feat: 어노테이션 기반 mvc 프레임워크 구현

mvc/src/main/java/web/org/springframework/web/bind/annotation/RequestMethod.java

@@ -1,5 +1,27 @@
 package web.org.springframework.web.bind.annotation;
 
+import java.util.Arrays;
+
 public enum RequestMethod {
-    GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE
+    GET("GET"),
+    HEAD("HEAD"),
+    POST("POST"),
+    PUT("PUT"),
+    PATCH("PATCH"),
+    DELETE("DELETE"),
+    OPTIONS("OPTIONS"),
+    TRACE("TRACE");
+
+    private final String methodName;
+
+    RequestMethod(String methodName) {
+        this.methodName = methodName;
+    }
+
+    public static RequestMethod from(String methodName) {
+        return Arrays.stream(values())
+                .filter(method -> method.methodName.equals(methodName))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 메소드입니다"));
+    }
 }

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/AnnotationHandlerMapping.java

@@ -1,11 +1,18 @@
 package webmvc.org.springframework.web.servlet.mvc.tobe;
 
+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 java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
 public class AnnotationHandlerMapping {
 
@@ -19,11 +26,29 @@ public AnnotationHandlerMapping(final Object... basePackage) {
         this.handlerExecutions = new HashMap<>();
     }
 
-    public void initialize() {
+    public void initialize() throws NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
+        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 = controller.getDeclaredConstructor().newInstance();
+                        HandlerKey handlerKey = new HandlerKey(url, requestMethod);
+                        HandlerExecution handlerExecution = new HandlerExecution(instance, method);
+                        handlerExecutions.put(handlerKey, handlerExecution);
+                    }
+                }
+            }
+        }
         log.info("Initialized AnnotationHandlerMapping!");
     }
 
     public Object getHandler(final HttpServletRequest request) {
-        return null;
+        HandlerKey handlerKey = new HandlerKey(request.getRequestURI(), RequestMethod.from(request.getMethod()));
+        return handlerExecutions.get(handlerKey);
     }
 }

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/HandlerExecution.java

@@ -4,9 +4,18 @@
 import jakarta.servlet.http.HttpServletResponse;
 import webmvc.org.springframework.web.servlet.ModelAndView;
 
+import java.lang.reflect.Method;
+
 public class HandlerExecution {
+    private final Object controller;
+    private final Method method;
+
+    public HandlerExecution(Object controller, Method method) {
+        this.controller = controller;
+        this.method = method;
+    }
 
     public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        return null;
+        return (ModelAndView) method.invoke(controller, request, response);
     }
 }

mvc/src/test/java/webmvc/org/springframework/web/servlet/mvc/tobe/AnnotationHandlerMappingTest.java

@@ -5,6 +5,8 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import java.lang.reflect.InvocationTargetException;
+
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -14,7 +16,7 @@ class AnnotationHandlerMappingTest {
     private AnnotationHandlerMapping handlerMapping;
 
     @BeforeEach
-    void setUp() {
+    void setUp() throws InvocationTargetException, NoSuchMethodException, InstantiationException, IllegalAccessException {
         handlerMapping = new AnnotationHandlerMapping("samples");
         handlerMapping.initialize();
     }