[MVC 구현하기 - 2단계] 후디(조동현) 미션 제출합니다.

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

@@ -2,7 +2,9 @@
 
 import jakarta.servlet.ServletContext;
 import nextstep.mvc.DispatcherServlet;
+import nextstep.mvc.controller.asis.ControllerHandlerAdapter;
 import nextstep.mvc.controller.tobe.AnnotationHandlerMapping;
+import nextstep.mvc.controller.tobe.HandlerExecutionHandlerAdapter;
 import nextstep.web.WebApplicationInitializer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -14,6 +16,9 @@ public class AppWebApplicationInitializer implements WebApplicationInitializer {
     @Override
     public void onStartup(final ServletContext servletContext) {
         final var dispatcherServlet = new DispatcherServlet();
+        dispatcherServlet.addHandlerAdapter(new ControllerHandlerAdapter());
+        dispatcherServlet.addHandlerAdapter(new HandlerExecutionHandlerAdapter());
+
         dispatcherServlet.addHandlerMapping(new ManualHandlerMapping());
         dispatcherServlet.addHandlerMapping(new AnnotationHandlerMapping("com.techcourse.controller"));
 

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

@@ -1,16 +1,17 @@
 package com.techcourse;
 
-import com.techcourse.controller.*;
+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 nextstep.mvc.HandlerMapping;
 import nextstep.mvc.controller.asis.Controller;
 import nextstep.mvc.controller.asis.ForwardController;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.HashMap;
-import java.util.Map;
-
 public class ManualHandlerMapping implements HandlerMapping {
 
     private static final Logger log = LoggerFactory.getLogger(ManualHandlerMapping.class);
@@ -23,8 +24,6 @@ public void initialize() {
         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()

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

@@ -4,18 +4,30 @@
 import com.techcourse.repository.InMemoryUserRepository;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-import nextstep.mvc.controller.asis.Controller;
+import nextstep.mvc.view.JspView;
+import nextstep.mvc.view.ModelAndView;
+import nextstep.web.annotation.Controller;
+import nextstep.web.annotation.RequestMapping;
+import nextstep.web.support.RequestMethod;
 
-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 save(HttpServletRequest req, HttpServletResponse res) {
         final var user = new User(2,
                 req.getParameter("account"),
                 req.getParameter("password"),
                 req.getParameter("email"));
         InMemoryUserRepository.save(user);
 
-        return "redirect:/index.jsp";
+        JspView jspView = new JspView("redirect:/index.jsp");
+        return new ModelAndView(jspView);
+    }
+
+    @RequestMapping(value = "/register/view", method = RequestMethod.GET)
+    public ModelAndView show(HttpServletRequest req, HttpServletResponse res) {
+        JspView jspView = new JspView("/register.jsp");
+        return new ModelAndView(jspView);
     }
 }

mvc/src/main/java/nextstep/mvc/DispatcherServlet.java

@@ -4,13 +4,7 @@
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import nextstep.mvc.controller.asis.Controller;
-import nextstep.mvc.controller.tobe.HandlerExecution;
-import nextstep.mvc.view.JspView;
+import nextstep.mvc.controller.tobe.exception.ControllerNotFoundException;
 import nextstep.mvc.view.ModelAndView;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -20,19 +14,24 @@ public class DispatcherServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;
     private static final Logger log = LoggerFactory.getLogger(DispatcherServlet.class);
 
-    private final List<HandlerMapping> handlerMappings;
+    private final HandlerAdapterRegistry handlerAdapterRegistry;
+    private final HandlerMappingRegistry handlerMappingRegistry;
 
     public DispatcherServlet() {
-        this.handlerMappings = new ArrayList<>();
+        this.handlerAdapterRegistry = new HandlerAdapterRegistry();
+        this.handlerMappingRegistry = new HandlerMappingRegistry();
     }
 
     @Override
     public void init() {
-        handlerMappings.forEach(HandlerMapping::initialize);
+    }
+
+    public void addHandlerAdapter(final HandlerAdapter handlerAdapter) {
+        handlerAdapterRegistry.addHandlerAdapter(handlerAdapter);
     }
 
     public void addHandlerMapping(final HandlerMapping handlerMapping) {
-        handlerMappings.add(handlerMapping);
+        handlerMappingRegistry.addHandlerMapping(handlerMapping);
     }
 
