 
-    public Controller getHandler(final String requestURI) {
-        log.debug("Request Mapping Uri : {}", requestURI);
-        return controllers.get(requestURI);
+    @Override
+    public Controller getHandler(HttpServletRequest request) {
+        log.debug("Request Mapping Uri : {}", request.getRequestURI());
+        return controllers.get(request.getRequestURI());
     }
 }