Add Undertow WebSocket sample application

See gh-2028

spring-boot-samples/pom.xml

@@ -75,6 +75,7 @@
 		<module>spring-boot-sample-web-velocity</module>
 		<module>spring-boot-sample-websocket</module>
 		<module>spring-boot-sample-websocket-jetty</module>
+		<module>spring-boot-sample-websocket-undertow</module>
 		<module>spring-boot-sample-ws</module>
 		<module>spring-boot-sample-xml</module>
 	</modules>

spring-boot-samples/spring-boot-sample-websocket-undertow/pom.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<!-- Your own application should inherit from spring-boot-starter-parent -->
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-samples</artifactId>
+		<version>1.2.0.BUILD-SNAPSHOT</version>
+	</parent>
+	<artifactId>spring-boot-sample-websocket-undertow</artifactId>
+	<name>Spring Boot WebSocket Undertow Sample</name>
+	<description>Spring Boot WebSocket Undertow Sample</description>
+	<url>http://projects.spring.io/spring-boot/</url>
+	<organization>
+		<name>Pivotal Software, Inc.</name>
+		<url>http://www.spring.io</url>
+	</organization>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+		<java.version>1.7</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-websocket</artifactId>
+			<exclusions>
+				<exclusion>
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-starter-tomcat</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-undertow</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/client/GreetingService.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.client;
+
+public interface GreetingService {
+
+	String getGreeting();
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/client/SimpleClientWebSocketHandler.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.client;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+
+public class SimpleClientWebSocketHandler extends TextWebSocketHandler {
+
+	protected Log logger = LogFactory.getLog(SimpleClientWebSocketHandler.class);
+
+	private final GreetingService greetingService;
+
+	private final CountDownLatch latch;
+
+	private final AtomicReference<String> messagePayload;
+
+	@Autowired
+	public SimpleClientWebSocketHandler(GreetingService greetingService,
+			CountDownLatch latch, AtomicReference<String> message) {
+		this.greetingService = greetingService;
+		this.latch = latch;
+		this.messagePayload = message;
+	}
+
+	@Override
+	public void afterConnectionEstablished(WebSocketSession session) throws Exception {
+		TextMessage message = new TextMessage(this.greetingService.getGreeting());
+		session.sendMessage(message);
+	}
+
+	@Override
+	public void handleTextMessage(WebSocketSession session, TextMessage message)
+			throws Exception {
+		this.logger.info("Received: " + message + " (" + this.latch.getCount() + ")");
+		session.close();
+		this.messagePayload.set(message.getPayload());
+		this.latch.countDown();
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/client/SimpleGreetingService.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.client;
+
+public class SimpleGreetingService implements GreetingService {
+
+	@Override
+	public String getGreeting() {
+		return "Hello world!";
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/config/SampleUndertowWebSocketsApplication.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.config;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.context.web.SpringBootServletInitializer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.socket.WebSocketHandler;
+import org.springframework.web.socket.config.annotation.EnableWebSocket;
+import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
+import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
+import org.springframework.web.socket.handler.PerConnectionWebSocketHandler;
+import org.springframework.web.socket.server.standard.ServerEndpointExporter;
+
+import samples.websocket.client.GreetingService;
+import samples.websocket.client.SimpleGreetingService;
+import samples.websocket.echo.DefaultEchoService;
+import samples.websocket.echo.EchoService;
+import samples.websocket.echo.EchoWebSocketHandler;
+import samples.websocket.reverse.ReverseWebSocketEndpoint;
+import samples.websocket.snake.SnakeWebSocketHandler;
+
+@SpringBootApplication
+@EnableWebSocket
+public class SampleUndertowWebSocketsApplication extends SpringBootServletInitializer
+		implements WebSocketConfigurer {
+
+	@Override
+	public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
+		registry.addHandler(echoWebSocketHandler(), "/echo").withSockJS();
+		registry.addHandler(snakeWebSocketHandler(), "/snake").withSockJS();
+	}
+
+	@Override
+	protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+		return application.sources(SampleUndertowWebSocketsApplication.class);
+	}
+
+	@Bean
+	public EchoService echoService() {
+		return new DefaultEchoService("Did you say \"%s\"?");
+	}
+
+	@Bean
+	public GreetingService greetingService() {
+		return new SimpleGreetingService();
+	}
+
+	@Bean
+	public WebSocketHandler echoWebSocketHandler() {
+		return new EchoWebSocketHandler(echoService());
+	}
+
+	@Bean
+	public WebSocketHandler snakeWebSocketHandler() {
+		return new PerConnectionWebSocketHandler(SnakeWebSocketHandler.class);
+	}
+
+	@Bean
+	public ReverseWebSocketEndpoint reverseWebSocketEndpoint() {
+		return new ReverseWebSocketEndpoint();
+	}
+
+	@Bean
+	public ServerEndpointExporter serverEndpointExporter() {
+		return new ServerEndpointExporter();
+	}
+
+	public static void main(String[] args) {
+		SpringApplication.run(SampleUndertowWebSocketsApplication.class, args);
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/echo/DefaultEchoService.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.echo;
+
+public class DefaultEchoService implements EchoService {
+
+	private final String echoFormat;
+
+	public DefaultEchoService(String echoFormat) {
+		this.echoFormat = (echoFormat != null) ? echoFormat : "%s";
+	}
+
+	@Override
+	public String getMessage(String message) {
+		return String.format(this.echoFormat, message);
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/echo/EchoService.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.echo;
+
+public interface EchoService {
+
+	String getMessage(String message);
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/echo/EchoWebSocketHandler.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.echo;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketHandler;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+
+/**
+ * Echo messages by implementing a Spring {@link WebSocketHandler} abstraction.
