java websocket时时通信

 基本案例是网上爬的，改了很多，单纯发文字聊天功能完整， 1对1单聊， 离线用户能接受到另一方的留言，增加了一张数据库表,如果不用表保存离线数据，也可以选择单例模式缓存来保存。测试了下还可以哦！直接贴代码不明白的可以问我。

   

   java服务端:

          

package websockets;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang.time.DateFormatUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.springframework.http.server.ServletServerHttpRequest;

import  Helper.AAAAYulebaoShareSingleton;
import  Helper.MySqlHepler2;
import  Helper.EncryptSafa;

import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
 
 //auth:liaohang
@ServerEndpoint("/javaWebSocket")
public class javaWebSocket {
     //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
     private static int onlineCount = 0;
 
      //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。若要实现服务端与单一客户端通信的话，可以使用Map来存放，其中Key可以为用户标识
  //   private static CopyOnWriteArraySet<javaWebSocket> webSocketSets = new CopyOnWriteArraySet<javaWebSocket>();
     private static JSONObject  webSocketSets = new JSONObject();
      //与某个客户端的连接会话，需要通过它来给客户端发送数据
     private Session session;
     private String[] parameterArr;
     
     private String shareStr;
     private String userKey;
     private String shopKey;
     private String type;
     
     
 
     //这里来个请求的httpRequest类
     /**
       * 连接建立成功调用的方法
      * @param session  可选的参数。session为与某个客户端的连接会话，需要通过它来给客户端发送数据
      */
     

     private javaWebSocket chatmemeber;
     
     //数据库操作参数
  private   MySqlHepler2  helper=new MySqlHepler2();
  private JSONArray  returnJsonArray;
  private       String[] mysqlParameter=null;
  private JSONObject  shareObject;
  private String  datatime;
  private int shareInt=0;
 
     @OnOpen
     public void onOpen(Session session){
          this.session = session;
          shareStr= session.getRequestURI().toString();
          shareStr=shareStr.replace("/yulebaoServlet/javaWebSocket?", "");
          
       
       
          shareStr=shareStr.replace("user=", "");
          shareStr=shareStr.replace("shop=", "");
          shareStr=shareStr.replace("type=", "");
          parameterArr=shareStr.split("&");
          
          
          
          
          type=parameterArr[2];
          if(type.equals("user"))
          {
              userKey=parameterArr[0];
              shopKey=parameterArr[1];
              webSocketSets.put(userKey, this); 
              //查询一次数据库,看是有人在我离线时给我发了消息
                mysqlParameter=new String[]{userKey};   
                 returnJsonArray=helper.executeQueryT("select * from AAAAAAAAAChatSheet where  sessionKey=?", mysqlParameter);  
                 try
                 { 
                     shareInt=returnJsonArray.length();
                 } catch (Exception e) {
                     shareInt=0;
                  }
                 
                 if(returnJsonArray.length()>0)
                 {
                     shareObject=returnJsonArray.getJSONObject(0);
                     shareStr= shareObject.getString("chatContentArray");
                      try {
                        this.sendMessage(shareStr);
                    } catch (IOException e) {
                      e.printStackTrace();
                    }
                      
                  mysqlParameter=new String[]{userKey};  
                       helper.executeUpdate("delete from   AAAAAAAAAChatSheet     where sessionKey=?", mysqlParameter);
                 }
                  
                
                 
          }
          else
          {
              userKey=parameterArr[0];
              shopKey=parameterArr[1];
              webSocketSets.put(shopKey, this); 
              //查询一次数据库,看是有人在我离线时给我发了消息
               mysqlParameter=new String[]{shopKey}; 
              returnJsonArray=helper.executeQueryT("select * from AAAAAAAAAChatSheet where  sessionKey=?", mysqlParameter);  
              try
              { 
                  shareInt=returnJsonArray.length();
              } catch (Exception e) {
                  shareInt=0;
               }
              
              if(returnJsonArray.length()>0)
              {
                  shareObject=returnJsonArray.getJSONObject(0);
                 shareStr= shareObject.getString("chatContentArray");
                   try {
                      this.sendMessage(shareStr);
                    } catch (IOException e) {
                      e.printStackTrace();
                    }
                   //删除key
              
                 mysqlParameter=new String[]{shopKey};  
                 helper.executeUpdate("delete from   AAAAAAAAAChatSheet     where sessionKey=?", mysqlParameter);
              }
              
