如何在android中通过蓝牙传输文件？

Question

这里我已经让蓝牙可以发现并列出了android中的设备配对，但我无法获得如何在2台设备之间共享文件。请有人帮助我，我被困在这里。

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_ENABLE_BT = 3;
    private static final int REQUEST_DISCOVERABLE_BT = 300;
    private static final int REQUEST_CONNECT_DEVICE_SECURE = 1;

    private BluetoothAdapter bluetoothAdapter;
    Switch switchAB;
    Toolbar toolbar;
    ProgressDialog mProgressDlg;
    private ArrayList<BluetoothDevice> mDeviceList = new ArrayList<BluetoothDevice>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        getSupportActionBar().hide();
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        switchAB = (Switch) findViewById(R.id.switchAB);

        switchAB.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {here i have make the bluetooth discoverable and listed the pairing of devices in android but i am unable to get how to share the files between 2 devices.
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    ensureDiscoverable();
                } else {
                    disableBluetooth();
                }
            }
        });

        ensureDiscoverable();
            }
        });

        registerReceiver(mReceiver, filter);
    }

}