+ */
+public class EchoWebSocketHandler extends TextWebSocketHandler {
+
+	private static Logger logger = LoggerFactory.getLogger(EchoWebSocketHandler.class);
+
+	private final EchoService echoService;
+
+	@Autowired
+	public EchoWebSocketHandler(EchoService echoService) {
+		this.echoService = echoService;
+	}
+
+	@Override
+	public void afterConnectionEstablished(WebSocketSession session) {
+		logger.debug("Opened new session in instance " + this);
+	}
+
+	@Override
+	public void handleTextMessage(WebSocketSession session, TextMessage message)
+			throws Exception {
+		String echoMessage = this.echoService.getMessage(message.getPayload());
+		logger.debug(echoMessage);
+		session.sendMessage(new TextMessage(echoMessage));
+	}
+
+	@Override
+	public void handleTransportError(WebSocketSession session, Throwable exception)
+			throws Exception {
+		session.close(CloseStatus.SERVER_ERROR);
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/reverse/ReverseWebSocketEndpoint.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.reverse;
+
+import java.io.IOException;
+
+import javax.websocket.OnMessage;
+import javax.websocket.Session;
+import javax.websocket.server.ServerEndpoint;
+
+@ServerEndpoint("/reverse")
+public class ReverseWebSocketEndpoint {
+
+	@OnMessage
+	public void handleMessage(Session session, String message) throws IOException {
+		session.getBasicRemote().sendText(
+				"Reversed: " + new StringBuilder(message).reverse());
+	}
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/Direction.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+public enum Direction {
+	NONE, NORTH, SOUTH, EAST, WEST
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/Location.java

@@ -0,0 +1,77 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+public class Location {
+
+	public int x;
+	public int y;
+	public static final int GRID_SIZE = 10;
+	public static final int PLAYFIELD_HEIGHT = 480;
+	public static final int PLAYFIELD_WIDTH = 640;
+
+	public Location(int x, int y) {
+		this.x = x;
+		this.y = y;
+	}
+
+	public Location getAdjacentLocation(Direction direction) {
+		switch (direction) {
+		case NORTH:
+			return new Location(this.x, this.y - Location.GRID_SIZE);
+		case SOUTH:
+			return new Location(this.x, this.y + Location.GRID_SIZE);
+		case EAST:
+			return new Location(this.x + Location.GRID_SIZE, this.y);
+		case WEST:
+			return new Location(this.x - Location.GRID_SIZE, this.y);
+		case NONE:
+			// fall through
+		default:
+			return this;
+		}
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+
+		Location location = (Location) o;
+
+		if (this.x != location.x) {
+			return false;
+		}
+		if (this.y != location.y) {
+			return false;
+		}
+
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = this.x;
+		result = 31 * result + this.y;
+		return result;
+	}
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/Snake.java

@@ -0,0 +1,139 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+import java.util.ArrayDeque;
+import java.util.Collection;
+import java.util.Deque;
+
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+
+public class Snake {
+
+	private static final int DEFAULT_LENGTH = 5;
+
+	private final int id;
+	private final WebSocketSession session;
+
+	private Direction direction;
+	private int length = DEFAULT_LENGTH;
+	private Location head;
+	private final Deque<Location> tail = new ArrayDeque<Location>();
+	private final String hexColor;
+
+	public Snake(int id, WebSocketSession session) {
+		this.id = id;
+		this.session = session;
+		this.hexColor = SnakeUtils.getRandomHexColor();
+		resetState();
+	}
+
+	private void resetState() {
+		this.direction = Direction.NONE;
+		this.head = SnakeUtils.getRandomLocation();
+		this.tail.clear();
+		this.length = DEFAULT_LENGTH;
+	}
+
+	private synchronized void kill() throws Exception {
+		resetState();
+		sendMessage("{'type': 'dead'}");
+	}
+
+	private synchronized void reward() throws Exception {
+		this.length++;
+		sendMessage("{'type': 'kill'}");
+	}
+
+	protected void sendMessage(String msg) throws Exception {
+		this.session.sendMessage(new TextMessage(msg));
+	}
+
+	public synchronized void update(Collection<Snake> snakes) throws Exception {
+		Location nextLocation = this.head.getAdjacentLocation(this.direction);
+		if (nextLocation.x >= SnakeUtils.PLAYFIELD_WIDTH) {
+			nextLocation.x = 0;
+		}
+		if (nextLocation.y >= SnakeUtils.PLAYFIELD_HEIGHT) {
+			nextLocation.y = 0;
+		}
+		if (nextLocation.x < 0) {
+			nextLocation.x = SnakeUtils.PLAYFIELD_WIDTH;
+		}
+		if (nextLocation.y < 0) {
+			nextLocation.y = SnakeUtils.PLAYFIELD_HEIGHT;
+		}
+		if (this.direction != Direction.NONE) {
+			this.tail.addFirst(this.head);
+			if (this.tail.size() > this.length) {
+				this.tail.removeLast();
+			}
+			this.head = nextLocation;
+		}
+
+		handleCollisions(snakes);
+	}
+
+	private void handleCollisions(Collection<Snake> snakes) throws Exception {
+		for (Snake snake : snakes) {
+			boolean headCollision = this.id != snake.id
+					&& snake.getHead().equals(this.head);
+			boolean tailCollision = snake.getTail().contains(this.head);
+			if (headCollision || tailCollision) {
+				kill();
+				if (this.id != snake.id) {
+					snake.reward();
+				}
+			}
+		}
+	}
+
+	public synchronized Location getHead() {
+		return this.head;
+	}
+
