java开发之使用websocket实现web客户端与服务器之间的实时通讯
第一次写博客，有写的不好的地方欢迎大家指点。使用websocket实现web客户端与服务器之间的实时通讯。以下是个简单的demo。 import java.util.Date; public class WebSocketMessage { /** * 发送者ID */ private String senderId; /** * 接受者ID, 如果为0, 则发送给所有人 */ private String receiverId; /** * 会话内容 */ private String messageContent; /** * 发送时间 */ private Date sendTime; public String getSenderId() { return senderId; } public void setSenderId(String senderId) { this.senderId = senderId; } public String getReceiverId() { return receiverId; } public void setReceiverId(String receiverId) { this.receiverId = receiverId; } public String getMessageContent() { return messageContent; } public void setMessageContent(String messageContent) { this.messageContent = messageContent; } public Date getSendTime() { return sendTime; } public void setSendTime(Date sendTime) { this.sendTime = sendTime; } } import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; @Controller @RequestMapping("webSocket") public class WebSocketController { @RequestMapping(value = "messagePage/{userID}") public ModelAndView messagePage(@PathVariable String userID, HttpServletResponse response) { ModelAndView mav = new ModelAndView(); mav.addObject("userID", userID); mav.setViewName("web_socket"); return mav; } } import java.io.IOException; import java.util.Map; 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.utime.facade.model.systemplate.WebSocketMessage; @ServerEndpoint("/webSocketServer/{userID}") public class WebSocketServer { // 连接客户端数量 private static int onlineCount = 0; // 所有的连接客户端 private static Map<String, WebSocketServer> clients = new ConcurrentHashMap<String, WebSocketServer>(); // 当前客户端连接的唯一标示 private Session session; // 当前客户端连接的用户ID private String userID; /** * 客户端连接服务端回调函数 * * @param userID 用户ID * @param session 会话 * @throws IOException */ @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("WebSocket日志: 有新连接加入！当前在线人数为" + getOnlineCount()); } @OnClose public void onClose() throws IOException { clients.remove(userID); subOnlineCount(); System.out.println("WebSocket日志: 有一连接关闭！当前在线人数为" + getOnlineCount()); } /** * 接受到来自客户端的消息 * * @param message * @throws IOException */ @OnMessage public void onMessage(String message) throws IOException { System.out.println("WebSocket日志: 来自客户端的消息:" + message); WebSocketMessage webSocketMessage = JSON.parseObject(message, WebSocketMessage.class); // 发送消息给所有客户端 if ("0".equals(webSocketMessage.getReceiverId())) { for (WebSocketServer item : clients.values()) { item.session.getAsyncRemote().sendText(webSocketMessage.getMessageContent()); System.out.println("WebSocket日志: ID为"+ webSocketMessage.getSenderId() +"的用户给ID为"+ item.userID +"的客户端发送:" + webSocketMessage.getMessageContent()); } } else { // 发送消息给指定ID的客户端 for (WebSocketServer item : clients.values()) { if (item.userID.equals(webSocketMessage.getReceiverId())){ // 发消息给指定客户端 item.session.getAsyncRemote().sendText(webSocketMessage.getMessageContent()); System.out.println("WebSocket日志: ID为"+ webSocketMessage.getSenderId() +"的用户给ID为"+ item.userID +"的客户端发送:" + webSocketMessage.getMessageContent()); if (!webSocketMessage.getSenderId().equals(webSocketMessage.getReceiverId())) { // 发消息给自己 this.session.getAsyncRemote().sendText(webSocketMessage.getMessageContent()); System.out.println("WebSocket日志: ID为"+ webSocketMessage.getSenderId() +"的用户给ID为"+ this.userID +"的客户端发送:" + webSocketMessage.getMessageContent()); } break; } } } } /** * 服务端报错了 * * @param session * @param error */ @OnError public void onError(Session session, Throwable error) { System.out.println("WebSocket日志: 发生错误"); error.printStackTrace(); } /** * 客户端连接数+1 */ public static synchronized void addOnlineCount() { WebSocketServer.onlineCount++; } /** * 客户端连接数-1 */ public static synchronized void subOnlineCount() { WebSocketServer.onlineCount--; } public static synchronized int getOnlineCount() { return onlineCount; } public static synchronized Map<String, WebSocketServer> getClients() { return clients; } } <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%> <%@taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fun"%> <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%> <c:set var="baseurl" value="${pageContext.request.contextPath}/"></c:set> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>web_socket</title> <script type="text/javascript" src="${baseurl}static/js/jquery-2.1.1.js"></script> <style type="text/css"> .connector {width: 500px;} </style> </head> <body> Welcome <br/> <input id="text" type="text"/> <button onclick="sendToOne(10008)">发消息给个人</button> <button onclick="sendToAll(0)">发消息给所有人</button> <hr/> <button onclick="closeWebSocket()">关闭WebSocket连接</button> <hr/> <div id="message"></div> </body> <script type="text/javascript"> var websocket = null; var host = document.location.host; //判断当前浏览器是否支持WebSocket if ('WebSocket' in window) { console.info("浏览器支持Websocket"); websocket = new WebSocket('ws://'+host+'/${baseurl}/webSocketServer/${userID}'); } else { console.info('当前浏览器 Not support websocket'); } //连接发生错误的回调方法 websocket.onerror = function() { console.info("WebSocket连接发生错误"); setMessageInnerHTML("WebSocket连接发生错误"); } //连接成功建立的回调方法 websocket.onopen = function() { console.info("WebSocket连接成功"); setMessageInnerHTML("WebSocket连接成功"); } //接收到消息的回调方法 websocket.onmessage = function(event) { console.info("接收到消息的回调方法"); console.info("这是后台推送的消息："+event.data); setMessageInnerHTML(event.data); console.info("webSocket已关闭！"); } //连接关闭的回调方法 websocket.onclose = function() { setMessageInnerHTML("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(); } //将消息显示在网页上 function setMessageInnerHTML(innerHTML) { document.getElementById('message').innerHTML += innerHTML + '<br/>'; } //发送消息给其他客户端 function sendToOne(receiverId) { var messageContent = document.getElementById('text').value; var message = {}; message.senderId = "${userID}"; message.receiverId = receiverId; message.messageContent = messageContent; websocket.send(JSON.stringify(message)); } //发送消息给所有人 function sendToAll() { var messageContent = document.getElementById('text').value; var message = {}; message.senderId = "${userID}"; message.receiverId = "0"; message.messageContent = messageContent; websocket.send(JSON.stringify(message)); } </script> </html> 写这个的目的只是为了自己做个记录。写的不好，后面会慢慢完善。
