android - 使用android设备通过SPP通过蓝牙发送数据

Question

我正在尝试将数据从 Android 设备发送到支持串行端口配置文件 (SPP) 的远程蓝牙设备。我注意到每次按下按钮后打开和关闭 socket 时，它都太慢了。 Run() 和 Onclick() 函数中应该执行哪些套接字命令？下面是一个做蓝牙IO的类:

public class Selecteddevice extends Activity implements OnClickListener {

private static final String TAG = "THINBTCLIENT";
private BluetoothAdapter mBluetoothAdapter = null;
private BluetoothDevice device;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;

private static final UUID MY_UUID = 
        UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
public static String address;

@Override
public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.selecteddevice);
    findViewById(R.id.toggleButton1).setOnClickListener(this);
    findViewById(R.id.toggleButton2).setOnClickListener(this);
    findViewById(R.id.toggleButton3).setOnClickListener(this);

}

@Override
public void onStart() {
    super.onStart();

    String address = getIntent().getStringExtra("address");
    TextView tv1 = (TextView) findViewById(R.id.textView_address);
    tv1.setText("                       DEVICE ADDRESS:      " +  address);

    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    device = mBluetoothAdapter.getRemoteDevice(address);
    run();
}

public void run(){
    mBluetoothAdapter.cancelDiscovery();
    try {
        btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);

    } catch (IOException e) 
    {   
        Log.e(TAG, "ON START: Socket creation failed.", e);
    }

    try {
        btSocket.connect();

    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: Socket connection failed.", e);
    }   
}

public void sendTestString(String s){
    try {
        outStream = btSocket.getOutputStream();

    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: OutputStream creation failed.", e);
    }

    try {
        outStream.write(s.getBytes());
        Log.d(TAG, "sendTestByte: OutputStream write succeeded.");

    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: OutputStream writefailed.", e);
    }       
}


public void onClick(View v){
    switch(v.getId())
    {
    case R.id.toggleButton1:
        this.sendTestString("1");
        break;
    case R.id.toggleButton2:
        this.sendTestString("2");
        break;
    case R.id.toggleButton3:
        this.sendTestString("3");
        break;
    }
}           

@Override
public void onPause() {
    super.onPause();
    if (outStream != null) {
        try {
            outStream.flush();
        } catch (IOException e5) 
        { 
            Log.e(TAG, "ON PAUSE: Couldn't flush output stream.", e5);
        }
    }
    try {
        btSocket.close();
    } catch (IOException e6) 
    {
        Log.e(TAG, "ON PAUSE: Unable to close socket.", e6);
    }
}

@Override
public void onStop() {
    super.onStop();

}

@Override
public void onDestroy() {
    super.onDestroy();

}

---

我的程序在配对后崩溃并出现错误信息:

    07-27 13:00:57.483: E/THINBTCLIENT(7855): sendTestByte: OutputStream writefailed.
    07-27 13:00:57.483: E/THINBTCLIENT(7855): java.io.IOException: socket closed
    07-27 13:00:57.483: E/THINBTCLIENT(7855):   at  
    android.bluetooth.BluetoothSocket.write(BluetoothSocket.java:331)
    ...

我做错了什么？

谢谢。

Answer 1

如果您确定连接建立没有任何错误并且您可以获得套接字，请尝试在run() 中分配您的OutputStream 成员> 方法如下:

public void run()
{
    mBluetoothAdapter.cancelDiscovery();
    try 
    {
        btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);           
    } catch (IOException e) 
    {   
        Log.e(TAG, "ON START: Socket creation failed.", e);
    }

    try 
    {
        btSocket.connect();     
    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: Socket connection failed.", e);
    }   

    try 
    {
        outStream = btSocket.getOutputStream();
    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: OutputStream creation failed.", e);
    }
}

public void sendTestString(String s)
{    
    try 
    {
        outStream.write(s.getBytes());
        outSttream.flush(); // <-- Try flush to force sending data in buffer
        Log.d(TAG, "sendTestByte: OutputStream write succeeded.");
    } catch (IOException e) 
    {       
        Log.e(TAG, "sendTestByte: OutputStream writefailed.", e);
    }       
}

您实际上并没有关闭套接字，但这应该有效。在 write() 调用

之前确保与主设备的连接没有丢失