javaweb webSocket 实现简单的点对点聊天功能

本文依据 http://redstarofsleep.iteye.com/blog/1488639?page=4 内容修改完成，实现点对点聊天

需要 jdk 7 ， tomcat需要支持websocket的版本

1.InitServlet

该类主要是用来初始化构造将来存储用户身份信息的map仓库，利用其初始化方法Init 初始化仓库， 利用其静态方法getSocketList 获得对应的用户身份信息。

webSocket ，我认为MessageInbound 用来识别登录人的信息，用它来找到对应的人，推送消息。每次登录都会产生一个MessageInbound。

这里的 HashMap<String,MessageInbound>    ：string 存储用户session的登录id,MessageInbound存储 推送需要的身份信息。以上属于个人口头话理解。

 1 package socket;  2   3 import java.nio.CharBuffer;  4 import java.util.ArrayList;  5 import java.util.HashMap;  6 import java.util.List;  7   8 import javax.servlet.ServletConfig;  9 import javax.servlet.ServletException; 10 import javax.servlet.http.HttpServlet; 11  12 import org.apache.catalina.websocket.MessageInbound; 13  14 public class InitServlet extends HttpServlet { 15  16     private static final long serialVersionUID = -3163557381361759907L;   17      18     //private static List<MessageInbound> socketList;     19     private static HashMap<String,MessageInbound> socketList;     20        21     public void init(ServletConfig config) throws ServletException {     22 //        InitServlet.socketList = new ArrayList<MessageInbound>();     23         InitServlet.socketList = new HashMap<String,MessageInbound>();     24         super.init(config);     25         System.out.println("Server start============");     26     }     27          28     public static HashMap<String,MessageInbound> getSocketList() {     29         return InitServlet.socketList;     30     }     31 /*    public static List<MessageInbound> getSocketList() {     32         return InitServlet.socketList;     33     }     34 */}

2.MyWebSocketServlet

websocket用来建立连接的servlet，建立连接时，首先在session获取该登录人的userId，在调用MyMessageInbound构造函数传入userId

 1 package socket;  2   3 import java.io.IOException;  4 import java.io.PrintWriter;  5 import java.nio.CharBuffer;  6   7 import javax.servlet.ServletException;  8 import javax.servlet.http.HttpServlet;  9 import javax.servlet.http.HttpServletRequest; 10 import javax.servlet.http.HttpServletResponse; 11  12 import org.apache.catalina.websocket.StreamInbound; 13 import org.apache.catalina.websocket.WebSocketServlet; 14 /** 15  *  16  * @ClassName: MyWebSocketServlet  17  * @Description: 建立连接时创立  18  * @author mangues 19  * @date 2015-7-19 20  */ 21 public class MyWebSocketServlet extends WebSocketServlet { 22      23     public String getUser(HttpServletRequest request){  24         String userName = (String) request.getSession().getAttribute("user"); 25         if(userName==null){ 26             return null; 27         } 28         return userName;   29        // return (String) request.getAttribute("user");   30     }   31     @Override 32     protected StreamInbound createWebSocketInbound(String arg0, 33             HttpServletRequest request) { 34         System.out.println("##########");   35         return new MyMessageInbound(this.getUser(request));  36     } 37  38 }

3.onOpen方法调用InitServlet的map身份仓库，

放入用户userId 和 对应该登录用户的websocket身份信息MessageInbound （可以用userId来寻找到推送需要的 身份MessageInbound ）

