Android 实现无网络传输文件（1）

至此服务器端和客户端已经通过 Wifi P2P 连接在了一起，客户端也获取到了服务器端的IP地址，在选取好待发送的文件后就可以主动发起对服务器端的连接请求了
发起选取文件的方法

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*
public class WifiClientTask extends AsyncTask {

    private ProgressDialog progressDialog;

    private FileTransfer fileTransfer;

    private static final int PORT = 4786;

    private static final String TAG = "WifiClientTask";

    public WifiClientTask(Context context, FileTransfer fileTransfer) {
 this.fileTransfer = fileTransfer;
 progressDialog = new ProgressDialog(context);
 progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
 progressDialog.setCancelable(false);
 progressDialog.setCanceledOnTouchOutside(false);
 progressDialog.setTitle("正在发送文件");
 progressDialog.setMax(100);
    }

    @Override
    protected void onPreExecute() {
 progressDialog.show();
    }

    @Override
    protected Boolean doInBackground(String... strings) {
 fileTransfer.setMd5(Md5Util.getMd5(new File(fileTransfer.getFilePath())));
 Log.e(TAG, "文件的MD5码值是：" + fileTransfer.getMd5());
 Socket socket = null;
 OutputStream outputStream = null;
 ObjectOutputStream objectOutputStream = null;
 InputStream inputStream = null;
 try {
     socket = new Socket();
     socket.bind(null);
     socket.connect((new InetSocketAddress(strings[0], PORT)), 10000);
     outputStream = socket.getOutputStream();
     objectOutputStream = new ObjectOutputStream(outputStream);
     objectOutputStream.writeObject(fileTransfer);
     inputStream = new FileInputStream(new File(fileTransfer.getFilePath()));
     long fileSize = fileTransfer.getFileLength();
     long total = 0;
     byte buf[] = new byte[512];
     int len;
     while ((len = inputStream.read(buf)) != -1) {
  outputStream.write(buf, 0, len);
  total += len;
  int progress = (int) ((total * 100) / fileSize);
  publishProgress(progress);
  Log.e(TAG, "文件发送进度：" + progress);
     }
     outputStream.close();
     objectOutputStream.close();
     inputStream.close();
     socket.close();
     outputStream = null;
     objectOutputStream = null;
     inputStream = null;
     socket = null;
     Log.e(TAG, "文件发送成功");
     return true;
 } catch (Exception e) {
     Log.e(TAG, "文件发送异常 Exception: " + e.getMessage());
 } finally {
     if (outputStream != null) {
  try {
      outputStream.close();
  } catch (IOException e) {
      e.printStackTrace();
  }
     }
     if (objectOutputStream != null) {
  try {
      objectOutputStream.close();
  } catch (IOException e) {
      e.printStackTrace();
  }
     }
     if (inputStream != null) {
  try {
      inputStream.close();
  } catch (IOException e) {
      e.printStackTrace();
  }
     }
     if (socket != null) {
  try {
      socket.close();
  } catch (Exception e) {
      e.printStackTrace();
  }
     }
 }
 return false;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
 progressDialog.setProgress(values[0]);
    }

    @Override
    protected void onPostExecute(Boolean aBoolean) {
 progressDialog.cancel();
 Log.e(TAG, "onPostExecute: " + aBoolean);
    }

}

public class Md5Util {

    public static String getMd5(File file) {
 InputStream inputStream = null;
 byte[] buffer = new byte[2048];
 int numRead;
 MessageDigest md5;
 try {
     inputStream = new FileInputStream(file);
     md5 = MessageDigest.getInstance("MD5");
     while ((numRead = inputStream.read(buffer)) > 0) {
  md5.update(buffer, 0, numRead);
     }
     inputStream.close();
     inputStream = null;
     return md5ToString(md5.digest());
 } catch (Exception e) {
     return null;
 } finally {
     if (inputStream != null) {
  try {
      inputStream.close();
  } catch (IOException e) {
      e.printStackTrace();
  }
     }
 }
    }

    private static String md5ToString(byte[] md5Bytes) {
 StringBuilder hexValue = new StringBuilder();
 for (byte b : md5Bytes) {
     int val = ((int) b) & 0xff;
     if (val < 16) {
  hexValue.append("0");
     }
     hexValue.append(Integer.toHexString(val));
 }
 return hexValue.toString();
    }

}