+	public synchronized Collection<Location> getTail() {
+		return this.tail;
+	}
+
+	public synchronized void setDirection(Direction direction) {
+		this.direction = direction;
+	}
+
+	public synchronized String getLocationsJson() {
+		StringBuilder sb = new StringBuilder();
+		sb.append(String.format("{x: %d, y: %d}", Integer.valueOf(this.head.x),
+				Integer.valueOf(this.head.y)));
+		for (Location location : this.tail) {
+			sb.append(',');
+			sb.append(String.format("{x: %d, y: %d}", Integer.valueOf(location.x),
+					Integer.valueOf(location.y)));
+		}
+		return String.format("{'id':%d,'body':[%s]}", Integer.valueOf(this.id),
+				sb.toString());
+	}
+
+	public int getId() {
+		return this.id;
+	}
+
+	public String getHexColor() {
+		return this.hexColor;
+	}
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/SnakeTimer.java

@@ -0,0 +1,109 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Sets up the timer for the multi-player snake game WebSocket example.
+ */
+public class SnakeTimer {
+
+	private static final Logger log = LoggerFactory.getLogger(SnakeTimer.class);
+
+	private static Timer gameTimer = null;
+
+	private static final long TICK_DELAY = 100;
+
+	private static final ConcurrentHashMap<Integer, Snake> snakes = new ConcurrentHashMap<Integer, Snake>();
+
+	public static synchronized void addSnake(Snake snake) {
+		if (snakes.size() == 0) {
+			startTimer();
+		}
+		snakes.put(Integer.valueOf(snake.getId()), snake);
+	}
+
+	public static Collection<Snake> getSnakes() {
+		return Collections.unmodifiableCollection(snakes.values());
+	}
+
+	public static synchronized void removeSnake(Snake snake) {
+		snakes.remove(Integer.valueOf(snake.getId()));
+		if (snakes.size() == 0) {
+			stopTimer();
+		}
+	}
+
+	public static void tick() throws Exception {
+		StringBuilder sb = new StringBuilder();
+		for (Iterator<Snake> iterator = SnakeTimer.getSnakes().iterator(); iterator
+				.hasNext();) {
+			Snake snake = iterator.next();
+			snake.update(SnakeTimer.getSnakes());
+			sb.append(snake.getLocationsJson());
+			if (iterator.hasNext()) {
+				sb.append(',');
+			}
+		}
+		broadcast(String.format("{'type': 'update', 'data' : [%s]}", sb.toString()));
+	}
+
+	public static void broadcast(String message) throws Exception {
+		Collection<Snake> snakes = new CopyOnWriteArrayList<>(SnakeTimer.getSnakes());
+		for (Snake snake : snakes) {
+			try {
+				snake.sendMessage(message);
+			}
+			catch (Throwable ex) {
+				// if Snake#sendMessage fails the client is removed
+				removeSnake(snake);
+			}
+		}
+	}
+
+	public static void startTimer() {
+		gameTimer = new Timer(SnakeTimer.class.getSimpleName() + " Timer");
+		gameTimer.scheduleAtFixedRate(new TimerTask() {
+			@Override
+			public void run() {
+				try {
+					tick();
+				}
+				catch (Throwable ex) {
+					log.error("Caught to prevent timer from shutting down", ex);
+				}
+			}
+		}, TICK_DELAY, TICK_DELAY);
+	}
+
+	public static void stopTimer() {
+		if (gameTimer != null) {
+			gameTimer.cancel();
+		}
+	}
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/SnakeUtils.java

@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+import java.awt.Color;
+import java.util.Random;
+
+public class SnakeUtils {
+
+	public static final int PLAYFIELD_WIDTH = 640;
+	public static final int PLAYFIELD_HEIGHT = 480;
+	public static final int GRID_SIZE = 10;
+
+	private static final Random random = new Random();
+
+	public static String getRandomHexColor() {
+		float hue = random.nextFloat();
+		// sat between 0.1 and 0.3
+		float saturation = (random.nextInt(2000) + 1000) / 10000f;
+		float luminance = 0.9f;
+		Color color = Color.getHSBColor(hue, saturation, luminance);
+		return '#' + Integer.toHexString((color.getRGB() & 0xffffff) | 0x1000000)
+				.substring(1);
+	}
+
+	public static Location getRandomLocation() {
+		int x = roundByGridSize(random.nextInt(PLAYFIELD_WIDTH));
+		int y = roundByGridSize(random.nextInt(PLAYFIELD_HEIGHT));
+		return new Location(x, y);
+	}
+
+	private static int roundByGridSize(int value) {
+		value = value + (GRID_SIZE / 2);
+		value = value / GRID_SIZE;
+		value = value * GRID_SIZE;
+		return value;
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/java/samples/websocket/snake/SnakeWebSocketHandler.java

@@ -0,0 +1,112 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+import java.awt.Color;
+import java.util.Iterator;
+import java.util.Random;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+
+public class SnakeWebSocketHandler extends TextWebSocketHandler {
+
+	public static final int PLAYFIELD_WIDTH = 640;
+	public static final int PLAYFIELD_HEIGHT = 480;
+	public static final int GRID_SIZE = 10;
+
+	private static final AtomicInteger snakeIds = new AtomicInteger(0);
+	private static final Random random = new Random();
+
+	private final int id;
+	private Snake snake;
+
+	public static String getRandomHexColor() {
+		float hue = random.nextFloat();
+		// sat between 0.1 and 0.3
+		float saturation = (random.nextInt(2000) + 1000) / 10000f;
+		float luminance = 0.9f;
+		Color color = Color.getHSBColor(hue, saturation, luminance);
+		return '#' + Integer.toHexString((color.getRGB() & 0xffffff) | 0x1000000)
+				.substring(1);
+	}
+
+	public static Location getRandomLocation() {
+		int x = roundByGridSize(random.nextInt(PLAYFIELD_WIDTH));
