我正在尝试开发一个Android应用程序，将图像从一个设备传输到另一个设备。然后，接收到的图像将显示在我的应用程序内的ImageView上。为了完成我的任务，我想发送一个位图的字节数组。我能够在imageview上获得第一张图片。但是，只要我点击按钮发送另一个图像，应用程序就无法发送位图。它显示了一个异常“java.io.IOException：Service fiscovery failed。”要成功发送任何图像，我需要在接收/远程设备上重启我的应用程序。可以有人请建议mu问题的解决方案。 logcat也包含在下面。
建立连接的代码：
private class StartConnectionThread extends Thread{
private final BluetoothSocket bluetoothSocket;
private final BluetoothDevice bluetoothDevice;
public StartConnectionThread(BluetoothDevice device){
BluetoothSocket tempBluetoothSocket=null;
bluetoothDevice=device;
try
{
System.out.println(uuid);
tempBluetoothSocket=device.createRfcommSocketToServiceRecord(uuid);
}
catch(IOException ioException)
{
}
bluetoothSocket=tempBluetoothSocket;
}
@Override
public void run() {
// TODO Auto-generated method stub
bluetoothAdapter.cancelDiscovery();
try
{
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
bluetoothSocket.connect();
}
catch(IOException ioException)
{
System.out.println("bluetoothSocketInThread failed");
try
{
bluetoothSocket.close();
}
catch(IOException cancelIOException)
{
}
return;
}
manageConnectedSocket(bluetoothSocket);
}
public void cancel()
{
try
{
bluetoothSocket.close();
}
catch(IOException ioException)
{
}
}
}
接受连接的代码：
private class AcceptConnectionThread extends Thread
{
private final BluetoothServerSocket bluetoothServerSocket;
public AcceptConnectionThread() {
// TODO Auto-generated constructor stub
System.out.println("constructor");
BluetoothServerSocket tempBluetoothServerSocket=null;
try
{
tempBluetoothServerSocket=bluetoothAdapter.listenUsingRfcommWithServiceRecord("My Souvenirs", uuid);
}
catch(IOException ioException)
{
}
bluetoothServerSocket=tempBluetoothServerSocket;
}
@Override
public void run() {
// TODO Auto-generated method stub
BluetoothSocket bluetoothSocket=null;
while(true)
{
try
{
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(bluetoothServerSocket);
if(bluetoothServerSocket!=null)
{
bluetoothSocket=bluetoothServerSocket.accept();
}
System.out.println("accept");
}
catch(IOException ioException){
break;
}
if(bluetoothSocket!=null)
{
manageConnectedSocket(bluetoothSocket);
try {
bluetoothServerSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
}
}
public void cancel()
{
try{
bluetoothServerSocket.close();
}
catch(IOException ioException){
}
}
}
管理连接的代码：
private class ManageConnectedDevicesThread extends Thread
{
private final BluetoothSocket connectedBluetoothSocket;
public ManageConnectedDevicesThread(BluetoothSocket socket) {
// TODO Auto-generated constructor stub
connectedBluetoothSocket=socket;
InputStream tempInputStream=null;
OutputStream tempOutputStream=null;
try
{
tempInputStream=socket.getInputStream();
tempOutputStream=socket.getOutputStream();
}
catch(IOException ioException)
{
}
inputStream=tempInputStream;
outputStream=tempOutputStream;
}
@Override
public void run() {
// TODO Auto-generated method stub
byte[] buffer=new byte[1024*8];
int bytes;
while(true)
{
try
{
bytes=inputStream.read(buffer);
handler.obtainMessage(MESSAGE_READ,bytes,-1,buffer).sendToTarget();
System.out.println("handler");
}
catch(IOException ioException)
{
System.out.println("for handler:" +ioException);
break;
}
}
}
public void write(byte[] bytes)
{
try
{
outputStream.write(bytes);
}
catch(IOException ioException){
System.out.println("exception in wrie tatement of managing connections");
}
}
public void close()
{
try {
connectedBluetoothSocket.close();
} catch (IOException e) {
// TODO: handle exception
}
}
}
重置连接的代码：
void resetConnection()
{
if(inputStream!=null)
{
try {
inputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(outputStream!=null)
{
try {
outputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(startConnectionThread!=null)
{
System.out.println("start wala active tha");
startConnectionThread.cancel();
}
if(acceptConnectionThread!=null)
{
System.out.println("accept wala active tha");
acceptConnectionThread.cancel();
}
if(manageConnectedDevicesThread!=null)
{
System.out.println("manage wala active tha");
manageConnectedDevicesThread.close();
}
}
}
处理程序的代码如下所示：
private final Handler handler=new Handler(){
public void handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_READ:
System.out.println("MESSAGE_READ");
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
byte[] b=readMessage.getBytes();
Bitmap bitmap1=BitmapFactory.decodeByteArray(readBuf, 0, readBuf.length);
imageView.setImageBitmap(bitmap1);
break;
}
};
logcat显示以下内容：
01-25 14:49:31.800: D/dalvikvm(9451): Debugger has detached; object registry had 1 entries
01-25 14:49:38.380: V/BluetoothSocket.cpp(9451): initSocketNative
01-25 14:49:38.380: V/BluetoothSocket.cpp(9451): ...fd 40 created (RFCOMM, lm = 26)
01-25 14:49:38.380: V/BluetoothSocket.cpp(9451): initSocketFromFdNative
01-25 14:49:40.420: D/BluetoothUtils(9451): isSocketAllowedBySecurityPolicy start : device null
01-25 14:49:41.680: I/System.out(9451): bluetoothSocketInThread failed
01-25 14:49:41.680: V/BluetoothSocket.cpp(9451): abortNative
01-25 14:49:41.680: V/BluetoothSocket.cpp(9451): ...asocket_abort(40) complete
01-25 14:49:41.680: V/BluetoothSocket.cpp(9451): destroyNative
01-25 14:49:41.680: V/BluetoothSocket.cpp(9451): ...asocket_destroy(40) complete
提前致谢。
答案 0 :(得分：6)
也许你可以尝试添加thread.sleep一秒钟？见this discussion：
“我能够解决问题的唯一方法是添加一个 在关闭连接之前，thread.sleep持续一秒钟。“
还可以看到dan在this thread上连续发表两条评论：
“我能够在将呼叫分离后才能运行 findBT（）; openBT（）;
否则，mmSocket.connect（）;抛出异常，“服务发现 失败”
但如果我将findBT（）放在onCreate（）中，只需使用按钮即可 openBT（）;它工作正常。
或者，如果我制作第二个按钮，每个按钮一个，它可以正常工作。
连连呢？“
第二条评论的摘录：
Set pairedDevices = mBluetoothAdapter.getBondedDevices(); mmDevice = mBluetoothAdapter.getRemoteDevice(“00:06:66:46:5A:91″); if (pairedDevices.contains(mmDevice)) { statusText.setText(“Bluetooth Device Found, address: ” + mmDevice.getAddress() ); Log.d(“ArduinoBT”, “BT is paired”); }我输入了蓝牙设备的地址。原始代码 找到设备并返回正确的地址，但是 mmSocket.connect（）;生成异常“java.io.IOException： 服务发现失败“
建议？