[MVC 구현하기 - 2단계] 에버(손채영) 미션 제출합니다.

app/build.gradle

@@ -25,6 +25,7 @@ dependencies {
 
     testImplementation 'org.assertj:assertj-core:3.26.0'
     testImplementation 'org.mockito:mockito-core:5.12.0'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.10.2'
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.10.2'
     testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.10.2'
 }

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

@@ -1,12 +1,17 @@
 package com.techcourse;
 
 import com.interface21.webmvc.servlet.ModelAndView;
-import com.interface21.webmvc.servlet.View;
+import com.interface21.webmvc.servlet.mvc.asis.Controller;
+import com.interface21.webmvc.servlet.mvc.tobe.AnnotationHandlerMapping;
+import com.interface21.webmvc.servlet.mvc.tobe.HandlerExecution;
+import com.interface21.webmvc.servlet.mvc.tobe.HandlerMapping;
+import com.interface21.webmvc.servlet.mvc.tobe.HandlerMappingAdapter;
 import com.interface21.webmvc.servlet.view.JspView;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.util.Arrays;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -15,15 +20,18 @@ 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[] handlerMappings;
 
     public DispatcherServlet() {
     }
 
     @Override
     public void init() {
-        manualHandlerMapping = new ManualHandlerMapping();
-        manualHandlerMapping.initialize();
+        handlerMappings = new HandlerMapping[]{
+                new ManualHandlerMapping(),
+                new HandlerMappingAdapter(new AnnotationHandlerMapping())
+        };
+        Arrays.stream(handlerMappings).forEach(HandlerMapping::initialize);
     }
 
     @Override
@@ -33,14 +41,36 @@ 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);
-            ModelAndView modelAndView = new ModelAndView(new JspView(viewName));
-            View view = modelAndView.getView();
-            view.render(modelAndView.getModel(), request, response);
+            Object handler = getHandler(request);
+            ModelAndView modelAndView = execute(request, response, handler);
+            modelAndView.render(request, response);
         } catch (Throwable e) {
             log.error("Exception : {}", e.getMessage(), e);
             throw new ServletException(e.getMessage());
         }
     }
+
+    private Object getHandler(HttpServletRequest request) {
+        for (HandlerMapping handlerMapping : handlerMappings) {
+            Object handler = handlerMapping.getHandler(request);
+            if (handler != null) {
+                return handler;
+            }
+        }
+        throw new IllegalArgumentException("해당 요청을 처리하는 핸들러가 없습니다: %s %s"
+                .formatted(request.getMethod(), request.getRequestURI()));
+    }
+
+    private ModelAndView execute(HttpServletRequest request, HttpServletResponse response, Object handler)
+            throws Exception {
+        if (handler instanceof Controller) {
+            String viewName = ((Controller) handler).execute(request, response);
+            return new ModelAndView(JspView.from(viewName));
+        }
+        if (handler instanceof HandlerExecution) {
+            return ((HandlerExecution) handler).handle(request, response);
+        }
+        throw new IllegalArgumentException("해당 요청을 수행할 수 없습니다: %s %s"
+                .formatted(request.getMethod(), request.getRequestURI()));
+    }
 }

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

@@ -1,34 +1,39 @@
 package com.techcourse;
 
-import com.techcourse.controller.*;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import com.interface21.webmvc.servlet.mvc.asis.Controller;
 import com.interface21.webmvc.servlet.mvc.asis.ForwardController;
-
+import com.interface21.webmvc.servlet.mvc.tobe.HandlerMapping;
+import com.techcourse.controller.LoginController;
+import com.techcourse.controller.LoginViewController;
+import com.techcourse.controller.LogoutController;
+import jakarta.servlet.http.HttpServletRequest;
 import java.util.HashMap;
 import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-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()));
+        log.info("Initialized ManualHandlerMapping!");
+        ManualHandlerMapping.controllers.keySet()
+                .forEach(path -> log.info("Path : {}, Controller : {}", path,
+                        ManualHandlerMapping.controllers.get(path).getClass()));
     }
 
-    public Controller getHandler(final String requestURI) {
+    @Override
+    public Object 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

@@ -1,21 +1,30 @@
 package com.techcourse.controller;
 
