使用JavaWeb webSocket实现简易的点对点聊天功能实例代码

前端技术 2023/09/07 Java

首先给大家声明一点：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。

package socket;
 import java.nio.CharBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import org.apache.catalina.websocket.MessageInbound;
 public class InitServlet extends HttpServlet {
   private static final long serialVersionUID = -L; 
   //private static List<MessageInbound> socketList;  
   private static HashMap<String,MessageInbound> socketList;  
   public void init(ServletConfig config) throws ServletException {  
 //    InitServlet.socketList = new ArrayList<MessageInbound>();  
     InitServlet.socketList = new HashMap<String,MessageInbound>();  
     super.init(config);  
     System.out.println(\"Server start============\");  
   }  
   public static HashMap<String,MessageInbound> getSocketList() {  
     return InitServlet.socketList;  
   }  
 /*  public static List<MessageInbound> getSocketList() {  
     return InitServlet.socketList;  
   }  
 */}

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

package socket;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.nio.CharBuffer;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.apache.catalina.websocket.StreamInbound;
 import org.apache.catalina.websocket.WebSocketServlet;
 /**
 * 
 * @ClassName: MyWebSocketServlet 
 * @Description: 建立连接时创立 
 * @author mangues
 * @date --
 */
 public class MyWebSocketServlet extends WebSocketServlet {
   public String getUser(HttpServletRequest request){ 
     String userName = (String) request.getSession().getAttribute(\"user\");
     if(userName==null){
       return null;
     }
     return userName; 
    // return (String) request.getAttribute(\"user\"); 
   } 
   @Override
   protected StreamInbound createWebSocketInbound(String arg,
       HttpServletRequest request) {
     System.out.println(\"##########\"); 
     return new MyMessageInbound(this.getUser(request)); 
   }
 }

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

package socket;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.CharBuffer;
 import java.util.HashMap;
 import org.apache.catalina.websocket.MessageInbound;
 import org.apache.catalina.websocket.WsOutbound;
 import util.MessageUtil;
 public class MyMessageInbound extends MessageInbound {
   private String name;
   public MyMessageInbound() {
     super();
   }
   public MyMessageInbound(String name) {
     super();
     this.name = name;
   }
   @Override 
   protected void onBinaryMessage(ByteBuffer arg) throws IOException { 
     // TODO Auto-generated method stub 
   } 
   @Override 
   protected void onTextMessage(CharBuffer msg) throws IOException { 
     //用户所发消息处理后的map
     HashMap<String,String> messageMap = MessageUtil.getMessage(msg);  //处理消息类
     //上线用户集合类map
     HashMap<String, MessageInbound> userMsgMap = InitServlet.getSocketList();
     String fromName = messageMap.get(\"fromName\");  //消息来自人 的userId
     String toName = messageMap.get(\"toName\");     //消息发往人的 userId
     //获取该用户
     MessageInbound messageInbound = userMsgMap.get(toName);  //在仓库中取出发往人的MessageInbound
     if(messageInbound!=null){   //如果发往人 存在进行操作
       WsOutbound outbound = messageInbound.getWsOutbound(); 
       String content = messageMap.get(\"content\"); //获取消息内容
       String msgContentString = fromName + \"   \" + content;  //构造发送的消息
       //发出去内容
       CharBuffer toMsg = CharBuffer.wrap(msgContentString.toCharArray());
       outbound.writeTextMessage(toMsg); //
       outbound.flush();
     }
    /* for (MessageInbound messageInbound : InitServlet.getSocketList()) { 
       CharBuffer buffer = CharBuffer.wrap(msg); 
       WsOutbound outbound = messageInbound.getWsOutbound(); 
       outbound.writeTextMessage(buffer); 
       outbound.flush(); 
     } */
   } 
   @Override 
   protected void onClose(int status) { 
     InitServlet.getSocketList().remove(this); 
     super.onClose(status); 
   } 
   @Override 
   protected void onOpen(WsOutbound outbound) { 
     super.onOpen(outbound); 
     //登录的用户注册进去
     if(name!=null){
       InitServlet.getSocketList().put(name, this); 
     }
 //    InitServlet.getSocketList().add(this); 
   } 
 }

4.消息处理类，处理前端发来的消息

 package util;
 import java.nio.CharBuffer;
 import java.util.HashMap;
 /**
  * 
  * @ClassName: MessageUtil 
  * @Description: 消息处理类
  * @author mangues
 * @date --
 */
 public class MessageUtil {
   public static HashMap<String,String> getMessage(CharBuffer msg) {
     HashMap<String,String> map = new HashMap<String,String>();
     String msgString = msg.toString();
     String m[] = msgString.split(\",\");
     map.put(\"fromName\", m[]);
     map.put(\"toName\", m[]);
     map.put(\"content\", m[]);
     return map;
   }
 }

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

<%@ page language=\"java\" contentType=\"text/html; charset=UTF-\"
   pageEncoding=\"UTF-\"%>
 <!DOCTYPE html>
 <html>
 <head>
 <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-\">
 <title>Index</title>
 <script type=\"text/javascript\" src=\"js/jquery ...min.js\"></script>
 <%session.setAttribute(\"user\", \"小化\");%>
 <script type=\"text/javascript\">
 var ws = null;
 function startWebSocket() {
   if (\'WebSocket\' in window)
     ws = new WebSocket(\"ws://localhost:/webSocket/mywebsocket.do\");
   else if (\'MozWebSocket\' in window)
     ws = new MozWebSocket(\"ws://localhost:/webSocket/mywebsocket.do\");
   else
     alert(\"not support\");
   ws.onmessage = function(evt) {
     //alert(evt.data);
     console.log(evt);
     $(\"#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=\'小化\';
   };
 }
 function sendMsg() {
   var fromName = \"小化\";
   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=\"小明\"></input>
 <br>
 发送内容：<input type=\"text\" id=\"writeMsg\"></input>
 <br>
 聊天框：<textarea rows=\"\" cols=\"\" readonly id=\"xiaoxi\"></textarea>
 <br>
 <input type=\"button\" value=\"send\" onclick=\"sendMsg()\"></input>
 </body>
 </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>

以上所述是小编给大家介绍的使用JavaWeb webSocket实现简易的点对点聊天功能实例代码的相关知识，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对phpstudy网站的支持！

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