使用安卓设备通过SPP蓝牙发送数据

Question

我正在尝试从Android设备向支持串行端口配置文件（SPP）的远程蓝牙设备发送数据。我注意到每次按下按钮后打开和关闭一个套接字都太慢了。在Run()和Onclick()函数中应该执行哪些套接字命令？以下是执行蓝牙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，出现以下错误信息:

    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。

- user1147515

---

针对您所需的蓝牙I/O排序，什么是最小的测试用例？所有蓝牙操作是否都可以在一个测试函数内完成？如果您能提供这个，那么调试可能会更容易。 - speciousfool

您在清单文件中设置了正确的权限吗？ - ligi

我也遇到了同样的问题。你有找到解决方案吗？ - Zacharias Manuel

Answer 1

如果你确定连接已经建立且没有任何错误，并且你可以获取到 socket，请尝试在 run() 方法中将你的 OutputStream 成员变量指定如下：

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);
    }       
}

你实际上并没有关闭套接字，但这应该可以工作。在 write() 调用之前确保与主设备的连接不会丢失。

- Saro Taşciyan