java websockect

WebSocket protocol 是HTML5一种新的协议(protocol)。它是实现了浏览器与服务器全双工通信(full-duplex)。

现在，很多网站为了实现即时通讯(real-time)，所用的技术都是轮询(polling)。轮询是在特定的的时间间隔(time interval)（如每1秒），由浏览器对服务器发出HTTP request，然后由服务器返回最新的数据给客服端的浏览器。这种传统的HTTP request d的模式带来很明显的缺点 – 浏览器需要不断的向服务器发出请求(request)，然而HTTP request 的header是非常长的，里面包含的数据可能只是一个很小的值，这样会占用很多的带宽。

而最比较新的技术去做轮询的效果是Comet – 用了AJAX。但这种技术虽然可达到全双工通信，但依然需要发出请求(reuqest)。

在 WebSocket API，浏览器和服务器只需要要做一个握手的动作，然后，浏览器和服务器之间就形成了一条快速通道。两者之间就直接可以数据互相传送。在此WebSocket 协议中，为我们实现即使服务带来了两大好处：

1. Header

互相沟通的Header是很小的-大概只有 2 Bytes

2. Server Push

服务器可以主动传送数据给客户端

明天为大家分享如何使用Java实现WebSocket Server端。

目录结构：

1.WebSocket Server服务抽象类WSServer.java:

package com.hisense.romeo.websocket.server;

/**

 *

 * WebSocket Server服务抽象类

 * 	自定义处理WebSocket客户端请求的服务：

 * 	1.继承并实现此类抽象方法

 * 	2.修改配置文件/WEB-INF/conf/spring/applicationContext-websocket.xml，给wsServerDispatcher添加处理

 * 		例如:实现一个简单的聊天室，在配置文件中添加

 * 			{@code

 *

 * 			}

 * 		当客户端请求ws://127.0.0.1:8089/chat时，系统会自动将请求分派给com.hisense.romeo.websocket.server.dispatcher.ChatWSServer处理

 * 	3.如需发送消息可以直接调用wsServerDispatcher.sendMessage方法

 *

 *

 * @see com.hisense.romeo.websocket.server.IWSServerDispatcher

 *

 * @author 	lirufei@lg	mailto:lirufei0808@gmail.com

 * @version	v0.0.1

 */

public abstract class WSServer implements IWSServer {

	/**

	 * 当前调度WebSocket请求的服务，实现者可以用它进行向客户但发送消息

	 */

	protected IWSServerDispatcher wsServerDispatcher;

	/**

	 * 注册当前WebSocket服务调度员的方法

	 *

	 * @param wsServerDispatcher

	 */

	public void registerWSServerDispatcher(IWSServerDispatcher wsServerDispatcher) {

		this.wsServerDispatcher = wsServerDispatcher;

	}

}

2.WebSocket请求调度工作WSServerDispatcher.java:

package com.hisense.romeo.websocket.server;

import java.net.InetSocketAddress;

import java.net.UnknownHostException;

import java.util.Collection;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import org.apache.log4j.Level;

import org.apache.log4j.Logger;

import org.java_websocket.WebSocket;

import org.java_websocket.WebSocketServer;

import org.java_websocket.handshake.ClientHandshake;

import org.springframework.beans.factory.DisposableBean;

import org.springframework.beans.factory.InitializingBean;

/**

 *

 * 实现WebSocket请求调度工作

 * 	根据客户端请求地址中的请求资源进行调度

 * 	例如：Address: ws://127.0.0.1:8089/chat

 * 		程序会获取address中的chat进行分发请求。

 *

 * @author 	lirufei@lg	mailto:lirufei0808@gmail.com

 * @version

 *

 */

public class WSServerDispatcher extends WebSocketServer implements IWSServerDispatcher, InitializingBean, DisposableBean{

