java reflection - 디스패쳐 필터 생성- 메소드 검색- 어노테이션으로 검색- 주소 매핑

reflect/src/main/java/com/example/reflect/anno/RequestMapping.java

@@ -0,0 +1,12 @@
+package com.example.reflect.anno;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.METHOD}) // 어노테이션 동작위치
+@Retention(RetentionPolicy.RUNTIME) // 어노테이션 동작시기
+public @interface RequestMapping {
+    String value();
+}

reflect/src/main/java/com/example/reflect/controller/UserController.java

@@ -1,11 +1,30 @@
 package com.example.reflect.controller;
 
+import com.example.reflect.anno.RequestMapping;
+
 public class UserController {
 
-    public void join(){
+    @RequestMapping("/join")
+    public String join(){
         System.out.println("join() 함수 호출");
+        return "/";
     }
-    public void login(){
+
+    @RequestMapping("/login")
+    public String login(){
         System.out.println("login()함수 호출");
+        return "/";
+    }
+
+    @RequestMapping("/user")
+    public String user(){
+        System.out.println("user()함수 호출");
+        return "/";
+    }
+
+    @RequestMapping("/hello")
+    public String hello(){
+        System.out.println("hello()함수 호출");
+        return "/";
     }
 }

reflect/src/main/java/com/example/reflect/filter/Dispatcher.java

@@ -1,11 +1,15 @@
 package com.example.reflect.filter;
 
+import com.example.reflect.anno.RequestMapping;
 import com.example.reflect.controller.UserController;
 
 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 
 public class Dispatcher implements Filter {
 
@@ -21,12 +25,46 @@ public class Dispatcher implements Filter {
 //        System.out.println("전체주소 : " + request.getRequestURL());
 
         String endPoint = request.getRequestURI().replaceAll(request.getContextPath(), "");
-
+        System.out.println("엔드포인트 : " + endPoint);
         UserController userController = new UserController();
-        if(endPoint.equals("/join")){
-            userController.join();
-        }else if(endPoint.equals("/login")){
-            userController.login();
+//        if(endPoint.equals("/join")){
+//            userController.join();
+//        }else if(endPoint.equals("/login")){
+//            userController.login();
+//        }
+//
+//        Method[] methods = userController.getClass().getMethods(); // 모든 메소드만( 상속 된 메소드 포함)
+        // 리플렉션 -> 메소드를 런타임 시점에서 찾아내서 실행
+        Method[] methods = userController.getClass().getDeclaredMethods(); // 그 파일의 메소드만
+//        for(Method method : methods) {
+////            System.out.println(method.getName());
+//            if(endPoint.equals("/"+method.getName())) {
+//                try {
+//                    method.invoke(userController);
+//                } catch (Exception e) {
+//                    e.printStackTrace();
+//                }
+//            }
+//        }
+
+        for (Method method : methods) { // 메소드 갯수만큼 반복
+            Annotation annotation = method.getDeclaredAnnotation(RequestMapping.class);
+            RequestMapping requestMapping = (RequestMapping) annotation;
+            System.out.println(requestMapping.value());
+
+            if(requestMapping.value().equals(endPoint)) {
+                try {
+                    String path = (String) method.invoke(userController);
+
+                    RequestDispatcher dis = request.getRequestDispatcher(path);
+                    // 내부에서 실행하기 때문에 필터 안탐
+                    dis.forward(request, response);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                } finally {
+                    break;
+                }
+            }
         }
     }
 }