Siyoon/step5

src/main/java/core/mvc/Controller.java

@@ -1,8 +1,10 @@
 package core.mvc;
 
+import core.mvc.modelandview.ModelAndView;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 public interface Controller {
-    String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception;
+    ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception;
 }

src/main/java/core/mvc/DispatcherServlet.java

@@ -1,56 +1,40 @@
 package core.mvc;
 
-import java.io.IOException;
+import core.mvc.modelandview.ModelAndView;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 @WebServlet(name = "dispatcher", urlPatterns = "/", loadOnStartup = 1)
 public class DispatcherServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;
     private static final Logger logger = LoggerFactory.getLogger(DispatcherServlet.class);
-    private static final String DEFAULT_REDIRECT_PREFIX = "redirect:";
 
     private RequestMapping rm;
 
     @Override
-    public void init() throws ServletException {
+    public void init() {
         rm = new RequestMapping();
         rm.initMapping();
     }
 
     @Override
-    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException {
         String requestUri = req.getRequestURI();
         logger.debug("Method : {}, Request URI : {}", req.getMethod(), requestUri);
 
         Controller controller = rm.findController(requestUri);
         try {
-            String viewName = controller.execute(req, resp);
-            if (viewName != null) {
-                move(viewName, req, resp);
-            }
+            ModelAndView modelAndView = controller.execute(req, resp);
+            modelAndView.render(req, resp);
         } catch (Throwable e) {
             logger.error("Exception : {}", e);
             throw new ServletException(e.getMessage());
         }
     }
-
-    private void move(String viewName, HttpServletRequest req, HttpServletResponse resp)
-            throws ServletException, IOException {
-        if (viewName.startsWith(DEFAULT_REDIRECT_PREFIX)) {
-            resp.sendRedirect(viewName.substring(DEFAULT_REDIRECT_PREFIX.length()));
-            return;
-        }
-
-        RequestDispatcher rd = req.getRequestDispatcher(viewName);
-        rd.forward(req, resp);
-    }
 }

src/main/java/core/mvc/ForwardController.java

@@ -1,5 +1,7 @@
 package core.mvc;
 
+import core.mvc.modelandview.ModelAndView;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -14,7 +16,8 @@ public ForwardController(String forwardUrl) {
     }
 
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
-        return forwardUrl;
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+        return ModelAndView.builder()
+                .jspView(forwardUrl);
     }
 }

src/main/java/core/mvc/modelandview/ModelAndView.java

@@ -0,0 +1,52 @@
+package core.mvc.modelandview;
+
+import core.mvc.view.JsonView;
+import core.mvc.view.JspView;
+import core.mvc.view.View;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ModelAndView {
+    private final Map<String, Object> model;
+    private final View view;
+
+    private ModelAndView(Map<String, Object> model, View view) {
+        this.model = model;
+        this.view = view;
+    }
+
+    public void render(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+        view.render(req, resp, model);
+    }
+
+    public static ModelAndViewBuilder builder() {
+        return new ModelAndViewBuilder();
+    }
+
+    public static class ModelAndViewBuilder {
+        private final Map<String, Object> model;
+        private View view;
+
+        public ModelAndViewBuilder() {
+            this.model = new HashMap<>();
+        }
+
+        public ModelAndViewBuilder addAttribute(String key, Object value) {
+            model.put(key, value);
+            return this;
+        }
+
+        public ModelAndView jspView(String viewName) {
+            view = new JspView(viewName);
+            return new ModelAndView(model, view);
+        }
+
+        public ModelAndView jsonView() {
+            view = new JsonView();
+            return new ModelAndView(model, view);
+        }
+    }
+}

src/main/java/core/mvc/view/JsonView.java

@@ -0,0 +1,29 @@
+package core.mvc.view;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.PrintWriter;
+import java.util.Enumeration;
+import java.util.Map;
+
+public class JsonView implements View {
+    @Override
+    public void render(HttpServletRequest req, HttpServletResponse resp, Map<String, Object> model) throws Exception {
+        ObjectMapper mapper = new ObjectMapper();
+        resp.setContentType("application/json;charset=UTF-8");
+        PrintWriter out = resp.getWriter();
+        out.print(mapper.writeValueAsString(model));
+    }
+
+    private Map<String, Object> createModel(HttpServletRequest req, Map<String, Object> model) {
+        final Enumeration<String> names = req.getAttributeNames();
+        while (names.hasMoreElements()) {
+            final String name = names.nextElement();
+            model.put(name, req.getAttribute(name));
+        }
+
+        return model;
+    }
+}