     @Override
@@ -41,41 +40,15 @@ protected void service(final HttpServletRequest request, final HttpServletRespon
         log.debug("Method : {}, Request URI : {}", request.getMethod(), request.getRequestURI());
 
         try {
-            final Object controller = getController(request);
-
-            // TODO: 다형성을 통해 해결해야함
-            if (controller instanceof HandlerExecution) {
-                HandlerExecution handlerExecution = (HandlerExecution) controller;
-                ModelAndView modelAndView = handlerExecution.handle(request, response);
-                Map<String, Object> model = modelAndView.getModel();
-                modelAndView.getView().render(model, request, response);
-                return;
-            }
+            Object controller = handlerMappingRegistry.getHandler(request)
+                    .orElseThrow(ControllerNotFoundException::new);
 
-            final var viewName = ((Controller) controller).execute(request, response);
-            move(viewName, request, response);
+            HandlerAdapter handlerAdapter = handlerAdapterRegistry.getHandlerAdapter(controller);
+            ModelAndView modelAndView = handlerAdapter.handle(request, response, controller);
+            modelAndView.render(request, response);
         } catch (Throwable e) {
             log.error("Exception : {}", e.getMessage(), e);
             throw new ServletException(e.getMessage());
         }
     }
-
-    private Object getController(final HttpServletRequest request) {
-        return handlerMappings.stream()
-                .map(handlerMapping -> handlerMapping.getHandler(request))
-                .filter(Objects::nonNull)
-                .findFirst()
-                .orElseThrow();
-    }
-
-    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);
-    }
 }

mvc/src/main/java/nextstep/mvc/HandlerAdapterRegistry.java

@@ -0,0 +1,25 @@
+package nextstep.mvc;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class HandlerAdapterRegistry {
+
+    private final List<HandlerAdapter> handlerAdapters;
+
+    public HandlerAdapterRegistry() {
+        this.handlerAdapters = new ArrayList<>();
+    }
+
+    public void addHandlerAdapter(final HandlerAdapter handlerAdapter) {
+        handlerAdapters.add(handlerAdapter);
+    }
+
+    public HandlerAdapter getHandlerAdapter(final Object handler) {
+        return handlerAdapters.stream()
+                .filter(it -> it.supports(handler))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("지원하지 않는 핸들러입니다."));
+        // TODO: 적절한 예외로 변경
+    }
+}

mvc/src/main/java/nextstep/mvc/HandlerMappingRegistry.java

@@ -0,0 +1,28 @@
+package nextstep.mvc;
+
+import jakarta.servlet.http.HttpServletRequest;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+public class HandlerMappingRegistry {
+
+    private final List<HandlerMapping> handlerMappings;
+
+    public HandlerMappingRegistry() {
+        handlerMappings = new ArrayList<>();
+    }
+
+    public void addHandlerMapping(final HandlerMapping handlerMapping) {
+        handlerMapping.initialize();
+        handlerMappings.add(handlerMapping);
+    }
+
+    public Optional<Object> getHandler(final HttpServletRequest request) {
+        return handlerMappings.stream()
+                .map(handlerMapping -> handlerMapping.getHandler(request))
+                .filter(Objects::nonNull)
+                .findFirst();
+    }
+}

mvc/src/main/java/nextstep/mvc/controller/asis/ControllerHandlerAdapter.java

@@ -0,0 +1,23 @@
+package nextstep.mvc.controller.asis;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import nextstep.mvc.HandlerAdapter;
+import nextstep.mvc.view.JspView;
+import nextstep.mvc.view.ModelAndView;
+
+public class ControllerHandlerAdapter implements HandlerAdapter {
+
+    @Override
+    public boolean supports(final Object handler) {
+        return handler instanceof Controller;
+    }
+
+    @Override
+    public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response,
+                               final Object handler) throws Exception {
+        String viewName = ((Controller) handler).execute(request, response);
+        JspView jspView = new JspView(viewName);
+        return new ModelAndView(jspView);
+    }
+}

