1.基本概念
WebSocket 支持双方通信即服务端可以主动推送给用户端,用户端也可以主动推送消息给服务器。前端必须进行协议升级为 WebSocket
名称 值 Upgrade websocket
2. 后端代码
package com.koshi.websocket.server;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
@Component
@Slf4j
@ServerEndpoint("/api/pushMessage/{userId}")
public class WebSocketServer {
/**静态变量,用来记录当前在线连接数*/
private static final AtomicInteger onlineCount = new Ato