feat : AnnotationHandlerMapping 구현

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

@@ -1,29 +1,66 @@
 package webmvc.org.springframework.web.servlet.mvc.tobe;
 
+import context.org.springframework.stereotype.Controller;
 import jakarta.servlet.http.HttpServletRequest;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
+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;
 
 public class AnnotationHandlerMapping {
 
-    private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
+  private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
 
-    private final Object[] basePackage;
-    private final Map<HandlerKey, HandlerExecution> handlerExecutions;
+  private final Object[] basePackages;
+  private final Map<HandlerKey, HandlerExecution> handlerExecutions;
 
-    public AnnotationHandlerMapping(final Object... basePackage) {
-        this.basePackage = basePackage;
-        this.handlerExecutions = new HashMap<>();
-    }
+  public AnnotationHandlerMapping(final Object... basePackages) {
+    this.basePackages = basePackages;
+    this.handlerExecutions = new HashMap<>();
+  }
+
+  public void initialize()
+      throws NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
+    log.info("Initialized AnnotationHandlerMapping!");
+
+    final Reflections reflections = new Reflections(basePackages);
 
-    public void initialize() {
-        log.info("Initialized AnnotationHandlerMapping!");
+    final Set<Class<?>> controllerAnnotationClasses =
+        reflections.getTypesAnnotatedWith(Controller.class);
+
+    for (Class<?> controllerAnnotationClass : controllerAnnotationClasses) {
+      final Object instance = controllerAnnotationClass.getDeclaredConstructor().newInstance();
+      final Method[] methods = controllerAnnotationClass.getDeclaredMethods();
+
+      Arrays.stream(methods)
+          .filter(method -> method.isAnnotationPresent(RequestMapping.class))
+          .forEach(method -> putHandlerExecutions(method, instance));
     }
+  }
+
+  private void putHandlerExecutions(final Method method, final Object target) {
+    final RequestMapping requestMapping = method.getAnnotation(RequestMapping.class);
+
+    for (final RequestMethod requestMethod : requestMapping.method()) {
+      final HandlerKey handlerKey = new HandlerKey(requestMapping.value(), requestMethod);
 
-    public Object getHandler(final HttpServletRequest request) {
-        return null;
+      handlerExecutions.put(handlerKey, new HandlerExecution(method, target));
     }
+  }
+
+  public Object getHandler(final HttpServletRequest request) {
+    final String requestURI = request.getRequestURI();
+    final String method = request.getMethod();
+
+    final HandlerKey handlerKey = new HandlerKey(requestURI, RequestMethod.find(method));
+
+    return handlerExecutions.get(handlerKey);
+  }
 }

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

@@ -2,11 +2,24 @@
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import webmvc.org.springframework.web.servlet.ModelAndView;
 
 public class HandlerExecution {
 
-    public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        return null;
-    }
+  private final Method method;
+  private final Object target;
+
+  public HandlerExecution(final Method method, final Object target) {
+    this.method = method;
+    this.target = target;
+  }
+
+  public ModelAndView handle(
+      final HttpServletRequest request,
+      final HttpServletResponse response
+  ) throws InvocationTargetException, IllegalAccessException {
+    return (ModelAndView) method.invoke(target, request, response);
+  }
 }

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

@@ -2,6 +2,7 @@
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.lang.reflect.InvocationTargetException;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -14,7 +15,8 @@ class AnnotationHandlerMappingTest {
     private AnnotationHandlerMapping handlerMapping;
 
     @BeforeEach
-    void setUp() {
+    void setUp()
+        throws InvocationTargetException, NoSuchMethodException, InstantiationException, IllegalAccessException {
         handlerMapping = new AnnotationHandlerMapping("samples");
         handlerMapping.initialize();
     }