+import com.interface21.context.stereotype.Controller;
+import com.interface21.web.bind.annotation.RequestMapping;
+import com.interface21.web.bind.annotation.RequestMethod;
+import com.interface21.webmvc.servlet.ModelAndView;
+import com.interface21.webmvc.servlet.view.JspView;
 import com.techcourse.domain.User;
 import com.techcourse.repository.InMemoryUserRepository;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-import com.interface21.webmvc.servlet.mvc.asis.Controller;
 
-public class RegisterController implements Controller {
+@Controller
+public class RegisterController {
 
-    @Override
-    public String execute(final HttpServletRequest req, final HttpServletResponse res) throws Exception {
-        final var user = new User(2,
+    @RequestMapping(value = "/register", method = RequestMethod.POST)
+    public ModelAndView save(HttpServletRequest req, HttpServletResponse res) {
+        User user = new User(2,
                 req.getParameter("account"),
                 req.getParameter("password"),
                 req.getParameter("email"));
         InMemoryUserRepository.save(user);
+        return new ModelAndView(JspView.from("/index.jsp"));
+    }
 
-        return "redirect:/index.jsp";
+    @RequestMapping(value = "/register", method = RequestMethod.GET)
+    public ModelAndView show(HttpServletRequest req, HttpServletResponse res) {
+        return new ModelAndView(JspView.from("/register.jsp"));
     }
 }

app/src/test/java/com/techcourse/HandlerMappingTest.java

@@ -0,0 +1,55 @@
+package com.techcourse;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.interface21.webmvc.servlet.mvc.tobe.AnnotationHandlerMapping;
+import com.interface21.webmvc.servlet.mvc.tobe.HandlerMappingAdapter;
+import jakarta.servlet.http.HttpServletRequest;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class HandlerMappingTest {
+
+    private ManualHandlerMapping manualHandlerMapping;
+    private HandlerMappingAdapter annotationHandlerMapping;
+
+    @BeforeEach
+    void setUp() {
+        manualHandlerMapping = new ManualHandlerMapping();
+        annotationHandlerMapping = new HandlerMappingAdapter(new AnnotationHandlerMapping());
+        manualHandlerMapping.initialize();
+        annotationHandlerMapping.initialize();
+    }
+
+    @DisplayName("@MVC로 구현된 요청이 들어올 경우 AnnotationHandlerMapping가 해당 요청을 처리한다.")
+    @ParameterizedTest
+    @ValueSource(strings = {"GET", "POST"})
+    void should_mapAnnotationHandlerMapping_when_NewMvc(String requestMethod) {
+        // given
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        when(request.getRequestURI()).thenReturn("/register");
+        when(request.getMethod()).thenReturn(requestMethod);
+
+        // when & then
+        assertThat(manualHandlerMapping.getHandler(request)).isNull();
+        assertThat(annotationHandlerMapping.getHandler(request)).isNotNull();
+    }
+
+    @DisplayName("Legacy MVC로 구현된 요청이 들어올 경우 ManualHandlerMapping가 해당 요청을 처리한다.")
+    @ParameterizedTest
+    @ValueSource(strings = {"/", "/login", "/login/view", "/logout"})
+    void should_mapManualHandlerMapping_when_LegacyMvc(String requestUri) {
+        // given
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        when(request.getRequestURI()).thenReturn(requestUri);
+        when(request.getMethod()).thenReturn("GET");
+
+        // when & then
+        assertThat(manualHandlerMapping.getHandler(request)).isNotNull();
+        assertThat(annotationHandlerMapping.getHandler(request)).isNull();
+    }
+}

