在开发一个项目的时候使用到了WebSocket协议

1. 什么是WebSocket?　　

　　　　　　WebSocket使得客户端和服务器之间的数据交换变得更加简单，允许服务端主动向客户端推送数据。在WebSocket API中，浏览器和服务器只需要完成一次握手，两者之间就直接可以创建持久性的连接，并进行双向数据传输。

　　 2.使用

 

• • • 工具类　
      1 package com.mz.usps.common.component;  2   3 import org.apache.log4j.Logger;  4 import org.springframework.stereotype.Component;  5   6 import javax.websocket.*;  7 import javax.websocket.server.PathParam;  8 import javax.websocket.server.ServerEndpoint;  9 import java.io.IOException; 10 import java.util.concurrent.ConcurrentHashMap; 11 import java.util.concurrent.ConcurrentMap; 12  13 //该注解用来指定一个URI，客户端可以通过这个URI来连接到WebSocket。类似Servlet的注解mapping。无需在web.xml中配置。 14 @ServerEndpoint("/webSocket/{id}") 15 @Component("webSocket") 16 public class WebSocket { 17  18     private static Logger logger = Logger.getLogger(WebSocket.class); 19     //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。 20     private static int onlineCount = 0; 21     //与某个客户端的连接会话，需要通过它来给客户端发送数据 22     private Session session; 23     //concurrent包的线程安全Map，用来存放每个客户端对应的MyWebSocket对象。若要实现服务端与单一客户端通信的话，可以使用Map来存放，其中Key可以为用户标识 24     private static ConcurrentMap
                 
                   webSocketMap = new ConcurrentHashMap<>(); 25     private static ConcurrentMap
                  
                    webSocketMapAdmin = new ConcurrentHashMap<>(); 26  27     public Session getSession() { 28         return session; 29     } 30  31     public static WebSocket getWebSocket(String id) { 32         return webSocketMap.get(id); 33     } 34  35     /** 36      * 连接建立成功调用的方法 37      * 38      * @param session 可选的参数。session为与某个客户端的连接会话，需要通过它来给客户端发送数据 39      */ 40     @OnOpen 41     public void onOpen(Session session, @PathParam("id") String id) { 42         this.session = session; 43         //String sessionId = session.getId(); 44         webSocketMap.put(id, this);     //加入map中 45         if (id.contains("admin")) {
               // 后台登陆用户，加入list 46             webSocketMapAdmin.put(id, this); 47         } 48         addOnlineCount();           //在线数加1 49         System.out.println("有新连接加入！当前在线人数为" + getOnlineCount()); 50     } 51  52     /** 53      * 连接关闭调用的方法 54      */ 55     @OnClose 56     public void onClose(@PathParam("id") String id) { 57         webSocketMap.remove(id);  //从map中删除 58         webSocketMapAdmin.remove(id); 59         subOnlineCount();           //在线数减1 60         System.out.println("有一连接关闭！当前在线人数为" + getOnlineCount()); 61     } 62  63     /** 64      * 收到客户端消息后调用的方法 65      * 66      * @param message 客户端发送过来的消息 67      * @param session 可选的参数 68      */ 69     @OnMessage 70     public static void onMessage(String message, Session session) { 71         //群发消息 72         if (webSocketMapAdmin.size() > 0) { 73             for (WebSocket item : webSocketMapAdmin.values()) { 74                 try { 75                     //System.out.println(item.session.getId()); 76                     item.session.getBasicRemote().sendText(message); 77                 } catch (IOException e) { 78                     logger.error("IO异常"); 79                     continue; 80                 } 81             } 82         } 83  84     } 85  86     /** 87      * 发生错误时调用 88      * 89      * @param session 90      * @param error 91      */ 92     @OnError 93     public void onError(Session session, Throwable error) { 94         //System.out.println("发生错误"); 95         logger.error("发生错误"); 96     } 97  98     /** 99      * 这个方法与上面几个方法不一样。没有用注解，是根据自己需要添加的方法。100      *101      * @param message102      * @throws IOException103      */104     public void sendMessage(String message) throws IOException {105         this.session.getBasicRemote().sendText(message);106         //this.session.getAsyncRemote().sendText(message);107     }108 109     public static synchronized int getOnlineCount() {110         return onlineCount;111     }112 113     public static synchronized void addOnlineCount() {114         WebSocket.onlineCount++;115     }116 117     public static synchronized void subOnlineCount() {118         WebSocket.onlineCount--;119     }120 121     public static void main(String[] args) {122         /*WebSocket webSocket = new WebSocket();123         System.out.println(webSocket);124         webSocketMap.put("1", webSocket);125         webSocketMap.put("1", webSocket);126         System.out.println(webSocketMap.get("12"));*/127         onMessage("123465",null);128     }129 }
                  
