Spring Boot 整合单机websocket(附github源码)
websocket 概念
websocket 是一个通信协议，通过单个 TCP 连接提供全双工通信。websocket 连接成功后，服务端和客户可以进行双向通信。不同于 http 通信协议需要每次由客户端发起，服务响应到客户端。
websocket 相对轮询也能节约带宽，并且能实时的进行通信。
整合步骤
1. 添加 maven 依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
<version>2.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
<version>2.1.3.RELEASE</version>
</dependency>
添加web、websocket和freemarker依赖。
2. 使用 ServerEndpointExporter 创建 bean
这个 bean 会自动注册声明 @ServerEndpoint 注解声明的 websocket endpoint，使用springboot自带tomcat启动需要该配置，使用独立 tomcat 则不需要该配置。
@Configuration
public class WebSocketConfig {
//tomcat启动无需该配置
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
3. 创建服务端端点 (ServerEndpoint)
@Component
@ServerEndpoint(value = "/message")
@Slf4j
public class WebSocket {
private static Map<String, WebSocket> webSocketSet = new ConcurrentHashMap<>();
private Session session;
@OnOpen
public void onOpen(Session session) throws SocketException {
this.session = session;
webSocketSet.put(this.session.getId(),this);
log.info("【websocket】有新的连接,总数:{}",webSocketSet.size());
}
@OnClose
public void onClose(){
String id = this.session.getId();
if (id != null){
webSocketSet.remove(id);
log.info("【websocket】连接断开:总数:{}",webSocketSet.size());
}
}
@OnMessage
public void onMessage(String message){
if (!message.equals("ping")){
log.info("【wesocket】收到客户端发送的消息,message={}",message);
sendMessage(message);
}
}
/**
* 发送消息
* @param message
* @return 全部都发送一遍
*/
public void sendMessage(String message){
for (WebSocket webSocket : webSocketSet.values()) {
webSocket.session.getAsyncRemote().sendText(message);
}
log.info("【wesocket】广播消息,message={}", message);
}
}
4. 添加 controller 和 客户端
- 添加 controller
@GetMapping({"","index.html"})
public ModelAndView index() {
ModelAndView view = new ModelAndView("index");
return view;
}
- 添加ftl页面
<!DOCTYPE html>
<html>
<head>
<title>websocket</title>
</head>
<body>
<div>
<input type="text" name="message" id="message">
<button id="sendBtn">发送</button>
</div>
<div style="width:100px;height: 500px;" id="content">
</div>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.js"></script>
<script type="text/javascript">
var ws = new WebSocket("ws://127.0.0.1:8080/message");
ws.onopen = function(evt) {
console.log("Connection open ...");
};
ws.onmessage = function(evt) {
console.log( "Received Message: " + evt.data);
var p = $("<p>"+evt.data+"</p>")
$("#content").prepend(p);
$("#message").val("");
};
ws.onclose = function(evt) {
console.log("Connection closed.");
};
$("#sendBtn").click(function(){
var aa = $("#message").val();
ws.send(aa);
})
</script>
</body>
</html>
5. 展示效果