+		int y = roundByGridSize(random.nextInt(PLAYFIELD_HEIGHT));
+		return new Location(x, y);
+	}
+
+	private static int roundByGridSize(int value) {
+		value = value + (GRID_SIZE / 2);
+		value = value / GRID_SIZE;
+		value = value * GRID_SIZE;
+		return value;
+	}
+
+	public SnakeWebSocketHandler() {
+		this.id = snakeIds.getAndIncrement();
+	}
+
+	@Override
+	public void afterConnectionEstablished(WebSocketSession session) throws Exception {
+		this.snake = new Snake(this.id, session);
+		SnakeTimer.addSnake(this.snake);
+		StringBuilder sb = new StringBuilder();
+		for (Iterator<Snake> iterator = SnakeTimer.getSnakes().iterator(); iterator
+				.hasNext();) {
+			Snake snake = iterator.next();
+			sb.append(String.format("{id: %d, color: '%s'}",
+					Integer.valueOf(snake.getId()), snake.getHexColor()));
+			if (iterator.hasNext()) {
+				sb.append(',');
+			}
+		}
+		SnakeTimer
+				.broadcast(String.format("{'type': 'join','data':[%s]}", sb.toString()));
+	}
+
+	@Override
+	protected void handleTextMessage(WebSocketSession session, TextMessage message)
+			throws Exception {
+		String payload = message.getPayload();
+		if ("west".equals(payload)) {
+			this.snake.setDirection(Direction.WEST);
+		}
+		else if ("north".equals(payload)) {
+			this.snake.setDirection(Direction.NORTH);
+		}
+		else if ("east".equals(payload)) {
+			this.snake.setDirection(Direction.EAST);
+		}
+		else if ("south".equals(payload)) {
+			this.snake.setDirection(Direction.SOUTH);
+		}
+	}
+
+	@Override
+	public void afterConnectionClosed(WebSocketSession session, CloseStatus status)
+			throws Exception {
+		SnakeTimer.removeSnake(this.snake);
+		SnakeTimer.broadcast(String.format("{'type': 'leave', 'id': %d}",
+				Integer.valueOf(this.id)));
+	}
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/resources/static/echo.html

@@ -0,0 +1,133 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Apache Tomcat WebSocket Examples: Echo</title>
+    <style type="text/css">
+        #connect-container {
+            float: left;
+            width: 400px
+        }
+
+        #connect-container div {
+            padding: 5px;
+        }
+
+        #console-container {
+            float: left;
+            margin-left: 15px;
+            width: 400px;
+        }
+
+        #console {
+            border: 1px solid #CCCCCC;
+            border-right-color: #999999;
+            border-bottom-color: #999999;
+            height: 170px;
+            overflow-y: scroll;
+            padding: 5px;
+            width: 100%;
+        }
+
+        #console p {
+            padding: 0;
+            margin: 0;
+        }
+    </style>
+    <script src="https://cdn.jsdelivr.net/sockjs/0.3.4/sockjs.min.js"></script>
+    <script type="text/javascript">
+        var ws = null;
+
+        function setConnected(connected) {
+            document.getElementById('connect').disabled = connected;
+            document.getElementById('disconnect').disabled = !connected;
+            document.getElementById('echo').disabled = !connected;
+        }
+
+        function connect() {
+            var target = document.getElementById('target').value;
+            ws = new SockJS(target);
+            ws.onopen = function () {
+                setConnected(true);
+                log('Info: WebSocket connection opened.');
+            };
+            ws.onmessage = function (event) {
+                log('Received: ' + event.data);
+            };
+            ws.onclose = function () {
+                setConnected(false);
+                log('Info: WebSocket connection closed.');
+            };
+        }
+
+        function disconnect() {
+            if (ws != null) {
+                ws.close();
+                ws = null;
+            }
+            setConnected(false);
+        }
+
+        function echo() {
+            if (ws != null) {
+                var message = document.getElementById('message').value;
+                log('Sent: ' + message);
+                ws.send(message);
+            } else {
+                alert('WebSocket connection not established, please connect.');
+            }
+        }
+
+        function log(message) {
+            var console = document.getElementById('console');
+            var p = document.createElement('p');
+            p.style.wordWrap = 'break-word';
+            p.appendChild(document.createTextNode(message));
+            console.appendChild(p);
+            while (console.childNodes.length > 25) {
+                console.removeChild(console.firstChild);
+            }
+            console.scrollTop = console.scrollHeight;
+        }
+    </script>
+</head>
+<body>
+<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets rely on Javascript being enabled. Please enable
+    Javascript and reload this page!</h2></noscript>
+<div>
+    <div id="connect-container">
+        <div>
+            <input id="target" type="text" size="40" style="width: 350px" value="/echo"/>
+        </div>
+        <div>
+            <button id="connect" onclick="connect();">Connect</button>
+            <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
+        </div>
+        <div>
+            <textarea id="message" style="width: 350px">Here is a message!</textarea>
+        </div>
+        <div>
