Simplify code following DeferredResult change for RC1

src/main/java/org/springframework/samples/async/chat/ChatController.java

@@ -7,70 +7,56 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
-import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.context.request.async.DeferredResult;
 
 @Controller
-@RequestMapping("/mvc/chat/{topic}/{user}")
+@RequestMapping("/mvc/chat")
 public class ChatController {
 
-	private final Map<String, ChatParticipant> chatParticipants = new ConcurrentHashMap<String, ChatParticipant>();
-
 	private final ChatRepository chatRepository;
 
+	private final Map<DeferredResult<List<String>>, Integer> chatRequests =
+			new ConcurrentHashMap<DeferredResult<List<String>>, Integer>();
+
+
 	@Autowired
 	public ChatController(ChatRepository chatRepository) {
 		this.chatRepository = chatRepository;
 	}
 
-	/**
-	 * Return chat messages immediately or hold the response till new chat messages
-	 * become available.
-	 */
-	@RequestMapping(method=RequestMethod.GET, produces="application/json")
+	@RequestMapping(method=RequestMethod.GET)
 	@ResponseBody
-	public Object getMessages(@PathVariable String topic, @PathVariable String user, @RequestParam int messageIndex) {
-		ChatParticipant participant = getChatParticipant(topic, user);
-		DeferredResult<List<String>> deferredResult = new DeferredResult<List<String>>(null, Collections.<String>emptyList());
-		List<String> messages = participant.getMessages(deferredResult, messageIndex);
-		return messages.isEmpty() ? deferredResult : messages;
-	}
+	public DeferredResult<List<String>> getMessages(@RequestParam int messageIndex) {
+
+		DeferredResult<List<String>> result = new DeferredResult<List<String>>(null, Collections.emptyList());
+		this.chatRequests.put(result, messageIndex);
 
-	private ChatParticipant getChatParticipant(String topic, String user) {
-		String key = topic + ":" + user;
-		ChatParticipant participant = this.chatParticipants.get(key);
-		if (participant == null) {
-			participant = new ChatParticipant(topic, this.chatRepository);
-			this.chatParticipants.put(key, participant);
+		List<String> messages = this.chatRepository.getMessages(messageIndex);
+		if (!messages.isEmpty()) {
+			this.chatRequests.remove(result);
+			result.setResult(messages);
 		}
-		return participant;
+
+		return result;
 	}
 
-	/**
-	 * Post a message to participants in the chat.
-	 */
 	@RequestMapping(method=RequestMethod.POST)
 	@ResponseBody
-	public void postMessage(@PathVariable String topic, @PathVariable String user, @RequestParam String message) {
-		String chatMessage = "[" + user + "] " + message;
-		this.chatRepository.addMessage(topic, chatMessage);
-		for (ChatParticipant participant : this.chatParticipants.values()) {
-			participant.handleMessage(topic, chatMessage);
-		}
+	public void postMessage(@RequestParam String message) {
+		this.chatRepository.addMessage(message);
+		updateChatRequests();
 	}
 
-	/**
-	 * End participation in a chat.
-	 */
-	@RequestMapping(method=RequestMethod.DELETE)
-	@ResponseBody
-	public void removeParticipant(@PathVariable String topic, @PathVariable String user) {
-		ChatParticipant participant = this.chatParticipants.remove(topic + ":" + user);
-		participant.exitChat();
+	private void updateChatRequests() {
+		for (DeferredResult<List<String>> result : this.chatRequests.keySet()) {
+			Integer index = this.chatRequests.remove(result);
+			List<String> messages = this.chatRepository.getMessages(index);
+			result.setResult(messages);
+		}
 	}
 
 }

src/main/java/org/springframework/samples/async/chat/ChatRepository.java

@@ -18,13 +18,10 @@
 
 import java.util.List;
 
-/**
- * A repository for persisting chat messages.
- */
 public interface ChatRepository {
 
-	List<String> getMessages(String topic, int messageIndex);
+	List<String> getMessages(int messageIndex);
 
-	void addMessage(String topic, String message);
+	void addMessage(String message);
 
 }

src/main/java/org/springframework/samples/async/chat/InMemoryChatRepository.java

@@ -18,40 +18,26 @@
 
 import java.util.Collections;
 import java.util.List;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 import org.springframework.stereotype.Repository;
 import org.springframework.util.Assert;
 
-/**
- * Stores chat messages in-memory.
- */
 @Repository
 public class InMemoryChatRepository implements ChatRepository {
 
-	private final ConcurrentHashMap<String, List<String>> messages = new ConcurrentHashMap<String, List<String>>();
+	private final List<String> messages = new CopyOnWriteArrayList<String>();
 
