SpringBoot2.0集成WebSocket實現後臺向前端推送信息

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * 開啟WebSocket支持
 * @author zhengkai.blog.csdn.net
 */
@Configuration 
public class WebSocketConfig { 
	
 @Bean 
 public ServerEndpointExporter serverEndpointExporter() { 
 return new ServerEndpointExporter(); 
 } 
 
} 

package com.softdev.system.demo.config;

import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.springframework.stereotype.Component;
import cn.hutool.log.Log;
import cn.hutool.log.LogFactory;


/**
 * @author zhengkai.blog.csdn.net
 */
@ServerEndpoint("/imserver/{userId}")
@Component
public class WebSocketServer {

 static Log log=LogFactory.get(WebSocketServer.class);
 /**靜態變量，用來記錄當前在線連接數。應該把它設計成線程安全的。*/
 private static int onlineCount = 0;
 /**concurrent包的線程安全Set，用來存放每個客戶端對應的MyWebSocket對象。*/
 private static ConcurrentHashMap<String,WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
 /**與某個客戶端的連接會話，需要通過它來給客戶端發送數據*/
 private Session session;
 /**接收userId*/
 private String userId="";

 /**
 * 連接建立成功調用的方法*/
 @OnOpen
 public void onOpen(Session session,@PathParam("userId") String userId) {
 this.session = session;
 this.userId=userId;
 if(webSocketMap.containsKey(userId)){
 webSocketMap.remove(userId);
 webSocketMap.put(userId,this);
 //加入set中
 }else{
 webSocketMap.put(userId,this);
 //加入set中
 addOnlineCount();
 //在線數加1
 }

 log.info("用戶連接:"+userId+",當前在線人數為:" + getOnlineCount());

 try {
 sendMessage("連接成功");
 } catch (IOException e) {
 log.error("用戶:"+userId+",網絡異常!!!!!!");
 }
 }

 /**
 * 連接關閉調用的方法
 */
 @OnClose
 public void onClose() {
 if(webSocketMap.containsKey(userId)){
 webSocketMap.remove(userId);
 //從set中刪除
 subOnlineCount();
 }
 log.info("用戶退出:"+userId+",當前在線人數為:" + getOnlineCount());
 }

 /**
 * 收到客戶端消息後調用的方法
 *
 * @param message 客戶端發送過來的消息*/
 @OnMessage
 public void onMessage(String message, Session session) {
 log.info("用戶消息:"+userId+",報文:"+message);
 //可以群發消息
 //消息保存到數據庫、redis
 if(StringUtils.isNotBlank(message)){
 try {
 //解析發送的報文
 JSONObject jsonObject = JSON.parseObject(message);
 //追加發送人(防止串改)
 jsonObject.put("fromUserId",this.userId);
 String toUserId=jsonObject.getString("toUserId");
 //傳送給對應toUserId用戶的websocket
 if(StringUtils.isNotBlank(toUserId)&&webSocketMap.containsKey(toUserId)){
 webSocketMap.get(toUserId).sendMessage(jsonObject.toJSONString());
 }else{
 log.error("請求的userId:"+toUserId+"不在該服務器上");
 //否則不在這個服務器上，發送到mysql或者redis
 }
 }catch (Exception e){
 e.printStackTrace();
 }
 }
 }

 /**
 *
 * @param session
 * @param error
 */
 @OnError
 public void onError(Session session, Throwable error) {
 log.error("用戶錯誤:"+this.userId+",原因:"+error.getMessage());
 error.printStackTrace();
 }
 /**
 * 實現服務器主動推送
 */
 public void sendMessage(String message) throws IOException {
 this.session.getBasicRemote().sendText(message);
 }


 /**
 * 發送自定義消息
 * */
 public static void sendInfo(String message,@PathParam("userId") String userId) throws IOException {
 log.info("發送消息到:"+userId+"，報文:"+message);
 if(StringUtils.isNotBlank(userId)&&webSocketMap.containsKey(userId)){
 webSocketMap.get(userId).sendMessage(message);
 }else{
 log.error("用戶"+userId+",不在線！");
 }
 }

 public static synchronized int getOnlineCount() {
 return onlineCount;
 }

 public static synchronized void addOnlineCount() {
 WebSocketServer.onlineCount++;
 }

 public static synchronized void subOnlineCount() {
 WebSocketServer.onlineCount--;
 }
}

import com.softdev.system.demo.config.WebSocketServer;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import java.io.IOException;

/**
 * WebSocketController
 * @author zhengkai.blog.csdn.net
 */
@RestController
public class DemoController {