+            <button id="echo" onclick="echo();" disabled="disabled">Echo message</button>
+        </div>
+    </div>
+    <div id="console-container">
+        <div id="console"></div>
+    </div>
+</div>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/resources/static/index.html

@@ -0,0 +1,32 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Apache Tomcat WebSocket Examples: Index</title>
+</head>
+<body>
+<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets rely on Javascript being enabled. Please enable
+    Javascript and reload this page!</h2></noscript>
+<p>Please select the sample you would like to try.</p>
+<ul>
+    <li><a href="./echo.html">Echo</a></li>
+    <li><a href="./reverse.html">Reverse</a></li>
+    <li><a href="./snake.html">Snake</a></li>
+</ul>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/resources/static/reverse.html

@@ -0,0 +1,140 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!DOCTYPE html>
+<html>
+<head>
+    <title>WebSocket Examples: Reverse</title>
+    <style type="text/css">
+        #connect-container {
+            float: left;
+            width: 400px
+        }
+
+        #connect-container div {
+            padding: 5px;
+        }
+
+        #console-container {
+            float: left;
+            margin-left: 15px;
+            width: 400px;
+        }
+
+        #console {
+            border: 1px solid #CCCCCC;
+            border-right-color: #999999;
+            border-bottom-color: #999999;
+            height: 170px;
+            overflow-y: scroll;
+            padding: 5px;
+            width: 100%;
+        }
+
+        #console p {
+            padding: 0;
+            margin: 0;
+        }
+    </style>
+    <script type="text/javascript">
+        var ws = null;
+
+        function setConnected(connected) {
+            document.getElementById('connect').disabled = connected;
+            document.getElementById('disconnect').disabled = !connected;
+            document.getElementById('reverse').disabled = !connected;
+        }
+
+        function connect() {
+            var target = document.getElementById('target').value;
+            ws = new WebSocket(target);
+            ws.onopen = function () {
+                setConnected(true);
+                log('Info: WebSocket connection opened.');
+            };
+            ws.onmessage = function (event) {
+                log('Received: ' + event.data);
+            };
+            ws.onclose = function () {
+                setConnected(false);
+                log('Info: WebSocket connection closed.');
+            };
+        }
+
+        function updateTarget() {
+            if (window.location.protocol == 'http:') {
+                document.getElementById('target').value = 'ws://' + window.location.host + document.getElementById('target').value;
+            } else {
+                document.getElementById('target').value = 'wss://' + window.location.host + document.getElementById('target').value;
+            }
+        }
+
+        function disconnect() {
+            if (ws != null) {
+                ws.close();
+                ws = null;
+            }
+            setConnected(false);
+        }
+
+        function reverse() {
+            if (ws != null) {
+                var message = document.getElementById('message').value;
+                log('Sent: ' + message);
+                ws.send(message);
+            } else {
+                alert('WebSocket connection not established, please connect.');
+            }
+        }
+
+        function log(message) {
+            var console = document.getElementById('console');
+            var p = document.createElement('p');
+            p.style.wordWrap = 'break-word';
+            p.appendChild(document.createTextNode(message));
+            console.appendChild(p);
+            while (console.childNodes.length > 25) {
+                console.removeChild(console.firstChild);
+            }
+            console.scrollTop = console.scrollHeight;
+        }
+    </script>
+</head>
+<body onload="updateTarget()">
+<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets rely on Javascript being enabled. Please enable
+    Javascript and reload this page!</h2></noscript>
+<div>
+    <div id="connect-container">
+        <div>
+            <input id="target" type="text" size="40" style="width: 350px" value="/reverse"/>
+        </div>
+        <div>
+            <button id="connect" onclick="connect();">Connect</button>
+            <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
+        </div>
+        <div>
+            <textarea id="message" style="width: 350px">Here is a message!</textarea>
+        </div>
+        <div>
+            <button id="reverse" onclick="reverse();" disabled="disabled">Reverse message</button>
+        </div>
+    </div>
+    <div id="console-container">
+        <div id="console"></div>
+    </div>
+</div>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-websocket-undertow/src/main/resources/static/snake.html

@@ -0,0 +1,249 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
+<head>
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
+    <title>Apache Tomcat WebSocket Examples: Multiplayer Snake</title>
+    <style type="text/css">
+        #playground {
+            width: 640px;
+            height: 480px;
