java

关注公众号 jb51net

关闭
首页 > 软件编程 > java > WebSocket实现数据库更新时前端页面刷新

WebSocket实现数据库更新时前端页面刷新

作者:落日流年

这篇文章主要为大家详细介绍了WebSocket实现数据库更新时前端页面刷新,具有一定的参考价值,感兴趣的小伙伴们可以参考一下

本文实例为大家分享了WebSocket实现数据库更新时前端页面刷新,供大家参考,具体内容如下

后台代码:

WebSocketConfig:

package com.x.common.websocket;
 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
 
@Configuration
public class WebSocketConfig {
 @Bean
 public ServerEndpointExporter serverEndpointExporter() {
 return new ServerEndpointExporter();
 }
}

WebSocketServlet:

package com.x.common.websocket;
import com.alibaba.fastjson.JSONObject;
import org.springframework.stereotype.Component;
 
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
 
@ServerEndpoint("/websocket/{userId}")
@Component
public class WebSocketServlet {
 
 private static int onlineCount = 0;
 private static Map<String, WebSocketServlet> clients = new ConcurrentHashMap<>();
 private Session session;
 private String userId;
 
 @OnOpen
 public void onOpen(@PathParam("userId") String userId, Session session) throws IOException {
 
 this.userId = userId;
 this.session = session;
 
 addOnlineCount();
 clients.put(userId, this);
 System.out.println("已连接");
 }
 
 @OnClose
 public void onClose() throws IOException {
 clients.remove(userId);
 subOnlineCount();
 }
 
 @OnMessage
 public void onMessage(String message) throws IOException {
 
 JSONObject jsonTo = JSONObject.parseObject(message);
 
 if (!jsonTo.get("To").equals("All")){
 sendMessageTo("给一个人", jsonTo.get("To").toString());
 }else{
 sendMessageAll("给所有人");
 }
 }
 
 @OnError
 public void onError(Session session, Throwable error) {
 error.printStackTrace();
 }
 
 public void sendMessageTo(String message, String To) throws IOException {
 // session.getBasicRemote().sendText(message);
 //session.getAsyncRemote().sendText(message);
 for (WebSocketServlet item : clients.values()) {
 if (item.userId.equals(To) ){
 item.session.getAsyncRemote().sendText(message);
 }
 }
 }
 
 public void sendMessageAll(String message) throws IOException {
 for (WebSocketServlet item : clients.values()) {
 item.session.getAsyncRemote().sendText(message);
 }
 }
 
 
 public static synchronized int getOnlineCount() {
 return onlineCount;
 }
 
 public static synchronized void addOnlineCount() {
 WebSocketServlet.onlineCount++;
 }
 
 public static synchronized void subOnlineCount() {
 WebSocketServlet.onlineCount--;
 }
 
 public static synchronized Map<String, WebSocketServlet> getClients() {
 return clients;
 }
}

JS代码:

var websocket = null;
 
//判断当前浏览器是否支持WebSocket
if ('WebSocket' in window) {
 websocket = new WebSocket("ws://localhost:8086/websocket/1");
} else {
 alert('当前浏览器 Not support websocket')
}
 
//连接发生错误的回调方法
websocket.onerror = function() {
 console.log("WebSocket连接发生错误");
};
 
//连接成功建立的回调方法
websocket.onopen = function() {
 console.log("WebSocket连接成功");
}
 
//接收到消息的回调方法
websocket.onmessage = function(event) {
 //返回数据转JSON
 var json=JSON.parse(event.data);
 //result为bootstrap table 返回数据
 var rows=result.rows;
 for(var i=0;i<rows.length;i++){
 var row=rows[i];
 if(row.id==json.id){
 //判断列Id相同时刷新表格
 //$('#dataGrid').bootstrapTable('updateByUniqueId', {index: i, row: row});'refresh'
 $('#dataGrid').bootstrapTable('refresh');
 }
 }
 console.log(event.data);
}
 
//连接关闭的回调方法
websocket.onclose = function() {
 console.log("WebSocket连接关闭");
}
 
//监听窗口关闭事件,当窗口关闭时,主动去关闭websocket连接,防止连接还没断开就关闭窗口,server端会抛异常。
window.onbeforeunload = function() {
 closeWebSocket();
}
 
//关闭WebSocket连接
function closeWebSocket() {
 websocket.close();
}

返回前台是调用方法:

@Autowired
private WebSocketServlet scoket;
 
//学生信息
XStudentInfoEntity student = xStudentInfoService.getObjectById(id.replace("\"",""));
//提醒学生数据发生改变
scoket.sendMessageAll(JSONObject.toJSONString(student));

pom.xml: 

<dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-websocket</artifactId>
</dependency>

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

您可能感兴趣的文章:
阅读全文