mvc/src/main/java/nextstep/mvc/controller/tobe/AnnotationHandlerMapping.java

@@ -6,14 +6,9 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.stream.Collectors;
 import nextstep.mvc.HandlerMapping;
-import nextstep.mvc.controller.tobe.exception.ControllerNotFoundException;
-import nextstep.web.annotation.Controller;
 import nextstep.web.annotation.RequestMapping;
-import org.reflections.Reflections;
-import org.reflections.scanners.Scanners;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -30,8 +25,9 @@ public AnnotationHandlerMapping(final Object... basePackage) {
     }
 
     public void initialize() {
-        Set<Class<?>> controllerClasses = extractClasses();
-        List<Method> methods = extractMethods(controllerClasses);
+        ControllerScanner controllerScanner = new ControllerScanner();
+        Map<Class<?>, Object> controllers = controllerScanner.getControllers(basePackage);
+        List<Method> methods = extractMethods(controllers);
 
         for (Method method : methods) {
             addHandlerExecutions(method);
@@ -40,13 +36,8 @@ public void initialize() {
         log.info("Initialized AnnotationHandlerMapping!");
     }
 
-    private Set<Class<?>> extractClasses() {
-        Reflections classReflections = new Reflections(basePackage, Scanners.TypesAnnotated);
-        return classReflections.getTypesAnnotatedWith(Controller.class);
-    }
-
-    private List<Method> extractMethods(final Set<Class<?>> controllers) {
-        return controllers.stream()
+    private List<Method> extractMethods(final Map<Class<?>, Object> controllers) {
+        return controllers.keySet().stream()
                 .flatMap(it -> Arrays.stream(it.getMethods()))
                 .filter(it -> it.isAnnotationPresent(RequestMapping.class))
                 .collect(Collectors.toList());
@@ -62,14 +53,8 @@ private void addHandlerExecutions(final Method method) {
         }
     }
 
-    public Object getHandler(final HttpServletRequest request) {
+    public HandlerExecution getHandler(final HttpServletRequest request) {
         HandlerKey handlerKey = new HandlerKey(request);
-        HandlerExecution handlerExecution = handlerExecutions.get(handlerKey);
-
-        if (handlerExecution == null) {
-            throw new ControllerNotFoundException();
-        }
-
-        return handlerExecution;
+        return handlerExecutions.get(handlerKey);
     }
 }

mvc/src/main/java/nextstep/mvc/controller/tobe/ControllerScanner.java

@@ -0,0 +1,32 @@
+package nextstep.mvc.controller.tobe;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import nextstep.web.annotation.Controller;
+import org.reflections.Reflections;
+import org.reflections.scanners.Scanners;
+
+public class ControllerScanner {
+
+    public Map<Class<?>, Object> getControllers(final Object[] basePackage) {
+        Reflections classReflections = new Reflections(basePackage, Scanners.TypesAnnotated);
+        Set<Class<?>> classes = classReflections.getTypesAnnotatedWith(Controller.class);
+
+        return instantiateControllers(classes);
+    }
+
+    private Map<Class<?>, Object> instantiateControllers(final Set<Class<?>> classes) {
+        return classes.stream()
+                .collect(Collectors.toMap(clazz -> clazz, this::instantiateClass));
+    }
+
+    private Object instantiateClass(final Class<?> clazz) {
+        try {
+            return clazz.getConstructor().newInstance();
+        } catch (ReflectiveOperationException e) {
+            throw new IllegalArgumentException("Controller를 인스턴스화 할 수 없습니다.");
+            // TODO: 적절한 예외를 던져야함
+        }
+    }
+}

mvc/src/main/java/nextstep/mvc/controller/tobe/HandlerExecutionHandlerAdapter.java

@@ -0,0 +1,20 @@
+package nextstep.mvc.controller.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import nextstep.mvc.HandlerAdapter;
+import nextstep.mvc.view.ModelAndView;
+
+public class HandlerExecutionHandlerAdapter implements HandlerAdapter {
+
+    @Override
+    public boolean supports(final Object handler) {
+        return handler instanceof HandlerExecution;
+    }
+
+    @Override
+    public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response,
+                               final Object handler) throws Exception {
+        return ((HandlerExecution) handler).handle(request, response);
+    }
+}