Android|Android 关于WebSocket的应用 Android关于WebSocket的应用

关于WebSocket，个人理解是一种网络协议，好比http,好处在于可以建立一条服务器与客户端长久的连接，从而减少每次通信都需重新建立连接而产生的损耗；缺点在于如果客户端是智能设备，当处于休眠状态时，会自动关闭网络（未测试），还有长链接的流量大小（未测试）。用途多在于即时通信，网上聊天室等。websocket 简介：http://www.html5rocks.com/zh/tutorials/websockets/basics/

【Android|Android 关于WebSocket的应用】服务端是用tomcat7,该版本已支持websocket，很方便。注意7.0.38之前版本会出现长链接自动断开，之后的版本修复了这个问题，我当前的版本是7.0.42.

@WebServlet("/sosWebSocketService") //服务名称 public class TestWebSocketServlet extends WebSocketServlet{ private final Map map = new HashMap(); //注册客户端 /** * */ private static final long serialVersionUID = -1058445282919079067L; @Override protected StreamInbound createWebSocketInbound(String arg0, HttpServletRequest req) { return new ChatMessageInbound(req.getParameter("userCode")); }class ChatMessageInbound extends MessageInbound { private String key = ""; public ChatMessageInbound(String key) { this.key = key; } @Override protected void onOpen(WsOutbound outbound) { map.put(key, outbound); super.onOpen(outbound); }@Override protected void onClose(int status) { map.remove(key); super.onClose(status); }@Override protected void onBinaryMessage(ByteBuffer buffer) throws IOException { // TODO Auto-generated method stub}@Override protected void onTextMessage(CharBuffer buffer) throws IOException { String msg = buffer.toString(); //接受客户端消息 broadcast(msg); }private void broadcast(String msg) { Set set = map.keySet(); for (String integer : set) { WsOutbound outbound = map.get(integer); CharBuffer buffer = CharBuffer.wrap(msg); try { outbound.writeTextMessage(buffer); //向客户端发送消息 outbound.flush(); } catch (IOException e) { e.printStackTrace(); } } } }}

android端：autobahn 官网： http://autobahn.ws/ 里面有详细说明，还有测试demo下载。我用了service的机制去实现，即时退出应用，服务仍可在后台运行，给出的代码去掉了次要的部分。

public class SosWebSocketClientService extends Service{ private final String TAG = "SosWebSocketClientService"; private final WebSocketConnection mConnection = new WebSocketConnection(); SharedPreferencesUtil spu; private final IBinder mBinder = new SosWebSocketClientBinder(); @Override public IBinder onBind(Intent intent) { return mBinder; } @Override public void onCreate() { spu = new SharedPreferencesUtil(SosWebSocketClientService.this, SharedPreferencesUtil.STR_XMLFILE); mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); initWebSocket(); super.onCreate(); Log.d(TAG, "Service Create"); } @Override public int onStartCommand(Intent intent, int flags, int startId) { return START_STICKY; } /** * 销毁 */ @Override public void onDestroy() { if (mConnection.isConnected()) { mConnection.disconnect(); } super.onDestroy(); Log.d(TAG, "Service Destroy"); } private void initWebSocket(){ //注意连接和服务名称要一致 /*final String wsuri = "ws://192.168.0.2：8080/st/sosWebSocketService?userCode=" + spu.getValue(LoginActivity.STR_USERNAME); */ Log.d(TAG, Config.getSosWebSocketUrl() + "/userCode=" + spu.getValue(SharedPreferencesUtil.STR_USERCODE)); final String wsuri = Config.getSosWebSocketUrl() + "?userCode=" + spu.getValue(SharedPreferencesUtil.STR_USERCODE); try { mConnection.connect(wsuri, new WebSocketHandler() { @Override public void onOpen() { Log.i(TAG, "WebSocket open"); }@Override public void onTextMessage(String text) { Log.i(TAG, "onTextMessage"); showNotification(text); }@Override public void onClose(int code, String reason) { Log.i(TAG, "Connection lost."); /*alert("Connection lost."); */} }); } catch (WebSocketException e) { Log.d(TAG, e.toString()); } } public class SosWebSocketClientBinder extends Binder { public SosWebSocketClientService getService() { return SosWebSocketClientService.this; }public void sendXxx(String addr){ if(mConnection.isConnected()) mConnection.sendTextMessage("xxx"); } }}