              
              
              
          }
         
          
           
           
            //加入set中
         addOnlineCount();           //在线数加1
         System.out.println("有新连接加入！当前在线人数为" + getOnlineCount());
     } 
  
  
     /**
      * 连接关闭调用的方法
      */
     @OnClose
      public void onClose(){
         if(type.equals("user"))
         {
           if(!webSocketSets.isNull(userKey))   
              {
           webSocketSets.remove(userKey); 
            }
        
         }
         else
         {
             if(!webSocketSets.isNull(shopKey))
                {
                 webSocketSets.remove(shopKey); 
                }
             
     
         }
         //从set中删除
         subOnlineCount();           //在线数减1
         System.out.println("有一连接关闭！当前在线人数为" + getOnlineCount());
     }
 
      /**
       * 收到客户端消息后调用的方法
      * @param message 客户端发送过来的消息
      * @param session 可选的参数
      */
      @OnMessage
      public void onMessage(String message, Session session) {
          System.out.println("来自客户端的消息:" + message);
          //群发消息
          if(type.equals("user"))
          {
              if(!webSocketSets.isNull(shopKey))   
                {
              chatmemeber=(javaWebSocket)webSocketSets.get(shopKey);
                try {
                  chatmemeber.sendMessage(message);
                 } catch (IOException e) {
                   e.printStackTrace();
                  }
                }
              else
              {
                  
                  insertDataBase(shopKey,message);
                 
                    
              
              }
          }
           else
           {
               if(!webSocketSets.isNull(userKey))   
                {
               chatmemeber=(javaWebSocket)webSocketSets.get(userKey);
               
              try {
                 chatmemeber.sendMessage(message);
              } catch (IOException e) {
                  e.printStackTrace();
               }
                }
               
               else
               {
                   //接消息以方不在，插入数据库保存
                  insertDataBase(userKey,message);
                 
               }
               
               
           }
         
          
         
          //1对多发消息
        /* for(javaWebSocket item: webSocketSets){
              try {
                 item.sendMessage(message);
              } catch (IOException e) {
                  e.printStackTrace();
                  continue;
             }
         }*/
      }
 
     /**
      * 发生错误时调用
      * @param session
      * @param error
      */
     @OnError
     public void onError(Session session, Throwable error){
          System.out.println("发生错误");
         error.printStackTrace();
     }
 
     /**
       * 这个方法与上面几个方法不一样。没有用注解，是根据自己需要添加的方法。
      * @param message
       * @throws IOException
      */
      public void sendMessage(String message) throws IOException{
         this.session.getBasicRemote().sendText(message);
          //this.session.getAsyncRemote().sendText(message);
      }
 
     public static synchronized int getOnlineCount() {
          return onlineCount;
      }
 
      public static synchronized void addOnlineCount() {
          javaWebSocket.onlineCount++;
     }
 
      public static synchronized void subOnlineCount() {
          javaWebSocket.onlineCount--;
     }
      
      
      
      //当一方用户下线之后，如果再发消息，需要将接收消息保存到数据库
      public void insertDataBase(String shareKey,String message)
      {
          shareObject=new JSONObject();
           datatime=DateFormatUtils.format(new Date(), "yyyy-MM-dd HH:mm");
          shareObject.put("datatime", datatime);
          shareObject.put("message", message);
          
          
         mysqlParameter=new String[]{shareKey};   
         returnJsonArray=helper.executeQueryT("select * from AAAAAAAAAChatSheet where  sessionKey=?", mysqlParameter);    
        try
        {
            shareInt=returnJsonArray.length();
        }
        catch(Exception e)
        {
            shareInt=0;
            returnJsonArray=new JSONArray();
         }
        
        
        if(shareInt==0) //插入数据
        {
        
         returnJsonArray.put(shareObject);
         mysqlParameter=new String[]{shareKey,datatime,returnJsonArray.toString()};  
         helper.executeUpdate("insert into AAAAAAAAAChatSheet(sessionKey,sessionCreateTimes,chatContentArray)values(?,?,?)", mysqlParameter);
        
        }
        else//更新连端的数据
        {
            returnJsonArray.put(shareObject);
            mysqlParameter=new String[]{returnJsonArray.toString(),shareKey};  
           helper.executeUpdate("update  AAAAAAAAAChatSheet set chatContentArray=? where sessionKey=?", mysqlParameter);
            
