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呐喊教程。
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