java websockect-白红宇

java websockect

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发布时间：2019-06-20

本文共 13054 字，大约阅读时间需要 43 分钟。

https://github.com/TooTallNate/Java-WebSocket (websockect类库包)

http://blog.openlg.net/index.php/archives/129（实例篇）

http://my.oschina.net/yushulx/blog/298140 (使用Jetty搭建Java Websocket Server，实现图像传输)

http://linxh83.iteye.com/blog/1466017 ()

http://findhy.com/blog/2014/06/12/java-websocket/(Java-WebSocket)

(7.0.26支持websocket)

http://java-websocket.org/ (A barebones WebSocket client and server implementation written in 100% Java.)

WebSocket 规范的目标是在浏览器中实现和服务器端双向通信。双向通信可以拓展浏览器上的应用类型，例如实时的数据推送(股票行情)、游戏、聊天等.

目前在浏览器中通过http仅能实现单向的通信,comet可以一定程度上模拟双向通信,但效率较低,并需要服务器有较好的支持; flash中的socket和xmlsocket可以实现真正的双向通信,通过 flex ajax bridge,可以在javascript中使用这两项功能. 可以预见,如果websocket一旦在浏览器中得到实现,将会替代上面两项技术,得到广泛的使用.面对这种状况，HTML5定义了WebSocket协议，能更好的节省服务器资源和带宽并达到实时通讯。

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
     
       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
      
       ();				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
       
         getWsServers() {		return wsServers;	}	public void setWsServers(Map
        
          wsServers) {		this.wsServers = wsServers;	}	}

3.接口IWSServerDispatcher.java：

package com.hisense.romeo.websocket.server;import java.util.Set;import org.java_websocket.WebSocket;/*** * 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
      
        wss, String message) 发送消息给${wss}* sendMessageToAll(String message) 发送消息给所有客户端* 
      
* @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
     
       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wss** @param wss* @param message*/public void sendMessage(Set
     
       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;/*** * 值对象* 用于WebSocket推送数据变化的进行数据刷新的值对象* 
* @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)*/@Overridepublic 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()*/@Overridepublic 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);elsemsg.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：

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