转http://zk-chs.iteye.com/blog/2285329
这次给大家说一下自己对websocket + spring boot结合使用的一些经验
首先websocket是一个持久化的协议,实现了浏览器与服务器的全双工通信。不再像http那样,只有在浏览器发出request之后才有response,websocket能实现服务器主动向浏览器发出消息。
下面我们用spring boot来实现一下:
在spring boot的文档中,介绍了我们需要配置的文件
- // pom.xml
- <dependency>
- <groupId>org.springframework.boot</groupId>
- <artifactId>spring-boot-starter-websocket</artifactId>
- </dependency>
- @Configuration
- public class WebSocketConfig {
- @Bean
- public ServerEndpointExporter serverEndpointExporter (){
- return new ServerEndpointExporter();
- }
- }
- @ServerEndpoint("/websocket")
- @Component
- public class MyWebSocket {
- private static int onlineCount = 0;
- private static CopyOnWriteArraySet<MyWebSocket> webSocketSet = new CopyOnWriteArraySet<>();
- private Session session;
- @OnOpen
- public void onOpen (Session session){
- this.session = session;
- webSocketSet.add(this);
- addOnlineCount();
- System.out.println("有新链接加入!当前在线人数为" + getOnlineCount());
- }
- @OnClose
- public void onClose (){
- webSocketSet.remove(this);
- subOnlineCount();
- System.out.println("有一链接关闭!当前在线人数为" + getOnlineCount());
- }
- @OnMessage
- public void onMessage (String message, Session session) throws IOException {
- System.out.println("来自客户端的消息:" + message);
- // 群发消息
- for ( MyWebSocket item : webSocketSet ){
- item.sendMessage(message);
- }
- }
- public void sendMessage (String message) throws IOException {
- this.session.getBasicRemote().sendText(message);
- }
- public static synchronized int getOnlineCount (){
- return MyWebSocket.onlineCount;
- }
- public static synchronized void addOnlineCount (){
- MyWebSocket.onlineCount++;
- }
- public static synchronized void subOnlineCount (){
- MyWebSocket.onlineCount--;
- }
- }
- <!DOCTYPE HTML>
- <html>
- <head>
- <base href="localhost://localhost:8080/">
- <title>My WebSocket</title>
- </head>
- <body>
- Welcome<br/>
- <input id="text" type="text"/>
- <button onclick="send()">Send</button>
- <button onclick="closeWebSocket()">Close</button>
- <div id="message">
- </div>
- </body>
- <script type="text/javascript">
- var websocket = null;
- //判断当前浏览器是否支持WebSocket
- if ('WebSocket' in window) {
- websocket = new WebSocket("ws://localhost:8080/websocket");
- }
- else {
- alert('Not support websocket')
- }
- //连接发生错误的回调方法
- websocket.onerror = function () {
- setMessageInnerHTML("error");
- };
- //连接成功建立的回调方法
- websocket.onopen = function (event) {
- setMessageInnerHTML("open");
- }
- //接收到消息的回调方法
- websocket.onmessage = function (event) {
- setMessageInnerHTML(event.data);
- }
- //连接关闭的回调方法
- websocket.onclose = function () {
- setMessageInnerHTML("close");
- }
- //监听窗口关闭事件,当窗口关闭时,主动去关闭websocket连接,防止连接还没断开就关闭窗口,server端会抛异常。
- window.onbeforeunload = function () {
- websocket.close();
- }
- //将消息显示在网页上
- function setMessageInnerHTML(innerHTML) {
- document.getElementById('message').innerHTML += innerHTML + '<br/>';
- }
- //关闭连接
- function closeWebSocket() {
- websocket.close();
- }
- //发送消息
- function send() {
- var message = document.getElementById('text').value;
- websocket.send(message);
- }
- </script>
- </html>