-	public List<String> getMessages(String topic, int messageIndex) {
-		List<String> chatMessages = this.messages.get(topic);
-		if (chatMessages == null) {
+	public List<String> getMessages(int index) {
+		if (this.messages.isEmpty()) {
 			return Collections.<String> emptyList();
 		}
-		else {
-			Assert.isTrue((messageIndex >= 0) && (messageIndex <= chatMessages.size()), "Invalid messageIndex");
-			return chatMessages.subList(messageIndex, chatMessages.size());
-		}
+		Assert.isTrue((index >= 0) && (index <= this.messages.size()), "Invalid message index");
+		return this.messages.subList(index, this.messages.size());
 	}
 
-	public void addMessage(String topic, String message) {
-		initChat(topic);
-		this.messages.get(topic).add(message);
-	}
-
-	private void initChat(String topic) {
-		if (!this.messages.containsKey(topic)) {
-			this.messages.putIfAbsent(topic, new CopyOnWriteArrayList<String>());
-		}
+	public void addMessage(String message) {
+		this.messages.add(message);
 	}
 
 }

src/main/java/org/springframework/samples/async/config/WebMvcConfig.java

@@ -1,8 +1,12 @@
 package org.springframework.samples.async.config;
 
+import java.util.List;
+
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter;
 import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.config.annotation.AsyncSupportConfigurer;
@@ -24,6 +28,11 @@ public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
 		configurer.setDefaultTimeout(30*1000L);
 	}
 
+	@Override
+	protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
+		converters.add(new MappingJacksonHttpMessageConverter());
+	}
+
 	public void addViewControllers(ViewControllerRegistry registry) {
 		registry.addViewController("/").setViewName("chat");
 	}

src/main/webapp/WEB-INF/templates/chat.html

@@ -7,7 +7,7 @@
 <body>
 	<h1>Chat</h1>
 
-	<form id="joinChatForm" th:action="@{/mvc/chat/general}" data-bind="visible: activePollingXhr() == null">
+	<form id="joinChatForm" th:action="@{/mvc/chat}" data-bind="visible: activePollingXhr() == null">
 		<p>
 			<label for="user">User: </label>
 			<input id="user" name="user" type="text" data-bind="value: userName"/>
@@ -16,7 +16,7 @@ <h1>Chat</h1>
 		</p>
 	</form>
 
-	<form id="leaveChatForm" th:action="@{/mvc/chat/general}" data-bind="visible: activePollingXhr() != null">
+	<form id="leaveChatForm" th:action="@{/mvc/chat}" data-bind="visible: activePollingXhr() != null">
 		<p>
 			You're chatting as <strong data-bind="text: userName"></strong>
 			<button id="leave" type="submit" data-bind="click: leaveChat">Leave Chat</button>
@@ -27,7 +27,7 @@ <h1>Chat</h1>
 		<textarea rows="15" cols="60" readonly="readonly" data-bind="text: chatContent"></textarea>
 	</div>
 
-	<form id="postMessageForm" th:action="@{/mvc/chat/general}" data-bind="visible: activePollingXhr() != null">
+	<form id="postMessageForm" th:action="@{/mvc/chat}" data-bind="visible: activePollingXhr() != null">
 		<p>
 			<input id="message" name="message" type="text" data-bind="value: message" />
 			<button id="post" type="submit" data-bind="click: postMessage">Post</button>

src/main/webapp/resources/js/chat.js

@@ -24,7 +24,7 @@ $(document).ready(function() {
 				return;
 			}
 			var form = $("#joinChatForm");
-			that.activePollingXhr($.ajax({url : getChatUrl(form), type : "GET", data : form.serialize(),
+			that.activePollingXhr($.ajax({url : form.attr("action"), type : "GET", data : form.serialize(),
 				success : function(messages) {
 					for ( var i = 0; i < messages.length; i++) {
 						that.chatContent(that.chatContent() + messages[i] + "\n");
@@ -42,14 +42,11 @@ $(document).ready(function() {
 			$('#message').focus();
 		}
 
-		function getChatUrl(form) {
-			return form.attr("action") + "/" + that.userName();
-		}
-
 		that.postMessage = function() {
 			if (that.message().trim() != '') {
 				var form = $("#postMessageForm");
-				$.ajax({url : getChatUrl(form), type : "POST", data : form.serialize(),
+				$.ajax({url : form.attr("action"), type : "POST",
+				  data : "message=[" + that.userName() + "] " + $("#postMessageForm input[name=message]").val(),
 					error : function(xhr) {
 						console.error("Error posting chat message: status=" + xhr.status + ", statusText=" + xhr.statusText);
 					}
@@ -61,12 +58,6 @@ $(document).ready(function() {
 		that.leaveChat = function() {
 			that.activePollingXhr(null);
 			resetUI();
-			var form = $("#leaveChatForm");
-			$.ajax({url : getChatUrl(form), type : 'DELETE',
-				error : function(xhr) {
-					console.error("Error while leaving chat: status=" + xhr.status + ", statusText=" + xhr.statusText);
-				}
-			});
 			this.userName('');
 		}