app/src/test/java/com/techcourse/ManualHandlerMappingTest.java

@@ -0,0 +1,69 @@
+package com.techcourse;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.interface21.webmvc.servlet.mvc.asis.Controller;
+import com.interface21.webmvc.servlet.mvc.asis.ForwardController;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+class ManualHandlerMappingTest {
+
+    private ManualHandlerMapping handlerMapping;
+
+    @BeforeEach
+    void setUp() {
+        handlerMapping = new ManualHandlerMapping();
+    }
+
+    @DisplayName("초기화를 진행할 경우 직접 입력한 uri와 핸들러를 매핑한다.")
+    @Test
+    void should_mapControllers_when_init() {
+        // given
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        when(request.getRequestURI()).thenReturn("/");
+
+        // when
+        handlerMapping.initialize();
+
+        // then
+        Object actual = handlerMapping.getHandler(request);
+        assertThat(actual).isInstanceOf(ForwardController.class);
+    }
+
+    @DisplayName("해당 uri에 매핑되는 핸들러를 찾아 실행한다.")
+    @Test
+    void should_returnController_when_getHandlerWithIndexUri() throws Exception {
+        // given
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        HttpServletResponse response = mock(HttpServletResponse.class);
+        when(request.getRequestURI()).thenReturn("/");
+        handlerMapping.initialize();
+
+        // when
+        Controller controller = (Controller) handlerMapping.getHandler(request);
+        String viewName = controller.execute(request, response);
+
+        // then
+        assertThat(viewName).isEqualTo("/index.jsp");
+    }
+
+    @DisplayName("해당 uri에 매핑되는 핸들러가 없는 경우 null을 반환한다.")
+    @Test
+    void should_returnNull_when_getHandlerWithInvalidRequest() {
+        // given
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        when(request.getRequestURI()).thenReturn("/invalid");
+
+        // when
+        Object handler = handlerMapping.getHandler(request);
+
+        // then
+        assertThat(handler).isNull();
+    }
+}

mvc/src/main/java/com/interface21/webmvc/servlet/ModelAndView.java

@@ -1,5 +1,7 @@
 package com.interface21.webmvc.servlet;
 
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -14,6 +16,10 @@ public ModelAndView(final View view) {
         this.model = new HashMap<>();
     }
 
+    public void render(HttpServletRequest request, HttpServletResponse response) throws Exception {
+        view.render(model, request, response);
+    }
+
     public ModelAndView addObject(final String attributeName, final Object attributeValue) {
         model.put(attributeName, attributeValue);
         return this;

mvc/src/main/java/com/interface21/webmvc/servlet/mvc/tobe/AnnotationHandlerMapping.java

@@ -28,11 +28,21 @@ public AnnotationHandlerMapping(final Object... basePackage) {
         this.handlerExecutions = new HashMap<>();
     }
 
+    public AnnotationHandlerMapping() {
+        this.basePackage = new Object[]{"com.techcourse.controller"};
+        this.handlerExecutions = new HashMap<>();
+    }
+
     public void initialize() {
-        log.info("Initialized AnnotationHandlerMapping!");
         Reflections reflections = new Reflections(basePackage);
         Set<Class<?>> controllerTypes = reflections.getTypesAnnotatedWith(Controller.class);
         controllerTypes.forEach(this::mapControllerHandlers);
+
+        log.info("Initialized AnnotationHandlerMapping!");
+        handlerExecutions.keySet()
+                .forEach(handlerKey -> log.info("Path : {} {}, Controller : {}", handlerKey.requestMethod,
+                        handlerKey.url,
+                        handlerExecutions.get(handlerKey)));
     }
 
     private void mapControllerHandlers(Class<?> controllerType) {

mvc/src/main/java/com/interface21/webmvc/servlet/mvc/tobe/HandlerMapping.java

@@ -0,0 +1,10 @@
+package com.interface21.webmvc.servlet.mvc.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+public interface HandlerMapping {
+
+    void initialize();
+
+    Object getHandler(HttpServletRequest request);
+}

mvc/src/main/java/com/interface21/webmvc/servlet/mvc/tobe/HandlerMappingAdapter.java

@@ -0,0 +1,26 @@
+package com.interface21.webmvc.servlet.mvc.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+public class HandlerMappingAdapter implements HandlerMapping {
+
+    private final AnnotationHandlerMapping annotationHandlerMapping;
+
+    public HandlerMappingAdapter(AnnotationHandlerMapping annotationHandlerMapping) {
+        this.annotationHandlerMapping = annotationHandlerMapping;
+    }
+
+    @Override
+    public void initialize() {
+        annotationHandlerMapping.initialize();
+    }
+
+    @Override
+    public Object getHandler(HttpServletRequest request) {
+        try {
+            return annotationHandlerMapping.getHandler(request);
+        } catch (IllegalArgumentException e) {
+            return null;
+        }
+    }
+}