+            background-color: #000;
+        }
+
+        #console-container {
+            float: left;
+            margin-left: 15px;
+            width: 300px;
+        }
+
+        #console {
+            border: 1px solid #CCCCCC;
+            border-right-color: #999999;
+            border-bottom-color: #999999;
+            height: 480px;
+            overflow-y: scroll;
+            padding-left: 5px;
+            padding-right: 5px;
+            width: 100%;
+        }
+
+        #console p {
+            padding: 0;
+            margin: 0;
+        }
+    </style>
+    <script src="https://cdn.jsdelivr.net/sockjs/0.3.4/sockjs.min.js"></script>
+</head>
+<body>
+    <noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets rely on Javascript being enabled. Please enable
+    Javascript and reload this page!</h2></noscript>
+
+    <div style="float: left">
+        <canvas id="playground" width="640" height="480"></canvas>
+    </div>
+    <div id="console-container">
+        <div id="console"></div>
+    </div>
+    <script type="text/javascript">
+
+        var Game = {};
+
+        Game.fps = 30;
+        Game.socket = null;
+        Game.nextFrame = null;
+        Game.interval = null;
+        Game.direction = 'none';
+        Game.gridSize = 10;
+
+        function Snake() {
+            this.snakeBody = [];
+            this.color = null;
+        }
+
+        Snake.prototype.draw = function(context) {
+            for (var id in this.snakeBody) {
+                context.fillStyle = this.color;
+                context.fillRect(this.snakeBody[id].x, this.snakeBody[id].y, Game.gridSize, Game.gridSize);
+            }
+        };
+
+        Game.initialize = function() {
+            this.entities = [];
+            canvas = document.getElementById('playground');
+            if (!canvas.getContext) {
+                Console.log('Error: 2d canvas not supported by this browser.');
+                return;
+            }
+            this.context = canvas.getContext('2d');
+            window.addEventListener('keydown', function (e) {
+                var code = e.keyCode;
+                if (code > 36 && code < 41) {
+                    switch (code) {
+                        case 37:
+                            if (Game.direction != 'east') Game.setDirection('west');
+                            break;
+                        case 38:
+                            if (Game.direction != 'south') Game.setDirection('north');
+                            break;
+                        case 39:
+                            if (Game.direction != 'west') Game.setDirection('east');
+                            break;
+                        case 40:
+                            if (Game.direction != 'north') Game.setDirection('south');
+                            break;
+                    }
+                }
+            }, false);
+            Game.connect();
+        };
+
+        Game.setDirection  = function(direction) {
+            Game.direction = direction;
+            Game.socket.send(direction);
+            Console.log('Sent: Direction ' + direction);
+        };
+
+        Game.startGameLoop = function() {
+            if (window.webkitRequestAnimationFrame) {
+                Game.nextFrame = function () {
+                    webkitRequestAnimationFrame(Game.run);
+                };
+            } else if (window.mozRequestAnimationFrame) {
+                Game.nextFrame = function () {
+                    mozRequestAnimationFrame(Game.run);
+                };
+            } else {
+                Game.interval = setInterval(Game.run, 1000 / Game.fps);
+            }
+            if (Game.nextFrame != null) {
+                Game.nextFrame();
+            }
+        };
+
+        Game.stopGameLoop = function () {
+            Game.nextFrame = null;
+            if (Game.interval != null) {
+                clearInterval(Game.interval);
+            }
+        };
+
+        Game.draw = function() {
+            this.context.clearRect(0, 0, 640, 480);
+            for (var id in this.entities) {
+                this.entities[id].draw(this.context);
+            }
+        };
+
+        Game.addSnake = function(id, color) {
+            Game.entities[id] = new Snake();
+            Game.entities[id].color = color;
+        };
+
+        Game.updateSnake = function(id, snakeBody) {
+            if (typeof Game.entities[id] != "undefined") {
+                Game.entities[id].snakeBody = snakeBody;
+            }
+        };
+
+        Game.removeSnake = function(id) {
+            Game.entities[id] = null;
+            // Force GC.
+            delete Game.entities[id];
+        };
+
+        Game.run = (function() {
+            var skipTicks = 1000 / Game.fps, nextGameTick = (new Date).getTime();
+
+            return function() {
+                while ((new Date).getTime() > nextGameTick) {
+                    nextGameTick += skipTicks;
+                }
+                Game.draw();
+                if (Game.nextFrame != null) {
+                    Game.nextFrame();
+                }
+            };
+        })();
+
+        Game.connect = (function() {
+        	Game.socket = new SockJS("/snake");
+
+            Game.socket.onopen = function () {
+                // Socket open.. start the game loop.