onTextMessage ：用来获取消息，并发送消息

 1 package socket;  2   3 import java.io.IOException;  4 import java.nio.ByteBuffer;  5 import java.nio.CharBuffer;  6 import java.util.HashMap;  7   8 import org.apache.catalina.websocket.MessageInbound;  9 import org.apache.catalina.websocket.WsOutbound; 10  11 import util.MessageUtil; 12  13 public class MyMessageInbound extends MessageInbound { 14  15     private String name; 16     public MyMessageInbound() { 17         super(); 18     } 19  20     public MyMessageInbound(String name) { 21         super(); 22         this.name = name; 23     } 24  25     @Override   26     protected void onBinaryMessage(ByteBuffer arg0) throws IOException {   27         // TODO Auto-generated method stub  28            29     }   30    31     @Override   32     protected void onTextMessage(CharBuffer msg) throws IOException {  33         //用户所发消息处理后的map 34         HashMap<String,String> messageMap = MessageUtil.getMessage(msg);    //处理消息类 35         //上线用户集合类map 36         HashMap<String, MessageInbound> userMsgMap = InitServlet.getSocketList(); 37          38         String fromName = messageMap.get("fromName");    //消息来自人 的userId 39          40    41         String toName = messageMap.get("toName");         //消息发往人的 userId 42         //获取该用户 43         MessageInbound messageInbound = userMsgMap.get(toName);    //在仓库中取出发往人的MessageInbound 44          45          46          47         if(messageInbound!=null){     //如果发往人 存在进行操作 48              WsOutbound outbound = messageInbound.getWsOutbound();  49               50               51              String content = messageMap.get("content");  //获取消息内容 52              String msgContentString = fromName + "     " + content;   //构造发送的消息 53               54              //发出去内容 55              CharBuffer toMsg =  CharBuffer.wrap(msgContentString.toCharArray()); 56             outbound.writeTextMessage(toMsg);  // 57             outbound.flush(); 58         } 59       60          61          62       /*  for (MessageInbound messageInbound : InitServlet.getSocketList()) {   63             CharBuffer buffer = CharBuffer.wrap(msg);   64             WsOutbound outbound = messageInbound.getWsOutbound();   65             outbound.writeTextMessage(buffer);   66             outbound.flush();   67         }  */ 68            69     }   70    71     @Override   72     protected void onClose(int status) {   73         InitServlet.getSocketList().remove(this);   74         super.onClose(status);   75     }   76    77     @Override   78     protected void onOpen(WsOutbound outbound) {   79         super.onOpen(outbound);   80         //登录的用户注册进去 81         if(name!=null){ 82             InitServlet.getSocketList().put(name, this);   83         } 84 //        InitServlet.getSocketList().add(this);   85     }   86        87        88 }

4.消息处理类，处理前端发来的消息

 1 package util;  2   3 import java.nio.CharBuffer;  4 import java.util.HashMap;  5 /**  6  *   7  * @ClassName: MessageUtil   8  * @Description: 消息处理类  9  * @author mangues 10  * @date 2015-7-19 11  */ 12 public class MessageUtil { 13  14     public static HashMap<String,String> getMessage(CharBuffer msg) { 15         HashMap<String,String> map = new HashMap<String,String>(); 16         String msgString  = msg.toString(); 17         String m[] = msgString.split(","); 18         map.put("fromName", m[0]); 19         map.put("toName", m[1]); 20         map.put("content", m[2]); 21         return map; 22     } 23 }

5.web配置

<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0"      xmlns="http://java.sun.com/xml/ns/javaee"      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">        <servlet>       <servlet-name>mywebsocket</servlet-name>       <servlet-class>socket.MyWebSocketServlet</servlet-class>     </servlet>     <servlet-mapping>       <servlet-name>mywebsocket</servlet-name>       <url-pattern>*.do</url-pattern>     </servlet-mapping>          <servlet>       <servlet-name>initServlet</servlet-name>       <servlet-class>socket.InitServlet</servlet-class>       <load-on-startup>1</load-on-startup>     </servlet>     <welcome-file-list>     <welcome-file>index.jsp</welcome-file>   </welcome-file-list> </web-app>

