java websocket简易聊天推送

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
* 
*
*
*/ 
@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);   
        }  
    } 
}



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>