+                Console.log('Info: WebSocket connection opened.');
+                Console.log('Info: Press an arrow key to begin.');
+                Game.startGameLoop();
+                setInterval(function() {
+                    // Prevent server read timeout.
+                    Game.socket.send('ping');
+                }, 5000);
+            };
+
+            Game.socket.onclose = function () {
+                Console.log('Info: WebSocket closed.');
+                Game.stopGameLoop();
+            };
+
+            Game.socket.onmessage = function (message) {
+                // _Potential_ security hole, consider using json lib to parse data in production.
+                var packet = eval('(' + message.data + ')');
+                switch (packet.type) {
+                    case 'update':
+                        for (var i = 0; i < packet.data.length; i++) {
+                            Game.updateSnake(packet.data[i].id, packet.data[i].body);
+                        }
+                        break;
+                    case 'join':
+                        for (var j = 0; j < packet.data.length; j++) {
+                            Game.addSnake(packet.data[j].id, packet.data[j].color);
+                        }
+                        break;
+                    case 'leave':
+                        Game.removeSnake(packet.id);
+                        break;
+                    case 'dead':
+                        Console.log('Info: Your snake is dead, bad luck!');
+                        Game.direction = 'none';
+                        break;
+                    case 'kill':
+                        Console.log('Info: Head shot!');
+                        break;
+                }
+            };
+        });
+
+        var Console = {};
+
+        Console.log = (function(message) {
+            var console = document.getElementById('console');
+            var p = document.createElement('p');
+            p.style.wordWrap = 'break-word';
+            p.innerHTML = message;
+            console.appendChild(p);
+            while (console.childNodes.length > 25) {
+                console.removeChild(console.firstChild);
+            }
+            console.scrollTop = console.scrollHeight;
+        });
+
+        Game.initialize();
+    </script>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-websocket-undertow/src/test/java/samples/websocket/SampleWebSocketsApplicationTests.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.test.IntegrationTest;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.web.socket.client.WebSocketConnectionManager;
+import org.springframework.web.socket.client.standard.StandardWebSocketClient;
+
+import samples.websocket.client.GreetingService;
+import samples.websocket.client.SimpleClientWebSocketHandler;
+import samples.websocket.client.SimpleGreetingService;
+import samples.websocket.config.SampleUndertowWebSocketsApplication;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = SampleUndertowWebSocketsApplication.class)
+@WebAppConfiguration
+@IntegrationTest("server.port:0")
+@DirtiesContext
+public class SampleWebSocketsApplicationTests {
+
+	private static Log logger = LogFactory.getLog(SampleWebSocketsApplicationTests.class);
+
+	@Value("${local.server.port}")
+	private int port = 1234;
+
+	@Test
+	public void echoEndpoint() throws Exception {
+		ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				ClientConfiguration.class, PropertyPlaceholderAutoConfiguration.class)
+				.properties(
+						"websocket.uri:ws://localhost:" + this.port + "/echo/websocket")
+				.run("--spring.main.web_environment=false");
+		long count = context.getBean(ClientConfiguration.class).latch.getCount();
+		AtomicReference<String> messagePayloadReference = context
+				.getBean(ClientConfiguration.class).messagePayload;
+		context.close();
+		assertEquals(0, count);
+		assertEquals("Did you say \"Hello world!\"?", messagePayloadReference.get());
+	}
+
+	@Test
+	public void reverseEndpoint() throws Exception {
+		ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				ClientConfiguration.class, PropertyPlaceholderAutoConfiguration.class)
+				.properties("websocket.uri:ws://localhost:" + this.port + "/reverse")
+				.run("--spring.main.web_environment=false");
+		long count = context.getBean(ClientConfiguration.class).latch.getCount();
+		AtomicReference<String> messagePayloadReference = context
+				.getBean(ClientConfiguration.class).messagePayload;
+		context.close();
+		assertEquals(0, count);
+		assertEquals("Reversed: !dlrow olleH", messagePayloadReference.get());
+	}
+
+	@Configuration
+	static class ClientConfiguration implements CommandLineRunner {
+
+		@Value("${websocket.uri}")
+		private String webSocketUri;
+
+		private final CountDownLatch latch = new CountDownLatch(1);
+
+		private final AtomicReference<String> messagePayload = new AtomicReference<String>();
+
+		@Override
+		public void run(String... args) throws Exception {
+			logger.info("Waiting for response: latch=" + this.latch.getCount());
+			if (this.latch.await(10, TimeUnit.SECONDS)) {
+				logger.info("Got response: " + this.messagePayload.get());
+			}
+			else {
+				logger.info("Response not received: latch=" + this.latch.getCount());
+			}
+		}
+
+		@Bean
+		public WebSocketConnectionManager wsConnectionManager() {
+
