java WebSocket实现聊天消息推送功能

本文实例为大家分享了java websocket实现聊天消息推送功能的具体代码，供大家参考，具体内容如下

环境：

jdk.1.7.0_51

apache-tomcat-7.0.53

java jar包：tomcat-coyote.jar、tomcat-juli.jar、websocket-api.jar

chatannotation消息发送类：

import java.io.ioexception;
import java.util.hashmap;
import java.util.map;
import java.util.concurrent.atomic.atomicinteger;
 
import javax.websocket.onclose;
import javax.websocket.onerror;
import javax.websocket.onmessage;
import javax.websocket.onopen;
import javax.websocket.session;
import javax.websocket.server.serverendpoint;
 
import org.apache.juli.logging.log;
import org.apache.juli.logging.logfactory;
 
import com.util.htmlfilter; 
 
/**
 * websocket 消息推送服务类
 * @author 胡汉三
 *
 * 2014-11-18 下午7:53:13
 */
@serverendpoint(value = "/websocket/chat")
public class chatannotation {
 
  private static final log log = logfactory.getlog(chatannotation.class);
 
  private static final string guest_prefix = "guest";
  private static final atomicinteger connectionids = new atomicinteger(0);
  private static final map<string,object> connections = new hashmap<string,object>();
 
  private final string nickname;
  private session session;
 
  public chatannotation() {
    nickname = guest_prefix + connectionids.getandincrement();
  }
 
 
  @onopen
  public void start(session session) {
    this.session = session;
    connections.put(nickname, this); 
    string message = string.format("* %s %s", nickname, "has joined.");
    broadcast(message);
  }
 
 
  @onclose
  public void end() {
    connections.remove(this);
    string message = string.format("* %s %s",
        nickname, "has disconnected.");
    broadcast(message);
  }
 
 
  /**
   * 消息发送触发方法
   * @param message
   */
  @onmessage
  public void incoming(string message) {
    // never trust the client
    string filteredmessage = string.format("%s: %s",
        nickname, htmlfilter.filter(message.tostring()));
    broadcast(filteredmessage);
  }
 
  @onerror
  public void onerror(throwable t) throws throwable {
    log.error("chat error: " + t.tostring(), t);
  }
 
  /**
   * 消息发送方法
   * @param msg
   */
  private static void broadcast(string msg) {
   if(msg.indexof("guest0")!=-1){
   senduser(msg);
   } else{
   sendall(msg);
   }
  } 
  
  /**
   * 向所有用户发送
   * @param msg
   */
  public static void sendall(string msg){
   for (string key : connections.keyset()) {
     chatannotation client = null ;
      try {
       client = (chatannotation) connections.get(key);
        synchronized (client) {
          client.session.getbasicremote().sendtext(msg);
        }
      } catch (ioexception e) { 
        log.debug("chat error: failed to send message to client", e);
        connections.remove(client);
        try {
          client.session.close();
        } catch (ioexception e1) {
          // ignore
        }
        string message = string.format("* %s %s",
            client.nickname, "has been disconnected.");
        broadcast(message);
      }
    }
  }
  
  /**
   * 向指定用户发送消息 
   * @param msg
   */
  public static void senduser(string msg){
   chatannotation c = (chatannotation)connections.get("guest0");
 try {
  c.session.getbasicremote().sendtext(msg);
 } catch (ioexception e) {
  log.debug("chat error: failed to send message to client", e);
      connections.remove(c);
      try {
        c.session.close();
      } catch (ioexception e1) {
        // ignore
      }
      string message = string.format("* %s %s",
          c.nickname, "has been disconnected.");
      broadcast(message); 
 } 
  }
}

htmlfilter工具类：

/**
 * html 工具类 
 *
 * @author 胡汉三
 */
public final class htmlfilter {
  public static string filter(string message) {
    if (message == null)
      return (null);
    char content[] = new char[message.length()];
    message.getchars(0, message.length(), content, 0);
    stringbuilder result = new stringbuilder(content.length + 50);
    for (int i = 0; i < content.length; i++) {
      switch (content[i]) {
      case '<':
        result.append("<");
        break;
      case '>':
        result.append(">");
        break;
      case '&':
        result.append("&");
        break;
      case '"':
        result.append(""");
        break;
      default:
        result.append(content[i]);
      }
    }
    return (result.tostring());
  }
}

