[MVC 구현하기 - 1단계] 후디(조동현) 미션 제출합니다.

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

@@ -2,6 +2,7 @@
 
 import jakarta.servlet.ServletContext;
 import nextstep.mvc.DispatcherServlet;
+import nextstep.mvc.controller.tobe.AnnotationHandlerMapping;
 import nextstep.web.WebApplicationInitializer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -14,6 +15,7 @@ public class AppWebApplicationInitializer implements WebApplicationInitializer {
     public void onStartup(final ServletContext servletContext) {
         final var dispatcherServlet = new DispatcherServlet();
         dispatcherServlet.addHandlerMapping(new ManualHandlerMapping());
+        dispatcherServlet.addHandlerMapping(new AnnotationHandlerMapping("com.techcourse.controller"));
 
         final var dispatcher = servletContext.addServlet("dispatcher", dispatcherServlet);
         dispatcher.setLoadOnStartup(1);

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

@@ -4,15 +4,17 @@
 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.view.ModelAndView;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Objects;
-
 public class DispatcherServlet extends HttpServlet {
 
     private static final long serialVersionUID = 1L;
@@ -34,29 +36,40 @@ public void addHandlerMapping(final HandlerMapping handlerMapping) {
     }
 
     @Override
-    protected void service(final HttpServletRequest request, final HttpServletResponse response) throws ServletException {
+    protected void service(final HttpServletRequest request, final HttpServletResponse response)
+            throws ServletException {
         log.debug("Method : {}, Request URI : {}", request.getMethod(), request.getRequestURI());
 
         try {
-            final var controller = getController(request);
-            final var viewName = controller.execute(request, response);
+            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;
+            }
+
+            final var viewName = ((Controller) controller).execute(request, response);
             move(viewName, request, response);
         } catch (Throwable e) {
             log.error("Exception : {}", e.getMessage(), e);
             throw new ServletException(e.getMessage());
         }
     }
 
-    private Controller getController(final HttpServletRequest request) {
+    private Object getController(final HttpServletRequest request) {
         return handlerMappings.stream()
                 .map(handlerMapping -> handlerMapping.getHandler(request))
                 .filter(Objects::nonNull)
-                .map(Controller.class::cast)
                 .findFirst()
                 .orElseThrow();
     }
 
-    private void move(final String viewName, final HttpServletRequest request, final HttpServletResponse response) throws Exception {
+    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;

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

@@ -1,13 +1,22 @@
 package nextstep.mvc.controller.tobe;
 
 import jakarta.servlet.http.HttpServletRequest;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+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;
 
-import java.util.HashMap;
-import java.util.Map;
-
 public class AnnotationHandlerMapping implements HandlerMapping {
 
     private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
@@ -21,10 +30,46 @@ public AnnotationHandlerMapping(final Object... basePackage) {
     }
 
     public void initialize() {
+        Set<Class<?>> controllerClasses = extractClasses();
+        List<Method> methods = extractMethods(controllerClasses);
+
+        for (Method method : methods) {
+            addHandlerExecutions(method);
+        }
+
         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()
+                .flatMap(it -> Arrays.stream(it.getMethods()))
+                .filter(it -> it.isAnnotationPresent(RequestMapping.class))
+                .collect(Collectors.toList());
+    }
+
+    private void addHandlerExecutions(final Method method) {
+        RequestMapping requestMapping = method.getAnnotation(RequestMapping.class);
+        List<HandlerKey> handlerKeys = HandlerKey.from(requestMapping);
+        HandlerExecution handlerExecution = new HandlerExecution(method);
+
+        for (HandlerKey handlerKey : handlerKeys) {
+            handlerExecutions.put(handlerKey, handlerExecution);
+        }
+    }
+
     public Object getHandler(final HttpServletRequest request) {
-        return null;
+        HandlerKey handlerKey = new HandlerKey(request);
+        HandlerExecution handlerExecution = handlerExecutions.get(handlerKey);
+
+        if (handlerExecution == null) {
+            throw new ControllerNotFoundException();
+        }
+
+        return handlerExecution;
     }
 }

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

@@ -2,11 +2,24 @@
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
 import nextstep.mvc.view.ModelAndView;
 
 public class HandlerExecution {
 
+    private final Class<?> controller;
+    private final Method method;
+
+    public HandlerExecution(final Method method) {
+        this.controller = method.getDeclaringClass();
+        this.method = method;
+    }
+
     public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        return null;
+        Constructor<?> constructor = controller.getConstructor();
+        Object instance = constructor.newInstance();
+
+        return (ModelAndView) method.invoke(instance, request, response);
     }
 }

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

@@ -1,8 +1,13 @@
 package nextstep.mvc.controller.tobe;
 
-import nextstep.web.support.RequestMethod;
-
+import jakarta.servlet.http.HttpServletRequest;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
+import nextstep.web.annotation.RequestMapping;
+import nextstep.web.support.RequestMethod;
 
 public class HandlerKey {
 
@@ -14,6 +19,28 @@ public HandlerKey(final String url, final RequestMethod requestMethod) {
         this.requestMethod = requestMethod;
     }
 
+    public HandlerKey(final HttpServletRequest request) {
+        String url = request.getRequestURI();
+        RequestMethod requestMethod = RequestMethod.valueOf(request.getMethod());
+
+        this.url = url;
+        this.requestMethod = requestMethod;
+    }
+
+    public static List<HandlerKey> from(final RequestMapping requestMapping) {
+        String url = requestMapping.value();
+        List<RequestMethod> requestMethods = Arrays.stream(requestMapping.method())
+                .collect(Collectors.toList());
+
+        List<HandlerKey> handlerKeys = new ArrayList<>();
+        for (RequestMethod requestMethod : requestMethods) {
+            HandlerKey handlerKey = new HandlerKey(url, requestMethod);
+            handlerKeys.add(handlerKey);
+        }
+
+        return handlerKeys;
+    }
+
     @Override
     public String toString() {
         return "HandlerKey{" +
@@ -24,8 +51,12 @@ public String toString() {
 
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (!(o instanceof HandlerKey)) return false;
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof HandlerKey)) {
+            return false;
+        }
         HandlerKey that = (HandlerKey) o;
         return Objects.equals(url, that.url) && requestMethod == that.requestMethod;
     }

mvc/src/main/java/nextstep/mvc/controller/tobe/exception/ControllerNotFoundException.java

@@ -0,0 +1,8 @@
+package nextstep.mvc.controller.tobe.exception;
+
+public class ControllerNotFoundException extends RuntimeException {
+
+    public ControllerNotFoundException() {
+        super("요청에 대한 적절한 컨트롤러를 찾을 수 없습니다.");
+    }
+}

mvc/src/main/java/nextstep/mvc/view/JspView.java

@@ -2,29 +2,34 @@
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Map;
-
 public class JspView implements View {
 
-    private static final Logger log = LoggerFactory.getLogger(JspView.class);
-
     public static final String REDIRECT_PREFIX = "redirect:";
+    private static final Logger log = LoggerFactory.getLogger(JspView.class);
+    private final String viewName;
 
     public JspView(final String viewName) {
+        this.viewName = viewName;
     }
 
     @Override
-    public void render(final Map<String, ?> model, final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        // todo
+    public void render(final Map<String, ?> model, 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);
 
         model.keySet().forEach(key -> {
             log.debug("attribute name : {}, value : {}", key, model.get(key));
             request.setAttribute(key, model.get(key));
         });
-
-        // todo
     }
 }