	/**

	 * Log4j

	 */

	private Logger logger = Logger.getLogger(this.getClass());

	private Map<string, iwsserver=""> wsServers;

	private static int port = 8089;

	public WSServerDispatcher() throws UnknownHostException {

		this(new InetSocketAddress(port));

	}

	public WSServerDispatcher(InetSocketAddress address){

		super(address);

		logger.debug("default using port '" + address.getPort() + "' to startup the WebSocket Server." );

	}

	/**

	 * 建立新连接时自动调用此方法

	 *

	 * @see org.java_websocket.WebSocketServer#onOpen(org.java_websocket.WebSocket, org.java_websocket.handshake.ClientHandshake)

	 */

	@Override

	public void onOpen(WebSocket ws, ClientHandshake clientHandData) {

		ws.setHandshakedata(clientHandData);

		logger.debug("new Client:\n	" + ws.getRemoteSocketAddress() + "\n	" + clientHandData.getResourceDescriptor());

	}

	/**

	 * 当接收到新消息时调用此方法

	 *

	 * @see org.java_websocket.WebSocketServer#onMessage(org.java_websocket.WebSocket, java.lang.String)

	 */

	@Override

	public void onMessage(WebSocket ws, String message) {

		logger.debug("new Message:\n:	" + ws.getRemoteSocketAddress() + ":\n	" + message);

		String resource = getResourceDescriptor(ws);

		if(resource != null && resource.trim().length()!=0){

			IWSServer listener = wsServers.get(resource);

			if(listener != null)

				listener.onMessage(ws, message);

			else

				logger.error("请求资源" + resource + "不存在！");

		} else

			logger.error("请求资源不能为空！");

	}

	/**

	 * 连接关闭时自动调用此方法

	 *

	 * @see org.java_websocket.WebSocketServer#onClose(org.java_websocket.WebSocket, int, java.lang.String, boolean)

	 */

	@Override

	public void onClose(WebSocket ws, int arg1, String arg2, boolean arg3) {

		logger.debug("client close:\n" + ws.getRemoteSocketAddress());

	}

	/**

	 * 当连接出现错误时自动调用此方法

	 *

	 * @see org.java_websocket.WebSocketServer#onError(org.java_websocket.WebSocket, java.lang.Exception)

	 */

	@Override

	public void onError(WebSocket ws, Exception e) {

		logger.error("client error:\n" + ws.getRemoteSocketAddress() + "\n", e);

	}

	/**

	 * 根据请求资源导航串获取所有的客户端

	 *

	 * @param navigation

	 * @return

	 */

	@Override

	public Set getClientByNavigation(String navigation){

		if( navigation == null)

			return null;

		Set wss = new HashSet();

		Set conections = this.connections();

		for (WebSocket webSocket : conections) {

			String resource = this.getResourceDescriptor(webSocket);

			if(resource != null && resource.equals(navigation))

				wss.add(webSocket);

		}

		return wss;

	}

	/**

	 * 获取客户端数量

	 * @see com.hisense.romeo.websocket.server.IWSSendMessage#getClientCount(java.lang.String)

	 */

	@Override

	public int getClientCount(String name){

		Set set = this.getClientByNavigation(name);

		if(set != null)

			return set.size();

		return 0;

	}

	/**

	 * 给${navigation}的所有客户段发送消息${message}

	 *

	 * @param message

	 * @param navigation	Not Null

	 */

	public void sendMessage(String message, String navigation){

		this.sendMessage(this.getClientByNavigation(navigation), message);

	}

	/**

	 * 发送消息给所有客户端

	 *

	 * @param message

	 */

	public void sendMessageToAll(String message){

		this.sendMessage(this.connections(), message);

	}

	/**

	 * 发送消息给wss

	 *

	 * @param wss

	 * @param message

	 */

	public void sendMessage(Set wss, String message){

		if( wss != null)

			for (WebSocket webSocket : wss) {

				webSocket.send(message);

			}

	}

	/**

	 * 当服务器退出时调用此方法

	 *

	 * @see org.springframework.beans.factory.DisposableBean#destroy()