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

@@ -0,0 +1,35 @@
+package core.mvc.view;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.util.Map;
+
+public class JspView implements View {
+    private static final String DEFAULT_REDIRECT_PREFIX = "redirect:";
+
+    private final String url;
+
+    public JspView(String url) {
+        this.url = url;
+    }
+
+    @Override
+    public void render(HttpServletRequest req, HttpServletResponse resp, Map<String, Object> model) throws Exception {
+        model.forEach(req::setAttribute);
+        move(url, req, resp);
+    }
+
+    private void move(String viewName, HttpServletRequest req, HttpServletResponse resp)
+            throws ServletException, IOException {
+        if (viewName.startsWith(DEFAULT_REDIRECT_PREFIX)) {
+            resp.sendRedirect(viewName.substring(DEFAULT_REDIRECT_PREFIX.length()));
+            return;
+        }
+
+        RequestDispatcher rd = req.getRequestDispatcher(viewName);
+        rd.forward(req, resp);
+    }
+}

src/main/java/core/mvc/view/View.java

@@ -0,0 +1,9 @@
+package core.mvc.view;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.Map;
+
+public interface View {
+    void render(HttpServletRequest req, HttpServletResponse resp, Map<String, Object> model) throws Exception;
+}

src/main/java/next/controller/HomeController.java

@@ -1,16 +1,18 @@
 package next.controller;
 
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
 import core.mvc.Controller;
+import core.mvc.modelandview.ModelAndView;
 import next.dao.QuestionDao;
 
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
 public class HomeController implements Controller {
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
         QuestionDao questionDao = new QuestionDao();
-        req.setAttribute("questions", questionDao.findAll());
-        return "home.jsp";
+        return ModelAndView.builder()
+                .addAttribute("questions", questionDao.findAll())
+                .jspView("home.jsp");
     }
 }

src/main/java/next/controller/qna/AddAnswerController.java

@@ -1,34 +1,29 @@
 package next.controller.qna;
 
-import java.io.PrintWriter;
-
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-
 import core.mvc.Controller;
+import core.mvc.modelandview.ModelAndView;
 import next.dao.AnswerDao;
 import next.model.Answer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
 public class AddAnswerController implements Controller {
     private static final Logger log = LoggerFactory.getLogger(AddAnswerController.class);
 
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
         Answer answer = new Answer(req.getParameter("writer"), req.getParameter("contents"),
                 Long.parseLong(req.getParameter("questionId")));
         log.debug("answer : {}", answer);
 
         AnswerDao answerDao = new AnswerDao();
         Answer savedAnswer = answerDao.insert(answer);
-        ObjectMapper mapper = new ObjectMapper();
-        resp.setContentType("application/json;charset=UTF-8");
-        PrintWriter out = resp.getWriter();
-        out.print(mapper.writeValueAsString(savedAnswer));
-        return null;
+
+        return ModelAndView.builder()
+                .addAttribute("savedAnswer", savedAnswer)
+                .jsonView();
     }
 }

src/main/java/next/controller/qna/DeleteAnswerController.java

@@ -1,28 +1,21 @@
 package next.controller.qna;
 
-import java.io.PrintWriter;
+import core.mvc.Controller;
+import core.mvc.modelandview.ModelAndView;
+import next.dao.AnswerDao;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-
-import core.mvc.Controller;
-import next.dao.AnswerDao;
-import next.model.Result;
-
 public class DeleteAnswerController implements Controller {
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
         Long answerId = Long.parseLong(req.getParameter("answerId"));
         AnswerDao answerDao = new AnswerDao();
 
         answerDao.delete(answerId);
 
-        ObjectMapper mapper = new ObjectMapper();
-        resp.setContentType("application/json;charset=UTF-8");
-        PrintWriter out = resp.getWriter();
-        out.print(mapper.writeValueAsString(Result.ok()));
-        return null;
+        return ModelAndView.builder()
+                .jsonView();
     }
 }

src/main/java/next/controller/qna/ShowController.java

@@ -1,20 +1,23 @@
 package next.controller.qna;
 
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
 import core.mvc.Controller;
+import core.mvc.modelandview.ModelAndView;
 import next.dao.AnswerDao;
 import next.dao.QuestionDao;
 
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
 public class ShowController implements Controller {
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
-        Long questionId = Long.parseLong(req.getParameter("questionId"));
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+        long questionId = Long.parseLong(req.getParameter("questionId"));
         QuestionDao questionDao = new QuestionDao();
         AnswerDao answerDao = new AnswerDao();
-        req.setAttribute("question", questionDao.findById(questionId));
-        req.setAttribute("answers", answerDao.findAllByQuestionId(questionId));
-        return "/qna/show.jsp";
+
+        return ModelAndView.builder()
+                .addAttribute("question", questionDao.findById(questionId))
+                .addAttribute("answers", answerDao.findAllByQuestionId(questionId))
+                .jspView("/qna/show.jsp");
     }
 }

src/main/java/next/controller/user/CreateUserController.java

@@ -1,26 +1,27 @@
 package next.controller.user;
 
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import core.mvc.Controller;
+import core.mvc.modelandview.ModelAndView;
 import next.dao.UserDao;
 import next.model.User;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
 public class CreateUserController implements Controller {
     private static final Logger log = LoggerFactory.getLogger(CreateUserController.class);
 
     @Override
-    public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
+    public ModelAndView execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
         User user = new User(req.getParameter("userId"), req.getParameter("password"), req.getParameter("name"),
                 req.getParameter("email"));
         log.debug("User : {}", user);
 
         UserDao userDao = new UserDao();
         userDao.insert(user);
-        return "redirect:/";
+        return ModelAndView.builder()
+                .jspView("redirect:/");
     }
 }