                 
    • 微信登录成功时将用户信息发送给前端
    • 1 /**  2      * 手机端微信登陆  3      *  4      * @return  5      */  6     @RequestMapping(value = "/wxLogin", method = RequestMethod.GET)  7     @ResponseBody  8     public R wxLogin(String userResult, String state, @RequestParam(required = false, value = "userId") String userId) throws Exception {  9         //System.out.println(userResult+"\n"+state+"\n"+userId); 10         WxUser wxUser = JSON.parseObject(userResult, WxUser.class); 11         UserInfo userInfo = new UserInfo(); 12         userInfo.setUnionId(wxUser.getUnionid()); 13         userInfo.setOpenid(wxUser.getOpenid()); 14         userInfo.setSex((long) wxUser.getSex()); 15         userInfo.setHeadImgUrl(wxUser.getHeadimgurl()); 16         if (EmojiUtil.containsEmoji(wxUser.getNickName())) { 17             logger.info(wxUser.getNickName()); 18             userInfo.setNickName(EmojiUtil.emojiConverterToAlias(wxUser.getNickName())); 19         } else { 20             userInfo.setNickName(wxUser.getNickName()); 21         } 22         System.out.println(userInfo.getUnionId()); 23         UserInfo userInfo1; 24         WebSocket webSocket = WebSocket.getWebSocket(state); 25         Map
                 
                   m = new HashMap<>(); 26         //登录 27         if (userId == null || "".equals(userId)) { 28             if ((userInfo1 = userInfoService.selectWx(userInfo)) != null) { 29                 //判定账号是否被禁用 30                 if (userInfo1.getUserState() != 1) { 31                     R r = new R(); 32                     r.put("code", 500); 33                     r.put("msg", "此账号因为特殊原因已被禁用,若想重新启用,请联系管理员"); 34                     webSocket.sendMessage(JSON.toJSONString(r)); 35                     return null; 36                 } 37  38                 userInfo.setUserId(userInfo1.getUserId()); 39                 //System.out.println(userInfo1.getHeadImgUrl()+"你好呀"); 40                 if (userInfo1.getHeadImgUrl() != null) { 41                     userInfo.setHeadImgUrl(null); 42                 } 43                 //System.out.println(userInfo.getHeadImgUrl()+"你好"); 44                 userInfoService.updateByPrimaryKeySelective(userInfo); 45                 UserInfo userInfo2 = userInfoService.selectWx(userInfo); 46                 if (EmojiUtil.containsEmoji(userInfo2.getNickName())) { 47                     userInfo2.setNickName(EmojiUtil.emojiConverterUnicodeStr(userInfo2.getNickName())); 48                 } 49                 m.put("openId", userInfo2.getOpenid()); 50                 m.put("userId", userInfo2.getUserId()); 51                 m.put("createTime", new Date()); 52                 String javaWebToken = WebTokenUtil.createJavaWebToken(m); 53                 userInfo2.setToken(javaWebToken); 54                 redisCache.setValue(javaWebToken, "1", 1, TimeUnit.DAYS); 55                 webSocket.sendMessage(JSON.toJSONString(userInfo2));//登录用户信息发送给web 56                 return R.ok("登录成功"); 57             } else { 58                 userInfo.setUserName(userInfo.getNickName()); 59                 userInfoService.insertSelective(userInfo); 60                 UserInfo userInfo3 = userInfoService.selectWx(userInfo); 61                 if (EmojiUtil.containsEmoji(userInfo3.getNickName())) { 62                     userInfo3.setNickName(EmojiUtil.emojiConverterUnicodeStr(userInfo3.getNickName())); 63                 } 64                 //判定账号是否被禁用 65                 if (userInfo3.getUserState() != 1) { 66                     R r = new R(); 67                     r.put("code", 500); 68                     r.put("msg", "此账号因为特殊原因已被禁用,若想启用,请联系管理员"); 69                     webSocket.sendMessage(JSON.toJSONString(r)); 70                     return null; 71                 } 72  73                 System.out.println(userInfo.getOpenid()); 74                 m.put("openId", userInfo3.getOpenid()); 75                 m.put("userId", userInfo3.getUserId()); 76                 m.put("createTime", new Date()); 77                 String javaWebToken = WebTokenUtil.createJavaWebToken(m); 78                 userInfo3.setToken(javaWebToken); 79                 redisCache.setValue(javaWebToken, "1", 1, TimeUnit.DAYS); 80                 webSocket.sendMessage(JSON.toJSONString(userInfo3));//登录用户信息发送给web 81                 return R.ok("登录成功"); 82             } 83         } else { 84             userInfo.setUserId(Long.valueOf(userId)); 85             //绑定微信前先判断数据库中是否有头像,如果有,不更改头像 86             List
                  
                    selectmemberlist = userInfoService.selectmemberlist(userInfo); 87             if (selectmemberlist.get(0).getHeadImgUrl() != null) { 88                 userInfo.setHeadImgUrl(null); 89             } 90  91             UserInfo userInfo2 = userInfoService.selectWx(userInfo); 92             if (userInfo2 != null) { 93                 R r = new R(); 94                 r.put("code", 500); 95                 r.put("msg", "此微信已被注册,若确认是你本人微信,请联系管理员帮你更改"); 96                 webSocket.sendMessage(JSON.toJSONString(r)); 97                 return R.error(""); 98             } 99             if (EmojiUtil.containsEmoji(wxUser.getNickName())) {100                 userInfo.setNickName( EmojiUtil.emojiConverterToAlias(wxUser.getNickName()));101             }102             R r = userInfoService.updateByPrimaryKeySelective(userInfo);103             if (r.get("code").equals(200)) {104                 R r1 = new R();105                 r1.put("code", 200);106                 r1.put("msg", "更改成功");107                 webSocket.sendMessage(JSON.toJSONString(r1));108             } else {109                 R r2 = new R();110                 r2.put("code", 500);111                 r2.put("msg", "更改失败");112                 webSocket.sendMessage(JSON.toJSONString(r2));113             }114             return r;115         }116     }117 118 }