feat: AnnotationHandlerMapping 구현

README.md

@@ -3,4 +3,4 @@
 ---
 
 ## 1. @MVC 프레임워크 구현하기
-- [ ] AnnotationHandlerMapping 구현  
+- [x] AnnotationHandlerMapping 구현  

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

@@ -1,11 +1,20 @@
 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.Method;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public class AnnotationHandlerMapping {
 
@@ -21,9 +30,43 @@ public AnnotationHandlerMapping(final Object... basePackage) {
 
     public void initialize() {
         log.info("Initialized AnnotationHandlerMapping!");
+        Reflections reflections = new Reflections(basePackage);
+        Set<Class<?>> controllers = reflections.getTypesAnnotatedWith(Controller.class);
+        List<Method> requestMappingMethods = mapRequestMappingMethods(controllers);
+
+        putHandlerExecutions(requestMappingMethods);
+    }
+
+    private List<Method> mapRequestMappingMethods(Set<Class<?>> controllers) {
+        return controllers.stream()
+                .map(Class::getDeclaredMethods).flatMap(Stream::of)
+                .filter(method -> method.isAnnotationPresent(RequestMapping.class))
+                .collect(Collectors.toList());
+    }
+
+    private void putHandlerExecutions(List<Method> requestMappingMethods) {
+        requestMappingMethods.forEach(method -> {
+            Object controller = createControllerInstance(method);
+            RequestMapping annotation = method.getAnnotation(RequestMapping.class);
+            String path = annotation.value();
+            RequestMethod[] requestMethods = annotation.method();
+            RequestMethod requestMethod = RequestMethod.valueOf(requestMethods[0].name());
+            handlerExecutions.put(new HandlerKey(path, requestMethod), new HandlerExecution(controller, method));
+        });
+    }
+
+    private Object createControllerInstance(Method method) {
+        try {
+            return method.getDeclaringClass().newInstance();
+        } catch (InstantiationException | IllegalAccessException e) {
+            throw new IllegalArgumentException(e);
+        }
     }
 
     public Object getHandler(final HttpServletRequest request) {
-        return null;
+        RequestMethod requestMethod = RequestMethod.valueOf(request.getMethod());
+        HandlerKey handlerKey = new HandlerKey(request.getRequestURI(), requestMethod);
+
+        return handlerExecutions.get(handlerKey);
     }
 }

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

@@ -4,9 +4,19 @@
 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);
     }
 }