	 */

	@Override

	public void destroy() throws Exception {

		logger.info("Stop web socket server...");

		super.stop();

		if( wsServers != null && !wsServers.isEmpty()){

			Set set = wsServers.keySet();

			for (String key : set) {

				wsServers.get(key).destroy();

			}

		}

	}

	/**

	 * 当服务器启动时调用此方法

	 *

	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()

	 */

	@Override

	public void afterPropertiesSet() throws Exception {

		logger.info("**Startup web socket server，listening on port <" + port + ">.**");

		if(wsServers == null )

			wsServers = new HashMap<string, iwsserver="">();

		try {

			WebSocket.DEBUG = Logger.getLogger("com.hisense.romeo.websocket.server").getLevel().toInt() == Level.DEBUG_INT;

			this.start();

			logger.debug("**Initialization dispatchers.**");

			Collection collection = wsServers.values();

			for (IWSServer wsServerListener : collection) {

				wsServerListener.registerWSServerDispatcher(this);

			}

			logger.info("**WebSocket server has started.**");

		} catch (Exception e) {

			e.printStackTrace();

		}

	}

	/**

	 * 获取客户端webSocket请求的资源

	 *

	 * @param webSocket

	 * @return

	 */

	private String getResourceDescriptor(WebSocket webSocket){

		if(webSocket != null && webSocket.getHandshakedata() != null){

			String resource = webSocket.getHandshakedata().getResourceDescriptor();

			if(resource != null && resource.length() > 0)

				return resource.substring(1);

			else

				return resource;

		} else

			return null;

	}

	/**

	 * 设置WebSocket服务的监听端口

	 *

	 * @param port

	 */

	public void setPort(int port) {

		WSServerDispatcher.port = port;

		this.setAddress(new InetSocketAddress(port));

		logger.debug("Update port to '" + port + "' ant startup the WebSocket Server." );

	}

	public int getPort(){

		return super.getPort();

	}

	public Map<string, iwsserver=""> getWsServers() {

		return wsServers;

	}

	public void setWsServers(Map<string, iwsserver=""> wsServers) {

		this.wsServers = wsServers;

	}

}

3.接口IWSServerDispatcher.java：

package com.hisense.romeo.websocket.server;

import java.util.Set;

import org.java_websocket.WebSocket;

/**

* <pre>

* getClientByNavigation(String navigation) 根据请求资源导航串获取所有的客户端

* sendMessage(String message, String navigation) 给请求${navigation}的所有客户段发送消息${message}

* sendMessage(Set<WebSocket> wss, String message) 发送消息给${wss}

* sendMessageToAll(String message) 发送消息给所有客户端

* </pre>

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version v0.0.1

*

*/

public interface IWSServerDispatcher extends IWSSendMessage{

/**

* 根据请求资源导航串获取所有的客户端

*

* @param navigation

* @return

*/

public Set<WebSocket> getClientByNavigation(String navigation);

}

4.接口IWSServer.java：

package com.hisense.romeo.websocket.server;

import org.java_websocket.WebSocket;

/**

*

*

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version

*

*/

public interface IWSServer {

/**

* 注册当前WebSocket服务调度员的方法

*

* @param wsServerDispatcher

*/

public void registerWSServerDispatcher(IWSServerDispatcher wsServerDispatcher);

/**

* 当接收到客户端消息时，会调用这个方法

*

* @param ws 客户端信息

* @param msg 接收到的消息

*/

public abstract void onMessage(WebSocket ws, String msg);

/**

* 销毁方法，当服务器停止时调用这个方法

*/

public abstract void destroy();

}

5.接口IWSSendMessage.java：

package com.hisense.romeo.websocket.server;

import java.util.Set;

import org.java_websocket.WebSocket;

/**

* 定义使用WebSocket向客户端发送消息的方法

*

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version

*

*/

public interface IWSSendMessage {

/**

* 给请求${navigation}的所有客户段发送消息${message}

*

* @param message 要发送的消息

* @param navigation Not Null

*/

public void sendMessage(String message, String navigation);

