大屏展示使用WebSocket记录
websocket是长连接技术,在大屏展示时可以使用websocket长连接技术从后端先前端推送数据。本文章记录的使用spring boot 技术为后端技术实现。过程如下:1.引入pom。<dependency><groupId>org.springframework.boot</groupId>...
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websocket是长连接技术,在大屏展示时可以使用websocket长连接技术从后端先前端推送数据。本文章记录的使用spring boot 技术为后端技术实现。过程如下:
1.引入pom。
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
2.WebSocketConfig 配置。
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
/**
* @Auther: wangb
* @Date: 2019/4/26/026 09:41
* @Description:
*/
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
3.创建controller,WebSocketServer
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import org.springframework.stereotype.Component;
/**
* @Auther: wangb
* @Date: 2019/4/26/026 10:28
* @Description:
*/
@ServerEndpoint(value = "/websocket")
@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。
public static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();
//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;
/**
* 连接建立成功调用的方法*/
@OnOpen
public void onOpen(Session session) {
this.session = session;
webSocketSet.add(this); //加入set中
addOnlineCount(); //在线数加1
System.out.println("有新连接加入!当前在线人数为" + getOnlineCount());
try {
sendMessage("连接成功...");
} catch (IOException e) {
System.out.println("websocket IO异常");
}
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose() {
webSocketSet.remove(this); //从set中删除
subOnlineCount(); //在线数减1
System.out.println("有一连接关闭!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("来自客户端的消息:" + message);
//群发消息
for (WebSocketServer item : webSocketSet) {
try {
item.sendMessage(message);
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
System.out.println("发生错误");
error.printStackTrace();
}
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
public void sendMessage(Object obj) throws IOException, EncodeException {
this.session.getBasicRemote().sendObject(obj);
}
/**
* 群发自定义消息
* */
public static void sendInfo(String message) throws IOException {
System.out.println(message);
for (WebSocketServer item : webSocketSet) {
try {
item.sendMessage(message);
} catch (IOException e) {
continue;
}
}
}
public static synchronized int getOnlineCount() {
return onlineCount;
}
public static synchronized void addOnlineCount() {
WebSocketServer.onlineCount++;
}
public static synchronized void subOnlineCount() {
WebSocketServer.onlineCount--;
}
}
4.创建前端页面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<script src="http://cdn.bootcss.com/sockjs-client/1.1.1/sockjs.min.js"></script>
<script src="http://cdn.bootcss.com/stomp.js/2.3.3/stomp.js"></script>
<script src="http://cdn.bootcss.com/jquery/3.1.1/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
var mesdivObj = document.getElementById("mesid");
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");
socket = new WebSocket("ws://localhost:8075/websocket");
//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) {
var pp = "<p>"+msg.data+"</p>"
$("#mesid").append(pp);
console.log(msg.data);
//发现消息进入 调后台获取
//getCallingList();
};
//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");
}
/* $(window).unload(function() {
socket.close();
}); */
$("#btnSend").click(function() {
socket.send("这是来自客户端的消息" + new Date());
console.log("这是来自客户端的消息" + new Date());
});
$("#btnClose").click(function() {
socket.close();
});
}
});
</script>
</head>
<body>
<button id="btnSend">推送消息</button>
----------------------
<button id="btnClose">关闭连接</button>
*******************************************************************
<div id="mesid">
</div>
</body>
</html>
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