+			WebSocketConnectionManager manager = new WebSocketConnectionManager(client(),
+					handler(), this.webSocketUri);
+			manager.setAutoStartup(true);
+
+			return manager;
+		}
+
+		@Bean
+		public StandardWebSocketClient client() {
+			return new StandardWebSocketClient();
+		}
+
+		@Bean
+		public SimpleClientWebSocketHandler handler() {
+			return new SimpleClientWebSocketHandler(greetingService(), this.latch,
+					this.messagePayload);
+		}
+
+		@Bean
+		public GreetingService greetingService() {
+			return new SimpleGreetingService();
+		}
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/test/java/samples/websocket/echo/CustomContainerWebSocketsApplicationTests.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.echo;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
+import org.springframework.boot.context.embedded.undertow.UndertowEmbeddedServletContainerFactory;
+import org.springframework.boot.test.IntegrationTest;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.util.SocketUtils;
+import org.springframework.web.socket.client.WebSocketConnectionManager;
+import org.springframework.web.socket.client.standard.StandardWebSocketClient;
+
+import samples.websocket.client.GreetingService;
+import samples.websocket.client.SimpleClientWebSocketHandler;
+import samples.websocket.client.SimpleGreetingService;
+import samples.websocket.config.SampleUndertowWebSocketsApplication;
+import samples.websocket.echo.CustomContainerWebSocketsApplicationTests.CustomContainerConfiguration;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = { SampleUndertowWebSocketsApplication.class,
+		CustomContainerConfiguration.class })
+@WebAppConfiguration
+@IntegrationTest
+@DirtiesContext
+public class CustomContainerWebSocketsApplicationTests {
+
+	private static Log logger = LogFactory
+			.getLog(CustomContainerWebSocketsApplicationTests.class);
+
+	private static int PORT = SocketUtils.findAvailableTcpPort();
+
+	@Configuration
+	protected static class CustomContainerConfiguration {
+		@Bean
+		public EmbeddedServletContainerFactory embeddedServletContainerFactory() {
+			return new UndertowEmbeddedServletContainerFactory("/ws", PORT);
+		}
+	}
+
+	@Test
+	public void echoEndpoint() throws Exception {
+		ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				ClientConfiguration.class, PropertyPlaceholderAutoConfiguration.class)
+				.properties("websocket.uri:ws://localhost:" + PORT + "/ws/echo/websocket")
+				.run("--spring.main.web_environment=false");
+		long count = context.getBean(ClientConfiguration.class).latch.getCount();
+		AtomicReference<String> messagePayloadReference = context
+				.getBean(ClientConfiguration.class).messagePayload;
+		context.close();
+		assertEquals(0, count);
+		assertEquals("Did you say \"Hello world!\"?", messagePayloadReference.get());
+	}
+
+	@Test
+	public void reverseEndpoint() throws Exception {
+		ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				ClientConfiguration.class, PropertyPlaceholderAutoConfiguration.class)
+				.properties("websocket.uri:ws://localhost:" + PORT + "/ws/reverse").run(
+						"--spring.main.web_environment=false");
+		long count = context.getBean(ClientConfiguration.class).latch.getCount();
+		AtomicReference<String> messagePayloadReference = context
+				.getBean(ClientConfiguration.class).messagePayload;
+		context.close();
+		assertEquals(0, count);
+		assertEquals("Reversed: !dlrow olleH", messagePayloadReference.get());
+	}
+
+	@Configuration
+	static class ClientConfiguration implements CommandLineRunner {
+
+		@Value("${websocket.uri}")
+		private String webSocketUri;
+
+		private final CountDownLatch latch = new CountDownLatch(1);
+
+		private final AtomicReference<String> messagePayload = new AtomicReference<String>();
+
+		@Override
+		public void run(String... args) throws Exception {
+			logger.info("Waiting for response: latch=" + this.latch.getCount());
+			if (this.latch.await(10, TimeUnit.SECONDS)) {
+				logger.info("Got response: " + this.messagePayload.get());
+			}
+			else {
+				logger.info("Response not received: latch=" + this.latch.getCount());
+			}
+		}
+
+		@Bean
+		public WebSocketConnectionManager wsConnectionManager() {
+
+			WebSocketConnectionManager manager = new WebSocketConnectionManager(client(),
+					handler(), this.webSocketUri);
+			manager.setAutoStartup(true);
+
+			return manager;
+		}
+
+		@Bean
+		public StandardWebSocketClient client() {
+			return new StandardWebSocketClient();
+		}
+
+		@Bean
+		public SimpleClientWebSocketHandler handler() {
+			return new SimpleClientWebSocketHandler(greetingService(), this.latch,
+					this.messagePayload);
+		}
+
+		@Bean
+		public GreetingService greetingService() {
+			return new SimpleGreetingService();
+		}
+	}
+
+}

spring-boot-samples/spring-boot-sample-websocket-undertow/src/test/java/samples/websocket/snake/SnakeTimerTests.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package samples.websocket.snake;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.BDDMockito.willThrow;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.mock;
+
+public class SnakeTimerTests {
+
+	@Test
+	public void removeDysfunctionalSnakes() throws Exception {
+		Snake snake = mock(Snake.class);
+		willThrow(new IOException()).given(snake).sendMessage(anyString());
+		SnakeTimer.addSnake(snake);
+
+		SnakeTimer.broadcast("");
+		assertThat(SnakeTimer.getSnakes().size(), is(0));
+	}
+}