/**

* 发送消息给<code>wss</code>

*

* @param wss

* @param message

*/

public void sendMessage(Set<WebSocket> wss, String message);

/**

* 发送消息给所有客户端

*

* @param message

*/

public void sendMessageToAll(String message);

/**

* 根据名字查询客户端数量

*

* @param name

*/

public int getClientCount(String name);

}

6.消息值对象：MessageEntity.java

package com.hisense.romeo.websocket.common;

import java.io.Serializable;

/**

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version v0.0.1

*

*/

public class MessageEntity implements Serializable{

/**

*

*/

private static final long serialVersionUID = 1L;

/**

* 用户名

*/

private String user;

/**

* 密码

*/

private String pass;

/**

* 目标模块

*/

private String target;

/**

* 消息

*/

private String message;

/**

* 是否成功

*/

private boolean success = true;

public String getUser() {

return user;

}

public void setUser(String user) {

this.user = user;

}

public String getPass() {

return pass;

}

public void setPass(String pass) {

this.pass = pass;

}

public String getTarget() {

return target;

}

public void setTarget(String target) {

this.target = target;

}

public String getMessage() {

return message;

}

public void setMessage(String message) {

this.message = message;

}

public boolean getSuccess() {

return success;

}

public void setSuccess(boolean success) {

this.success = success;

}

}

7.业务值对象：RefreshVO.java

package com.hisense.romeo.websocket.common;

/**

* <pre>

* 值对象

* 用于WebSocket推送数据变化的进行数据刷新的值对象

* </pre>

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version

*

*/

public class RefreshVO extends MessageEntity {

/**

*

*/

private static final long serialVersionUID = 1L;

/**

* 变化的表名称

*/

private String[] tables;

public String[] getTables() {

return tables;

}

public void setTables(String[] tables) {

this.tables = tables;

}

}

8.用于聊天的服务端程序ChatWSServer.java

package com.hisense.romeo.websocket.server.dispatcher;

import org.java_websocket.WebSocket;

import com.hisense.romeo.websocket.server.WSServer;

/**

* 实现简单聊天室

*

* @author lirufei@lg mailto:lirufei0808@gmail.com

* @version

*

*/

public class ChatWSServer extends WSServer{

/**

* @see com.hisense.romeo.websocket.server.IWSServer#onMessage(org.java_websocket.WebSocket, java.lang.String)

*/

@Override

public void onMessage(WebSocket ws, String msg) {

if(wsServerDispatcher != null )

wsServerDispatcher.sendMessage(ws.getRemoteSocketAddress().getHostName() + "说:" + msg, "chat");

}

/**

* @see com.hisense.romeo.websocket.server.IWSServer#destroy()

*/

@Override

public void destroy() {

}

}

9.用于发送和接收消息的客户端代码chat.js：

// Write your code in the same way as for native WebSocket:

var hostname = location.hostname,

ws = new WebSocket('ws://' + hostname + ':8089/chat'),

msg = document.getElementById('msg'),

text = document.getElementById('text'),

btn = document.getElementById('button');

setMsgValue = function(val){

msg.value = msg.value + val;

if(msg.scrollByLines)

msg.scrollByLines(5);

else

msg.scrollTop = msg.value.length;

};

ws.onopen = function() {

setMsgValue('open');

};

ws.onmessage = function(e) {

setMsgValue('\n' + e.data);

};

ws.onclose = function() {

setMsgValue('\n' + 'close');

};

btn.onclick = function(){

ws.send(text.value);

text.value='';

};

text.onkeyup = function(e){

if(/(m|M)(s|S)(i|I)(e|E)/.test(navigator.userAgent))

e = window.event;

if(e.keyCode === 13){

ws.send(text.value);

text.value='';

}

}

源码下载：http://42.96.146.196/share/ws.7z