 @GetMapping("index")
 public ResponseEntity<String> index(){
 return ResponseEntity.ok("請求成功");
 }

 @GetMapping("page")
 public ModelAndView page(){
 return new ModelAndView("websocket");
 }

 @RequestMapping("/push/{toUserId}")
 public ResponseEntity<String> pushToWeb(String message, @PathVariable String toUserId) throws IOException {
 WebSocketServer.sendInfo(message,toUserId);
 return ResponseEntity.ok("MSG SEND SUCCESS");
 }
}

<!DOCTYPE html>
<html>
<head>
 <meta charset="utf-8">
 <title>websocket通訊</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
 var socket;
 function openSocket() {
 if(typeof(WebSocket) == "undefined") {
 console.log("您的瀏覽器不支持WebSocket");
 }else{
 console.log("您的瀏覽器支持WebSocket");
 //實現化WebSocket對象，指定要連接的服務器地址與端口 建立連接
 //等同於socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
 //var socketUrl="${request.contextPath}/im/"+$("#userId").val();
 var socketUrl="http://localhost:9999/demo/imserver/"+$("#userId").val();
 socketUrl=socketUrl.replace("https","ws").replace("http","ws");
 console.log(socketUrl);
 if(socket!=null){
 socket.close();
 socket=null;
 }
 socket = new WebSocket(socketUrl);
 //打開事件
 socket.onopen = function() {
 console.log("websocket已打開");
 //socket.send("這是來自客戶端的消息" + location.href + new Date());
 };
 //獲得消息事件
 socket.onmessage = function(msg) {
 console.log(msg.data);
 //發現消息進入 開始處理前端觸發邏輯
 };
 //關閉事件
 socket.onclose = function() {
 console.log("websocket已關閉");
 };
 //發生瞭錯誤事件
 socket.onerror = function() {
 console.log("websocket發生瞭錯誤");
 }
 }
 }
 function sendMessage() {
 if(typeof(WebSocket) == "undefined") {
 console.log("您的瀏覽器不支持WebSocket");
 }else {
 console.log("您的瀏覽器支持WebSocket");
 console.log('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
 socket.send('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
 }
 }
</script>
<body>
<p>【userId】：<div><input id="userId" name="userId" type="text" value="10"></div>
<p>【toUserId】：<div><input id="toUserId" name="toUserId" type="text" value="20"></div>
<p>【toUserId】：<div><input id="contentText" name="contentText" type="text" value="hello websocket"></div>
<p>【操作】：<div><a onclick="openSocket()">開啟socket</a></div>
<p>【操作】：<div><a onclick="sendMessage()">發送消息</a></div>
</body>

</html>

<script>
export default {
 data() {
 return {
 socket:null,
 userId:localStorage.getItem("ms_uuid"),
 toUserId:'2',
 content:'3'
 }
 },
 methods: {
 openSocket() {
 if (typeof WebSocket == "undefined") {
 console.log("您的瀏覽器不支持WebSocket");
 } else {
 console.log("您的瀏覽器支持WebSocket");
 //實現化WebSocket對象，指定要連接的服務器地址與端口 建立連接
 //等同於socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
 //var socketUrl="${request.contextPath}/im/"+$("#userId").val();
 var socketUrl =
 "http://localhost:8081/imserver/" + this.userId;
 socketUrl = socketUrl.replace("https", "ws").replace("http", "ws");
 console.log(socketUrl);
 if (this.socket != null) {
 this.socket.close();
 this.socket = null;
 }
 this.socket = new WebSocket(socketUrl);
 //打開事件
 this.socket = new WebSocket(socketUrl);
 //打開事件
 this.socket.onopen = function() {
 console.log("websocket已打開");
 //socket.send("這是來自客戶端的消息" + location.href + new Date());
 };
 //獲得消息事件
 this.socket.onmessage = function(msg) {
 console.log(msg.data);
 //發現消息進入 開始處理前端觸發邏輯
 };
 //關閉事件
 this.socket.onclose = function() {
 console.log("websocket已關閉");
 };
 //發生瞭錯誤事件
 this.socket.onerror = function() {
 console.log("websocket發生瞭錯誤");
 };
 }
 },
 sendMessage() {
 if (typeof WebSocket == "undefined") {
 console.log("您的瀏覽器不支持WebSocket");
 } else {
 console.log("您的瀏覽器支持WebSocket");
 console.log(
 '{"toUserId":"' +
 this.toUserId +
 '","contentText":"' +
 this.content +
 '"}'
 );
 this.socket.send(
 '{"toUserId":"' +
 this.toUserId +
 '","contentText":"' +
 this.content +
 '"}'
 );
 
 }
}