android ftp 服务器

源码地址：http://ppareit.github.com/swiftp/   git clone git://github.com/ppareit/swiftp

1、获取手机的wifi 地址作为 ftp 服务器的地址

public static InetAddress getWifiIp()
    {
        Context myContext = Globals.getContext();
        if (myContext == null)
        {
            throw new NullPointerException("Global context is null");
        }
        WifiManager wifiMgr = (WifiManager) myContext.getSystemService(Context.WIFI_SERVICE);
        if (isWifiEnabled())
        {
            int ipAsInt = wifiMgr.getConnectionInfo().getIpAddress();
            if (ipAsInt == 0)
            {
                return null;
            }
            else
            {
                return Util.intToInet(ipAsInt);
            }
        }
        else
        {
            return null;
        }
    }

    public static boolean isWifiEnabled()
    {
        Context myContext = Globals.getContext();
        if (myContext == null)
        {
            throw new NullPointerException("Global context is null");
        }
        WifiManager wifiMgr = (WifiManager) myContext.getSystemService(Context.WIFI_SERVICE);
        if (wifiMgr.getWifiState() == WifiManager.WIFI_STATE_ENABLED)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

2、创建服务器套接字 listenSocket, 端口号可以自定义

        listenSocket = new ServerSocket();
        listenSocket.setReuseAddress(true);
        listenSocket.bind(new InetSocketAddress(port));

3、用子线程TcpListener封装 listenSocket

while (!shouldExit)
        {
            if (acceptWifi)
            {
                if (wifiListener != null)
                {
                    if (!wifiListener.isAlive())
                    {
                        myLog.l(Log.DEBUG, "Joining crashed wifiListener thread");
                        try
                        {
                            wifiListener.join();
                        }
                        catch (InterruptedException e)
                        {
                        }
                        wifiListener = null;
                    }
                }
                if (wifiListener == null)
                {
                    // Either our wifi listener hasn't been created yet, or has
                    // crashed,
                    // so spawn it
                    wifiListener = new TcpListener(listenSocket, this);
                    wifiListener.start();
                }
            }
}

4、listensocket 在TcpListener 线程的run 方法中循环监听客户端请求，并且将建立链接的clientSocket 封装到会话线程

public void run()
    {
        try
        {
            while (true)
            {

                Socket clientSocket = listenSocket.accept();
                myLog.l(Log.INFO, "New connection, spawned thread");
                SessionThread newSession = new SessionThread(clientSocket, new NormalDataSocketFactory(), SessionThread.Source.LOCAL);
                newSession.start();
                ftpServerService.registerSessionThread(newSession);
            }
        }
        catch (Exception e)
        {
            myLog.l(Log.DEBUG, "Exception in TcpListener");
        }
    }

5、在会话进程的run方法中循环处理客户端都请求

public void run()
    {
        try
        {
            BufferedReader in = new BufferedReader(new InputStreamReader(cmdSocket.getInputStream()), 8192);
            while (true)
            {
                String line;
                line = in.readLine(); // will accept \r\n or \n for terminator
                if (line != null)
                {
                    FTPServerService.writeMonitor(true, line);
                    myLog.l(Log.DEBUG, "Received line from client: " + line);
                    FtpCmd.dispatchCommand(this, line);
                }
                else
                {
                    myLog.i("readLine gave null, quitting");
                    break;
                }
            }
        }
        catch (IOException e)
        {
            myLog.l(Log.INFO, "Connection was dropped");
        }
        closeSocket();
    }

6、FtpCmd是所有命令类的父抽象类，在dispatchCommand方法中根据输入流中的参数判断命令类型，然后执行对应的命令