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
落日流年 人气:0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>
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