蓝牙文件传输Android

Question

我在通过蓝牙套接字发送大文件时遇到问题。较小的文件得到正确传输。我相信高达161280字节得到正确传输。

编辑：我做了一些更多的测试，并缩小了原因。看来，

outStream.write(mybytearray, 0, mybytearray.length); 

在发送代码部分是写不超过161280字节。我通过不关闭套接字连接来看到这种行为，从而导致接收部分中的read在161280字节上“阻塞”。这里的蓝牙输出流有什么问题？我究竟做错了什么？

编辑2： 这样做可以让它通过。

for(int i = 0 ; i < mybytearray.length ; i++){ 
    outStream.write(mybytearray[i]); 
} 

发送代码：

try { 
     outStream = mBluetoothSocket.getOutputStream(); 
     Log.d(TAG,"outStream created success!"); 
    } catch (IOException e) { 
     Log.d(TAG, 
       "ON RESUME: Output stream creation failed.", 
       e); 
    } 

    File myFile = new File(file_name); 
    Log.d(TAG,"file /source.pdf created success!"); 

    byte[] mybytearray = new byte[(int)myFile.length()]; 
    Log.d(TAG,"file length() =" + (int)myFile.length()); 

    FileInputStream fis = new FileInputStream(myFile); 
    Log.d(TAG,"fis created"); 

    BufferedInputStream bis = new BufferedInputStream(fis,1272254); 
    Log.d(TAG,"bis created success"); 

    bis.read(mybytearray,0,mybytearray.length); 
    Log.d(TAG,"ALL Bytes read from bis"); 

    outStream.write(mybytearray, 0, mybytearray.length); 
    Log.d(TAG,"BYTES WRITTEN to OUTSTREAM of socket"); 


    outStream.flush(); 
    Log.d(TAG,"bytes flushed"); 
    outStream.close(); 

接收代码：

// Attach the i/p stream to the socket 
    try { 
     InputStream in = socket.getInputStream(); 
     mIn = in; 
     Log.d(TAG, "input stream acquired"); 

    } catch (IOException e1) { 
     e1.printStackTrace(); 
    } 
    // Create output streams & write to file 
    FileOutputStream fos = new FileOutputStream(
      Environment.getExternalStorageDirectory() 
        + "/copy.pdf"); 
    try { 
     bytesRead = mIn.read(buffer, 0, buffer.length); 
     Log.d(TAG, "bytesRead first time =" + bytesRead); 
     current = bytesRead; 

     do { 
      Log.d(TAG, "do-while -- current: " + current); 
      bytesRead = mIn.read(buffer, current, 
        buffer.length - current); 
      Log.d(TAG, "bytesRead: =" + bytesRead); 

      if (bytesRead >= 0) 
       current += bytesRead; 
     } while (bytesRead > -1); 
    } catch (IOException e) { 
     e.printStackTrace(); 
     Log.d(TAG, "do while end:-- buffer len= " 
       + buffer.length + " current: " + current); 

     fos.write(buffer); 
     Log.d(TAG, "fos.write success! buffer: " 
       + buffer.length + " current: " + current); 

     fos.flush(); 
     fos.close(); 
    } 
} 
socket.close(); 

logcat的：

D/ReceiveService(5761): do-while -- current: 155232 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 156240 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 157248 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 158256 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 159264 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 160272 
D/ReceiveService(5761): bytesRead: =1008 
D/ReceiveService(5761): do-while -- current: 161280 
W/System.err(5761): java.io.IOException: Software caused connection abort 
W/System.err(5761): at android.bluetooth.BluetoothSocket.readNative(Native Method) 
W/System.err(5761): at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:307) 
W/System.err(5761): at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:96) 
W/System.err(5761): at com.bt.server.ReceiveService$AcceptThread.run(ReceiveService.java:141) 

我正在使用摩托罗拉Milestone。 Android 2.1

Answer 1

我能够通过向蓝牙输出发送小块数据来解决这个问题。事实证明，8 * 1024是一个很好的缓冲区大小，这有助于在数据流中无缝发送数据，并防止接收端数据损坏。

BufferedInputStream bis = new BufferedInputStream(fis, 8 * 1024); 


byte[] buffer = new byte[8192]; 
int len 
while ((len = bis.read(buffer)) != -1) { 
    outStream.write(buffer, 0, len); 
}