6,。前端，为方便起见，我直接用了两个jsp，在其中用<%session.setAttribute("user","小明")%>；来表示登录。

两个jsp没任何本质差别，只是用来表示两个不同的人登录，可以同两个浏览器打开不同的jsp，来聊天操作

A.小化

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"  2     pageEncoding="UTF-8"%>  3 <!DOCTYPE html>  4 <html>  5 <head>  6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  7 <title>Index</title>  8 <script type="text/javascript" src="js/jquery 2.1.1.min.js"></script>  9 <%session.setAttribute("user", "小化");%> 10 <script type="text/javascript"> 11 var ws = null; 12 function startWebSocket() { 13     if ('WebSocket' in window) 14         ws = new WebSocket("ws://localhost:8080/webSocket/mywebsocket.do"); 15     else if ('MozWebSocket' in window) 16         ws = new MozWebSocket("ws://localhost:8080/webSocket/mywebsocket.do"); 17     else 18         alert("not support"); 19      20      21     ws.onmessage = function(evt) { 22         //alert(evt.data); 23         console.log(evt); 24         $("#xiaoxi").val(evt.data); 25     }; 26      27     ws.onclose = function(evt) { 28         //alert("close"); 29         document.getElementById('denglu').innerHTML="离线"; 30     }; 31      32     ws.onopen = function(evt) { 33         //alert("open"); 34         document.getElementById('denglu').innerHTML="在线"; 35         document.getElementById('userName').innerHTML='小化'; 36     }; 37 } 38  39 function sendMsg() { 40     var fromName = "小化"; 41     var toName = document.getElementById('name').value;  //发给谁 42     var content = document.getElementById('writeMsg').value; //发送内容 43     ws.send(fromName+","+toName+","+content); 44 } 45 </script> 46 </head> 47 <body onload="startWebSocket();"> 48 <p>聊天功能实现</p> 49 登录状态： 50 <span id="denglu" style="color:red;">正在登录</span> 51 <br> 52 登录人： 53 <span id="userName"></span> 54 <br> 55 <br> 56 <br> 57  58 发送给谁：<input type="text" id="name" value="小明"></input> 59 <br> 60 发送内容：<input type="text" id="writeMsg"></input> 61 <br> 62 聊天框：<textarea rows="13" cols="100" readonly id="xiaoxi"></textarea> 63 <br> 64 <input type="button" value="send" onclick="sendMsg()"></input> 65 </body> 66 </html>

B.小明

<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Index</title> <script type="text/javascript" src="js/jquery 2.1.1.min.js"></script> <%session.setAttribute("user", "小明");%> <script type="text/javascript"> var ws = null; function startWebSocket() {  if ('WebSocket' in window)   ws = new WebSocket("ws://localhost:8080/webSocket/mywebsocket.do");  else if ('MozWebSocket' in window)   ws = new MozWebSocket("ws://localhost:8080/webSocket/mywebsocket.do");  else   alert("not support");  ws.onmessage = function(evt) {   console.log(evt);   //alert(evt.data);   $("#xiaoxi").val(evt.data);  };  ws.onclose = function(evt) {   //alert("close");   document.getElementById('denglu').innerHTML="离线";  };  ws.onopen = function(evt) {   //alert("open");   document.getElementById('denglu').innerHTML="在线";   document.getElementById('userName').innerHTML="小明";  }; } function sendMsg() {  var fromName = "小明";  var toName = document.getElementById('name').value;  //发给谁  var content = document.getElementById('writeMsg').value; //发送内容  ws.send(fromName+","+toName+","+content); } </script> </head> <body onload="startWebSocket();"> <p>聊天功能实现</p> 登录状态： <span id="denglu" style="color:red;">正在登录</span> <br> 登录人： <span id="userName"></span> <br> <br> <br> 发送给谁：<input type="text" id="name" value="小化"></input> <br> 发送内容：<input type="text" id="writeMsg"></input> <br> 聊天框：<textarea rows="13" cols="100" readonly id="xiaoxi"></textarea> <br> <input type="button" value="send" onclick="sendMsg()"></input> </body> </html>