WebSocket实现简单的web聊天室 1.需要Tomcat7.0所以服务器 2.需要JDK7.0 3.手工加入Tomcat7.0中lib目录下的一下三个包catalina.jar、tomcat-coyote.jar、websocket-api.jar 4.项目部署后，请将服务器中当前项目下的catalina.jar、tomcat-coyote.jar、websocket-api.jar三个包删除。 5.项目目录结构如下
Servlet代码
package com.yc.websockets;
import java.io.IOException; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.util.ArrayList; import java.util.List;
import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import javax.websocket.OnClose; import javax.websocket.OnMessage; import javax.websocket.OnOpen; import javax.websocket.Session; import javax.websocket.server.ServerEndpoint;
import org.apache.catalina.websocket.MessageInbound; import org.apache.catalina.websocket.StreamInbound; import org.apache.catalina.websocket.WebSocketServlet; import org.apache.catalina.websocket.WsOutbound;
@SuppressWarnings({"deprecation","unused", "serial"}) public class WebSocketTest extends WebSocketServlet { private static List<MyMessageInbound> userList = new ArrayList<MyMessageInbound>(); private HttpSession session;
@Override protected StreamInbound createWebSocketInbound(String str, HttpServletRequest request) { session=request.getSession(); return new MyMessageInbound(); }
private class MyMessageInbound extends MessageInbound { WsOutbound myoutbound;
/** * 当用户登录时，WebSocket握手完成，创建完毕，WsOutbound用于向客户端发送数据 */ public void onOpen(WsOutbound outbound) { try { System.out.println("Open Client."); this.myoutbound = outbound; userList.add(this); //添加当前用户 //向客服端发送信息 outbound.writeTextMessage(CharBuffer.wrap("Hello!")); } catch (IOException e) { e.printStackTrace(); } }
/** * 用户退出时，WebSocket关闭事件，参数status应该来自org.apache.catalina.websocket.Constants * 中定义的几个常量，可以参考文档或者核对一下Tomcat的源码 */ @Override public void onClose(int status) { userList.remove(this); //移除当前用户 }
/** * 接受用户发过来的信息，有文本消息数据到达 */ @Override public void onTextMessage(CharBuffer cb) throws IOException { for (MyMessageInbound mmib:userList){ //循环向所有在线用户发送当前用户的信息 CharBuffer buffer = CharBuffer.wrap(cb); mmib.myoutbound.writeTextMessage(buffer); //调用指定用户的发送方法发送当前用户信息 mmib.myoutbound.flush(); //清空缓存 } }
/** * 有二进制消息数据到达，暂时没研究出这个函数什么情况下触发，js的WebSocket按理说应该只能send文本信息才对 */ @Override public void onBinaryMessage(ByteBuffer bb) throws IOException { } } }
web.xml配置文件
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns="/xml/ns/javaee" xmlns:xsi="/2001/XMLSchema-instance" xsi:schemaLocation="/xml/ns/javaee; /xml/ns/javaee/web-app_3_0.xsd"> <display-name></display-name> <servlet> <servlet-name>webServlet</servlet-name> <servlet-class>com.yc.websockets.WebSocketTest</servlet-class> </servlet> <servlet-mapping> <servlet-name>webServlet</servlet-name> <url-pattern>/webServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.html</welcome-file> </welcome-file-list> </web-app>
index.html
<!DOCTYPE html> <html> <head> <meta charset=UTF-8> <title>Tomcat WebSocket Chat</title> <script> //设定WebSocket,注意协议是ws，请求是指向对应的WebSocketServlet的 /*设定WebSocket,注意协议是ws，请求是指向对应的WebSocketServlet的 var url = "ws://127.0.0.1:8080/j2ee6/echo.ws"; // 创建WebSocket实例，下面那个MozWebSocket是Firefox的实现 if ('WebSocket' in window) { ws = new WebSocket(url); } else if ('MozWebSocket' in window) { ws = new MozWebSocket(url); } else { alert('Unsupported.'); return; }*/ var ws = new WebSocket("ws://218.196.14.208:8080/webSocket/webServlet");
//WebSocket握手完成，连接成功的回调 //有个疑问，按理说new WebSocket的时候就会开始连接了，如果在设置onopen以前连接成功，是否还会触发这个回调 ws.onopen = function() { //请求成功 };
//收到服务器发送的文本消息, event.data表示文本内容 ws.onmessage = function(message) { document.getElementById("talkInfo").innerHTML+=message.data+"<hr style='border: 1px dashed #CCC'/>"; };
//关闭WebSocket的回调 ws.onclose = function() { //alert('Closed!'); };
// 通过WebSocket想向服务器发送一个文本信息 function postToServer() { ws.send(document.getElementById("content").value); document.getElementById("content").value = ""; }
//关闭WebSocket function closeConnect() { ws.close(); } </script> <style> * { margin: 0 auto; padding: 0px; font-size: 12px; font-family: "微软雅黑"; line-height: 26px; }
#bigbox { margin:0px auto; padding:0px; width:70%; }
#talkInfo{ width:100%; height:500px; border:1px solid red; overflow: scorll; }
#operation{ width:100%; height:30px; margin-top:10px; }
#content{ height:30px; line-height:30px; } </style> </head> <body> <div id="bigbox"> <div id="talkInfo"></div> <div id="operation"> <center> <input type="text" name="content" id="content" size="100"/> <input type="button" value=" 发送 " οnclick="postToServer()" /> <input type="button" value=" 我闪 " οnclick="closeConnect()" /> </center> </div> </div> </body> </html>
