java WebSocket 简易聊天消息推送

分类：
HTML5WebSocket2014-11-18 20:021946人阅读评论(4)收藏举报
webSocket消息推送聊天

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：

[java]
view plaincopyprint?





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);
}
}
}

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：

[java]
view plaincopyprint?





/**
* 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());
}
}

/**
 * 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：

[html]
view plaincopyprint?





<%@ 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>

<%@ 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：