Add Spring WebSocket example

spring-mvc-java/pom.xml

@@ -17,6 +17,28 @@
             <artifactId>spring-webmvc</artifactId>
             <version>${org.springframework.version}</version>
         </dependency>
+        <dependency>
+		    <groupId>org.springframework</groupId>
+		    <artifactId>spring-websocket</artifactId>
+		    <version>${org.springframework.version}</version>
+		</dependency>
+		<dependency>
+		    <groupId>org.springframework</groupId>
+		    <artifactId>spring-messaging</artifactId>
+		    <version>${org.springframework.version}</version>
+		</dependency>
+		<!-- Jackson -->
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-core</artifactId>
+			<version>2.7.3</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>2.7.3</version>
+		</dependency>
+		
         <!-- web -->
         <dependency>
             <groupId>javax.servlet</groupId>

spring-mvc-java/src/main/java/com/baeldung/model/Message.java

@@ -0,0 +1,15 @@
+package com.baeldung.model;
+
+public class Message {
+
+	private String from;
+	private String text;
+
+	public String getText() {
+		return text;
+	}
+
+	public String getFrom() {
+		return from;
+	}
+}

spring-mvc-java/src/main/java/com/baeldung/model/OutputMessage.java

@@ -0,0 +1,27 @@
+package com.baeldung.model;
+
+public class OutputMessage {
+
+	private String from;
+	private String text;
+	private String time;
+
+	public OutputMessage(final String from, final String text, final String time) {
+
+		this.from = from;
+		this.text = text;
+		this.time = time;
+	}
+
+	public String getText() {
+		return text;
+	}
+
+	public String getTime() {
+		return time;
+	}
+
+	public String getFrom() {
+		return from;
+	}
+}

spring-mvc-java/src/main/java/com/baeldung/spring/web/config/MainWebAppInitializer.java

@@ -14,7 +14,7 @@ import org.springframework.web.servlet.DispatcherServlet;
 
 public class MainWebAppInitializer implements WebApplicationInitializer {
 
-    private static final String TMP_FOLDER = "C:/Users/ivan/Desktop/tmp";
+    private static final String TMP_FOLDER = "/tmp";
     private static final int MAX_UPLOAD_SIZE = 5 * 1024 * 1024; // 5 MB
 
     /**

spring-mvc-java/src/main/java/com/baeldung/spring/web/config/WebSocketConfig.java

@@ -0,0 +1,24 @@
+package com.baeldung.spring.web.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.simp.config.MessageBrokerRegistry;
+import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
+import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
+import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
+
+@Configuration
+@EnableWebSocketMessageBroker
+public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
+
+	@Override
+	public void configureMessageBroker(final MessageBrokerRegistry config) {
+		config.enableSimpleBroker("/topic");
+		config.setApplicationDestinationPrefixes("/app");
+	}
+
+	@Override
+	public void registerStompEndpoints(final StompEndpointRegistry registry) {
+		registry.addEndpoint("/chat").withSockJS();
+	}
+
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/ChatController.java

@@ -0,0 +1,23 @@
+package com.baeldung.web.controller;
+
+import com.baeldung.model.Message;
+import com.baeldung.model.OutputMessage;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.handler.annotation.SendTo;
+import org.springframework.stereotype.Controller;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+@Controller
+public class ChatController {
+
+    @MessageMapping("/chat")
+    @SendTo("/topic/messages")
+    public OutputMessage send(final Message message) throws Exception {
+
+        final String time = new SimpleDateFormat("HH:mm").format(new Date());
+        return new OutputMessage(message.getFrom(), message.getText(), time);
+    }
+
+}

spring-mvc-java/src/main/webapp/resources/chat.html

@@ -0,0 +1,88 @@
+<html>
+	<head>
+	    <title>Chat WebSocket</title>
+	    
+	    <script src="./js/sockjs-0.3.4.js"></script>
+	    <script src="./js/stomp.js"></script>
+	    
+	    <script type="text/javascript">
+	    
+	        var stompClient = null;
+	        
+	        function setConnected(connected) {
+	        	
+	            document.getElementById('connect').disabled = connected;
+	            document.getElementById('disconnect').disabled = !connected;
+	            document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';
+	            document.getElementById('response').innerHTML = '';
+	        }
+	        
+	        function connect() {
+	        	
+	            var socket = new SockJS('/spring-mvc-java/chat');
+	            stompClient = Stomp.over(socket);  
+	            
+	            stompClient.connect({}, function(frame) {
+	                
+	            	setConnected(true);
+	                console.log('Connected: ' + frame);
+	                stompClient.subscribe('/topic/messages', function(messageOutput) {
+	                	
+	                    showMessageOutput(JSON.parse(messageOutput.body));
+	                });
+	            });
+	        }
+	        
+	        function disconnect() {
+	        	
+	            if(stompClient != null) {
+	                stompClient.disconnect();
+	            }
+	            
+	            setConnected(false);
+	            console.log("Disconnected");
+	        }
+	        
+	        function sendMessage() {
+	        	
+	        	var from = document.getElementById('from').value;
+	            var text = document.getElementById('text').value;
+	            stompClient.send("/app/chat", {}, JSON.stringify({'from':from, 'text':text}));
+	        }
+	        
+	        function showMessageOutput(messageOutput) {
+	        	
+	            var response = document.getElementById('response');
+	            var p = document.createElement('p');
+	            p.style.wordWrap = 'break-word';
+	            p.appendChild(document.createTextNode(messageOutput.from + ": " + messageOutput.text + " (" + messageOutput.time + ")"));
+	            response.appendChild(p);
+	        }
+	        
+	    </script>
+	    
+	</head>
+	
+	<body onload="disconnect()">
+
+		<div>
+		
+		
+			<div>
+				<input type="text" id="from" placeholder="Choose a nickname"/>
+			</div>
+			<br />
+		    <div>
+		        <button id="connect" onclick="connect();">Connect</button>
+		        <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
+		    </div>
+		    <br />
+		    <div id="conversationDiv">
+		        <input type="text" id="text" placeholder="Write a message..."/>
+		        <button id="sendMessage" onclick="sendMessage();">Send</button>
+		        <p id="response"></p>
+		    </div>
+		</div>
+
+	</body>
+</html>