mBluetoothSocket.connect() prints a line : <p>I have been trying to find a solution for this, but not able to. So I am developing an POS app in Android and I need to print receipts for sales/purchase using a bluetooth printer.</p>

<p>The printing, is working fine, per se, but whenever I call <strong>mBluetoothSocket.connect()</strong>, it prints out <strong>CONNECT "8869-XX-XXXXXX"</strong> on top of the print, which I don't want. I do not want to leave the connection open for long and I want the app to connect only when needed. How to achieve this? Any help guys. Find the code below.0
Thanks in advance.</p>

<pre><code>package anil.com.andoirdbluetoothprint;


import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.Set;
import java.util.UUID;

import android.app.Activity;
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.Toast;


public class MainActivity extends Activity implements Runnable {
    protected static final String TAG = "TAG";
    private static final int REQUEST_CONNECT_DEVICE = 1;
    private static final int REQUEST_ENABLE_BT = 2;
    Button mScan, mPrint, mDisc;
    BluetoothAdapter mBluetoothAdapter;
    private UUID applicationUUID = UUID
            .fromString("00001101-0000-1000-8000-00805F9B34FB");
    private ProgressDialog mBluetoothConnectProgressDialog;
    private BluetoothSocket mBluetoothSocket;
    BluetoothDevice mBluetoothDevice;

    @Override
    public void onCreate(Bundle mSavedInstanceState) {
        super.onCreate(mSavedInstanceState);
        setContentView(R.layout.activity_main);
        mScan = (Button) findViewById(R.id.Scan);
        mScan.setOnClickListener(new View.OnClickListener() {
            public void onClick(View mView) {
                mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
                if (mBluetoothAdapter == null) {
                    Toast.makeText(MainActivity.this, "Message1", Toast.LENGTH_SHORT).show();
                } else {
                    if (!mBluetoothAdapter.isEnabled()) {
                        Intent enableBtIntent = new Intent(
                                BluetoothAdapter.ACTION_REQUEST_ENABLE);
                        startActivityForResult(enableBtIntent,
                                REQUEST_ENABLE_BT);
                    } else {
                        ListPairedDevices();
                        Intent connectIntent = new Intent(MainActivity.this,
                                DeviceListActivity.class);
                        startActivityForResult(connectIntent,
                                REQUEST_CONNECT_DEVICE);
                    }
                }
            }
        });

        mPrint = (Button) findViewById(R.id.mPrint);
        mPrint.setOnClickListener(new View.OnClickListener() {
            public void onClick(View mView) {
                Thread t = new Thread() {
                    public void run() {
                        try {
                            OutputStream os = mBluetoothSocket
                                    .getOutputStream();
                            String BILL = "";
// Before this line, it is printing "CONNECT 88C9-XX-XXXXXX"
                            BILL = "Company Name    \n";
                            BILL = BILL + "Address    \n";
                            BILL = BILL + "---------------    \n";
                            BILL = BILL + "Item1 : Quantity    \n";
                            BILL = BILL + "Rate : 100 $    \n";
                            BILL = BILL + "-----------------\n";
                            BILL = BILL + "Thank You    \n";
                            os.write(BILL.getBytes());
                            //This is printer specific code you can comment ==== &gt; Start

                            // Setting height
                            int gs = 29;
                            os.write(intToByteArray(gs));
                            int h = 104;
                            os.write(intToByteArray(h));
                            int n = 162;
                            os.write(intToByteArray(n));

                            // Setting Width
                            int gs_width = 29;
                            os.write(intToByteArray(gs_width));
                            int w = 119;
                            os.write(intToByteArray(w));
                            int n_width = 2;
                            os.write(intToByteArray(n_width));


                        } catch (Exception e) {
                            Log.e("MainActivity", "Exe ", e);
                        }
                    }
                };
                t.start();
            }
        });

        mDisc = (Button) findViewById(R.id.dis);
        mDisc.setOnClickListener(new View.OnClickListener() {
            public void onClick(View mView) {
                if (mBluetoothAdapter != null)
                    mBluetoothAdapter.disable();
            }
        });

