1. 导入相关依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
使用springboot的时候才需要注入bean。
因为springboot使用的是内置tomcat不支持websocket。如果使用外置的tomcat就可以直接删除。
2. WebSocketConfig
启用WebSocket的支持也是很简单，几句代码搞定
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
/**
* 开启WebSocket支持
*/
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
3.WebSocketServer
@ServerEndpoint("/imserver/{userId}") 相当于一个control 这个control是一个基于WebSocket的请求
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;
@ServerEndpoint("/imserver/{userId}")
@Component
public class WebSocketServer {
/**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。*/
private static int onlineCount = 0;
/**concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。*/
private static ConcurrentHashMap<String,WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
/**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*/
private Session session;
/**接收userId*/
private String userId="";
/**
* 连接建立成功调用的方法*/
@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();
//在线数加1
}
System.out.println("用户连接:"+userId+",当前在线人数为:" + getOnlineCount());
try {
sendMessage("连接成功");
} catch (IOException e) {
System.out.println("用户:"+userId+",网络异常!!!!!!");
}
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose() {
if(webSocketMap.containsKey(userId)){
webSocketMap.remove(userId);
//从set中删除
subOnlineCount();
}
System.out.println("用户退出:"+userId+",当前在线人数为:" + getOnlineCount());
}
/**
* 收到客户端消息后调用的方法
*
* @param message 客户端发送过来的消息*/
@OnMessage
public void onMessage(String message, Session session) {
System.out.println(session);
System.out.println("用户消息:"+userId+",报文:"+message);
//可以群发消息
//消息保存到数据库、redis
if(StringUtils.isNotBlank(message)){
try {
System.out.println(message);
//解析发送的报文
JSONObject jsonObject = JSON.parseObject(message);
//追加发送人(防止串改)
jsonObject.put("fromUserId",this.userId);
String toUserId=jsonObject.getString("toUserId");
//传送给对应toUserId用户的websocket
if(StringUtils.isNotBlank(toUserId)&&webSocketMap.containsKey(toUserId)){
webSocketMap.get(toUserId).sendMessage(jsonObject.toJSONString());
}else{
System.out.println("请求的userId:"+toUserId+"不在该服务器上");
//否则不在这个服务器上，发送到mysql或者redis
}
}catch (Exception e){
e.printStackTrace();
}
}
}
/**
*
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
System.out.println("用户错误:"+this.userId+",原因:"+error.getMessage());
error.printStackTrace();
}
/**
* 实现服务器主动推送
*/
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
/**
* 发送自定义消息
* */
public static void sendInfo(String message,@PathParam("userId") String userId) throws IOException {
System.out.println("发送消息到:"+userId+"，报文:"+message);
if(StringUtils.isNotBlank(userId)&&webSocketMap.containsKey(userId)){
webSocketMap.get(userId).sendMessage(message);
}else{
System.out.println("用户"+userId+",不在线！");
}
}
public static synchronized int getOnlineCount() {
return onlineCount;
}
public static synchronized void addOnlineCount() {
WebSocketServer.onlineCount++;
}
public static synchronized void subOnlineCount() {
WebSocketServer.onlineCount--;
}
}
4.前端页面
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>websocket通讯</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
let socket;
function openSocket() {
if (typeof (WebSocket) == "undefined") {
console.log("您的浏览器不支持WebSocket");
} else {
console.log("您的浏览器支持WebSocket");
//实现化WebSocket对象，指定要连接的服务器地址与端口 建立连接
//等同于socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
//var socketUrl="${request.contextPath}/im/"+$("#userId").val();
let socketUrl = "http://localhost:8888/chatserver//" + $("#userId").val();
socketUrl = socketUrl.replace("https", "ws").replace("http", "ws");
console.log(socketUrl);
if (socket != null) {
socket.close();
socket = null;
}
socket = new WebSocket(socketUrl);
//打开事件
socket.onopen = function () {
console.log("websocket已打开");
//socket.send("这是来自客户端的消息" + location.href + new Date());
};
//获得消息事件
socket.onmessage = function (msg) {
console.log(msg.data);
//发现消息进入 开始处理前端触发逻辑
};
//关闭事件
socket.onclose = function () {
console.log("websocket已关闭");
};
//发生了错误事件
socket.onerror = function () {
console.log("websocket发生了错误");
}
}
}
function sendMessage() {
if (typeof (WebSocket) == "undefined") {
console.log("您的浏览器不支持WebSocket");
} else {
console.log("您的浏览器支持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】：<a onclick="openSocket()">开启socket</a>
<p>【操作】：<a onclick="sendMessage()">发送消息</a>
</body>
</html>