        }
        
           
      }
 }

  前端页面User方:

  

<%@ page language="java" pageEncoding="UTF-8" %>
  <!DOCTYPE html>
  <html>
  <head>
      <title>Java后端WebSocket的Tomcat实现</title>
  </head>
  <body>
      Welcome<br/><input id="text" type="text"/>
      <button onclick="send()">发送消息</button>
     <hr/>
     <button onclick="closeWebSocket()">关闭WebSocket连接</button>
     <hr/>
     <div id="message"></div>
 </body>
 
 <script type="text/javascript">
     var websocket = null;
     //判断当前浏览器是否支持WebSocket
     if ('WebSocket' in window) {
           //第一个创建链接的用户需要两个key,创建一个webosckt链接。为了保证JSONObject单个创建的websocket key唯一 所以参数就用双方的唯一账户或id正反组合+类型'
           //为什么要传两个key?比如这个是user请求的链接，他创建websocket时需要查询一下对方有没有离线留言,如果有离线留言得访问一次数据库读出来返回，所以shop这个key也必须带上
          var user="liaohang"+"xiaoming"+"user";
          var  shop="xiaoming"+"liaohang"+"shop";
         websocket = new WebSocket("ws://localhost:8080/yulebaoServlet/javaWebSocket?user="+user+"&shop="+shop+"&type=user");
       
     }
     else {
         alert('当前浏览器 Not support websocket')
     }
 
     //连接发生错误的回调方法
     websocket.onerror = function () {
         setMessageInnerHTML("WebSocket连接发生错误");
     };
 
     //连接成功建立的回调方法
     websocket.onopen = function () {
         setMessageInnerHTML("WebSocket连接成功");
     }
 
     //接收到消息的回调方法
     websocket.onmessage = function (event) {
         setMessageInnerHTML(event.data);
     }
 
     //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();  
        }

     //将消息显示在网页上
     function setMessageInnerHTML(innerHTML) {
         document.getElementById('message').innerHTML += innerHTML + '<br/>';
     }
 
     //关闭WebSocket连接
     function closeWebSocket() {
        websocket.close();
     }
 
     //发送消息
    function send() {
        var message = document.getElementById('text').value;
         websocket.send(message);
      }
  </script>
  </html>

前端页面Shop方:

<%@ page language="java" pageEncoding="UTF-8" %>
  <!DOCTYPE html>
  <html>
  <head>
      <title>Java后端WebSocket的Tomcat实现</title>
  </head>
  <body>
      Welcome<br/><input id="text" type="text"/>
      <button onclick="send()">发送消息</button>
     <hr/>
     <button onclick="closeWebSocket()">关闭WebSocket连接</button>
     <hr/>
     <div id="message"></div>
 </body>
 
 <script type="text/javascript">
     var websocket = null;
     //判断当前浏览器是否支持WebSocket
     if ('WebSocket' in window) {
    	  //Id account+对方的account      +type  接单者发起请求
    	  var user="liaohang"+"xiaoming"+"user";
    	  var  shop="xiaoming"+"liaohang"+"shop";
         websocket = new WebSocket("ws://localhost:8080/yulebaoServlet/javaWebSocket?user="+user+"&shop="+shop+"&type=shop");
       
     }
     else {
         alert('当前浏览器 Not support websocket')
     }
 
     //连接发生错误的回调方法
     websocket.onerror = function () {
         setMessageInnerHTML("WebSocket连接发生错误");
     };
 
     //连接成功建立的回调方法
     websocket.onopen = function () {
         setMessageInnerHTML("WebSocket连接成功");
     }
 
     //接收到消息的回调方法
     websocket.onmessage = function (event) {
         setMessageInnerHTML(event.data);
     }
 
     //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();  
        }

     //将消息显示在网页上
     function setMessageInnerHTML(innerHTML) {
         document.getElementById('message').innerHTML += innerHTML + '<br/>';
     }
 
     //关闭WebSocket连接
     function closeWebSocket() {
        websocket.close();
     }
 
     //发送消息
    function send() {
        var message = document.getElementById('text').value;
         websocket.send(message);
      }
  </script>
  </html>

  前端页面User方和 Shop方 不同的就是传参数的类型

https://www.bai6du.com/yulebaoServlet/talkTest.jsp

https://www.bai6du.com/yulebaoServlet/talkTest2.jsp