    }// onCreate

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        try {
            if (mBluetoothSocket != null)
                mBluetoothSocket.close();
        } catch (Exception e) {
            Log.e("Tag", "Exe ", e);
        }
    }

    @Override
    public void onBackPressed() {
        try {
            if (mBluetoothSocket != null)
                mBluetoothSocket.close();
        } catch (Exception e) {
            Log.e("Tag", "Exe ", e);
        }
        setResult(RESULT_CANCELED);
        finish();
    }

    public void onActivityResult(int mRequestCode, int mResultCode,
                                 Intent mDataIntent) {
        super.onActivityResult(mRequestCode, mResultCode, mDataIntent);

        switch (mRequestCode) {
            case REQUEST_CONNECT_DEVICE:
                if (mResultCode == Activity.RESULT_OK) {
                    Bundle mExtra = mDataIntent.getExtras();
                    String mDeviceAddress = mExtra.getString("DeviceAddress");
                    Log.v(TAG, "Coming incoming address " + mDeviceAddress);
                    mBluetoothDevice = mBluetoothAdapter
                            .getRemoteDevice(mDeviceAddress);
                    mBluetoothConnectProgressDialog = ProgressDialog.show(this,
                            "Connecting...", mBluetoothDevice.getName() + " : "
                                    + mBluetoothDevice.getAddress(), true, false);
                    Thread mBlutoothConnectThread = new Thread(this);
                    mBlutoothConnectThread.start();
                    // pairToDevice(mBluetoothDevice); This method is replaced by
                    // progress dialog with thread
                }
                break;

            case REQUEST_ENABLE_BT:
                if (mResultCode == Activity.RESULT_OK) {
                    ListPairedDevices();
                    Intent connectIntent = new Intent(MainActivity.this,
                            DeviceListActivity.class);
                    startActivityForResult(connectIntent, REQUEST_CONNECT_DEVICE);
                } else {
                    Toast.makeText(MainActivity.this, "Message", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }

    private void ListPairedDevices() {
        Set&lt;BluetoothDevice&gt; mPairedDevices = mBluetoothAdapter
                .getBondedDevices();
        if (mPairedDevices.size() &gt; 0) {
            for (BluetoothDevice mDevice : mPairedDevices) {
                Log.v(TAG, "PairedDevices: " + mDevice.getName() + "  "
                        + mDevice.getAddress());
            }
        }
    }

    public void run() {
        try {
            mBluetoothSocket = mBluetoothDevice
                    .createRfcommSocketToServiceRecord(applicationUUID);
            mBluetoothAdapter.cancelDiscovery();
            mBluetoothSocket.connect();
            mHandler.sendEmptyMessage(0);
        } catch (IOException eConnectException) {
            Log.d(TAG, "CouldNotConnectToSocket", eConnectException);
            closeSocket(mBluetoothSocket);
            return;
        }
    }

    private void closeSocket(BluetoothSocket nOpenSocket) {
        try {
            nOpenSocket.close();
            Log.d(TAG, "SocketClosed");
        } catch (IOException ex) {
            Log.d(TAG, "CouldNotCloseSocket");
        }
    }

    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            mBluetoothConnectProgressDialog.dismiss();
            Toast.makeText(MainActivity.this, "DeviceConnected", Toast.LENGTH_SHORT).show();
        }
    };

    public static byte intToByteArray(int value) {
        byte[] b = ByteBuffer.allocate(4).putInt(value).array();

        for (int k = 0; k &lt; b.length; k++) {
            System.out.println("Selva  [" + k + "] = " + "0x"
                    + UnicodeFormatter.byteToHex(b[k]));
        }

        return b[3];
    }

    public byte[] sel(int val) {
        ByteBuffer buffer = ByteBuffer.allocate(2);
        buffer.putInt(val);
        buffer.flip();
        return buffer.array();
    }

}
</code></pre>