页面：

<%@ page language="java" import="java.util.*" pageencoding="utf-8"%>
<%
string path = request.getcontextpath();
string basepath = request.getscheme()+"://"+request.getservername()+":"+request.getserverport()+path+"/";
%>
 
<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
  <title>测试</title>
  <style type="text/css">
    input#chat {
      width: 410px
    }
 
    #console-container {
      width: 400px;
    }
 
    #console {
      border: 1px solid #cccccc;
      border-right-color: #999999;
      border-bottom-color: #999999;
      height: 170px;
      overflow-y: scroll;
      padding: 5px;
      width: 100%;
    }
 
    #console p {
      padding: 0;
      margin: 0;
    }
 </style>
  <script type="text/javascript">
 
    var chat = {};
 
    chat.socket = null;
 
    chat.connect = (function(host) {
      if ('websocket' in window) {
        chat.socket = new websocket(host);
      } else if ('mozwebsocket' in window) {
        chat.socket = new mozwebsocket(host);
      } else {
        console.log('error: websocket is not supported by this browser.');
        return;
      }
 
      chat.socket.onopen = function () {
        console.log('info: websocket connection opened.');
        document.getelementbyid('chat').onkeydown = function(event) {
          if (event.keycode == 13) {
            chat.sendmessage();
          }
        };
      };
 
      chat.socket.onclose = function () {
        document.getelementbyid('chat').onkeydown = null;
        console.log('info: websocket closed.');
      };
 
      chat.socket.onmessage = function (message) {
        console.log(message.data);
      };
    });
 
    chat.initialize = function() {
      if (window.location.protocol == 'http:') {
        chat.connect('ws://' + window.location.host + '/socket2/websocket/chat');
      } else {
        chat.connect('wss://' + window.location.host + '/socket2/websocket/chat');
      }
    };
 
    chat.sendmessage = (function() {
      var message = document.getelementbyid('chat').value;
      if (message != '') {
        chat.socket.send(message);
        document.getelementbyid('chat').value = '';
      }
    });
 
    var console = {};
 
    console.log = (function(message) {
      var console = document.getelementbyid('console');
      var p = document.createelement('p');
      p.style.wordwrap = 'break-word';
      p.innerhtml = message;
      console.appendchild(p);
      while (console.childnodes.length > 25) { 
        console.removechild(console.firstchild);
      }
      console.scrolltop = console.scrollheight;
    });
 
    chat.initialize();
 
 
    document.addeventlistener("domcontentloaded", function() {
      // remove elements with "noscript" class - <noscript> is not allowed in xhtml
      var noscripts = document.getelementsbyclassname("noscript");
      for (var i = 0; i < noscripts.length; i++) {
        noscripts[i].parentnode.removechild(noscripts[i]);
      }
    }, false);
 
  </script>
</head>
<body>
<div class="noscript"><h2 style="color: #ff0000">seems your browser doesn't support javascript! websockets rely on javascript being enabled. please enable
  javascript and reload this page!</h2></div>
<div>
  <p>
    <input type="text" placeholder="请输入内容" id="chat" />
  </p>
  <div id="console-container">
    <div id="console"/>
  </div>
</div>
</body>
</html>

可指定发送给某个用户，也可全部发送，详情见chatannotation类的broadcast方法。
程序发布时记得删除tomcat-coyote.jar、tomcat-juli.jar、websocket-api.jar这三个jar包在启动tomcat。

程序截图，guest0用户发送信息的信息，在后台进行了判断只发送给自己：

guest1：

guest2：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。