首先注入一个**ServerEndpointExporter**Bean,该Bean会自动注册使用@ServerEndpoint注解申明的websocket endpoint。代码如下：
```java
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter(){
return new ServerEndpointExporter();
}
}
```
3、申明endpoint
建立**MyWebSocket.java**类，在该类中处理websocket逻辑
```java
@ServerEndpoint(value = "/websocket") //接受websocket请求路径
@Component //注册到spring容器中
public class MyWebSocket {
//保存所有在线socket连接
private static Map webSocketMap = new LinkedHashMap<>();
//记录当前在线数目
private static int count=0;
//当前连接（每个websocket连入都会创建一个MyWebSocket实例
private Session session;
private Logger log = LoggerFactory.getLogger(this.getClass());
//处理连接建立
@OnOpen
public void onOpen(Session session){
this.session=session;
webSocketMap.put(session.getId(),this);
addCount();
log.info("新的连接加入：{}",session.getId());
}
//接受消息
@OnMessage
public void onMessage(String message,Session session){
log.info("收到客户端{}消息：{}",session.getId(),message);
try{
this.sendMessage("收到消息："+message);
}catch (Exception e){
e.printStackTrace();
}
}
//处理错误
@OnError
public void onError(Throwable error,Session session){
log.info("发生错误{},{}",session.getId(),error.getMessage());
}
//处理连接关闭
@OnClose
public void onClose(){
webSocketMap.remove(this.session.getId());
reduceCount();
log.info("连接关闭:{}",this.session.getId());
}
//群发消息
//发送消息
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
//广播消息
public static void broadcast(){
MyWebSocket.webSocketMap.forEach((k,v)->{
try{
v.sendMessage("这是一条测试广播");
}catch (Exception e){
}
});
}
//获取在线连接数目
public static int getCount(){
return count;
}
//操作count，使用synchronized确保线程安全
public static synchronized void addCount(){
MyWebSocket.count++;
}
public static synchronized void reduceCount(){
MyWebSocket.count--;
}
}
```