tickets - Problema de la impresora Bluetooth en android

mini impresora portatil bluetooth

Question

Estoy tratando de imprimir la factura a través de bluetooth utilizando el siguiente código, cuando ejecuto la aplicación, la primera vez que se imprime, pero cuando intento volver a imprimirla, no la imprimo.

package com.sel.bluetooth;
import java.io.OutputStream;
import java.lang.reflect.Method;
import android.app.Activity;
import android.app.Dialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
public class BluetoothPrint extends Activity {
BluetoothAdapter mBTAdapter;
BluetoothSocket mBTSocket = null;
Dialog dialogProgress;
String BILL, TRANS_ID;
String PRINTER_MAC_ID;
final String ERROR_MESSAGE = "There has been an error in printing the bill.";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
// BILL = getIntent().getStringExtra("TO_PRINT");
// TRANS_ID = getIntent().getStringExtra("TRANS_ID");
// PRINTER_MAC_ID = getIntent().getStringExtra("MAC_ID");
PRINTER_MAC_ID = "00:1F:B7:02:8F:44";
//PRINTER_MAC_ID = "00:12:F3:0D:A3:E6";
// TRANS_ID="12345678";
BILL = "/nSale Slip No: 12345678" + " " + "04-08-2011/n";
BILL = BILL + "----------------------------------------";
BILL = BILL + "/n/n";
BILL = BILL + "Total Qty:" + " " + "2.0/n";
BILL = BILL + "Total Value:" + " " + "17625.0/n";
BILL = BILL + "-----------------------------------------";
mBTAdapter = BluetoothAdapter.getDefaultAdapter();
dialogProgress = new Dialog(BluetoothPrint.this);
try {
if (mBTAdapter.isDiscovering())
mBTAdapter.cancelDiscovery();
else
mBTAdapter.startDiscovery();
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
}
System.out.println("BT Searching status :"
+ mBTAdapter.isDiscovering());
if (mBTAdapter == null) {
Toast.makeText(this, "Device has no bluetooth capability",
Toast.LENGTH_LONG).show();
finish();
} else {
if (!mBTAdapter.isEnabled()) {
Intent i = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(i, 0);
}
// Register the BroadcastReceiver
IntentFilter filter = new IntentFilter(
BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter); // Don''t forget to
// unregister during
// onDestroy
dialogProgress.setTitle("Finding printer...");
dialogProgress
.setOnDismissListener(new DialogInterface.OnDismissListener() {
public void onDismiss(DialogInterface dialog) {
dialog.dismiss();
setResult(RESULT_CANCELED);
finish();
}
});
dialogProgress.show();
}
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
}
}
public void printBillToDevice(final String address) {
new Thread(new Runnable() {
public void run() {
runOnUiThread(new Runnable() {
public void run() {
dialogProgress.setTitle("Connecting...");
dialogProgress.show();
}
});
mBTAdapter.cancelDiscovery();
try {
System.out
.println("**************************#****connecting");
BluetoothDevice mdevice = mBTAdapter
.getRemoteDevice(address);
Method m = mdevice.getClass().getMethod(
"createRfcommSocket", new Class[] { int.class });
mBTSocket = (BluetoothSocket) m.invoke(mdevice, 1);
mBTSocket.connect();
OutputStream os = mBTSocket.getOutputStream();
os.flush();
os.write(BILL.getBytes());
System.out.println(BILL);
//mBTSocket.close();
setResult(RESULT_OK);
finish();
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
//Toast.makeText(BluetoothPrint.this, ERROR_MESSAGE, Toast.LENGTH_SHORT).show();
e.printStackTrace();
setResult(RESULT_CANCELED);
finish();
}
runOnUiThread(new Runnable() {
public void run() {
try {
dialogProgress.dismiss();
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
}
}
});
}
}).start();
}
@Override
protected void onDestroy() {
Log.i("Dest ", "Checking Ddest");
super.onDestroy();
try {
if(dialogProgress != null)
dialogProgress.dismiss();
if (mBTAdapter != null)
mBTAdapter.cancelDiscovery();
this.unregisterReceiver(mReceiver);
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
}
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
try {
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
System.out.println("***" + device.getName() + " : "
+ device.getAddress());
if (device.getAddress().equalsIgnoreCase(PRINTER_MAC_ID)) {
mBTAdapter.cancelDiscovery();
dialogProgress.dismiss();
Toast.makeText(BluetoothPrint.this,
device.getName() + " Printing data",
Toast.LENGTH_LONG).show();
printBillToDevice(PRINTER_MAC_ID);
Toast.makeText(BluetoothPrint.this,
device.getName() + " found", Toast.LENGTH_LONG)
.show();
}
}
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
//Toast.makeText(BluetoothPrint.this, ERROR_MESSAGE, Toast.LENGTH_SHORT).show();
}
}
};
@Override
public void onBackPressed() {
try {
if (mBTAdapter != null)
mBTAdapter.cancelDiscovery();
this.unregisterReceiver(mReceiver);
} catch (Exception e) {
Log.e("Class ", "My Exe ", e);
}
setResult(RESULT_CANCELED);
finish();
}
}

Answer 1

Acabo de comentar //mBTSocket.close();

Luego, justo antes, agregue:

if (mBTAdapter != null)
mBTAdapter.cancelDiscovery();

y todo va bien!

Answer 2

Aquí está el código de trabajo perfecto para la impresora blue-tooth en Android

device_list.xml

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:id="@+id/title_paired_devices"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:text="My Text" android:visibility="gone"
android:background="#666" android:textColor="#fff"
android:paddingLeft="5dip" />
<ListView android:id="@+id/paired_devices"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:stackFromBottom="true" android:layout_weight="1" />
</LinearLayout>

nombre_de_dispositivo.xml

 <?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:textSize="18sp" android:padding="5dip" /> 

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="@string/hello" />
<Button android:text="Scan" android:id="@+id/Scan"
android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
<Button android:text="Print" android:id="@+id/mPrint"
android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
<Button android:text="Dissable" android:id="@+id/dis"
android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
</LinearLayout>

DeviceListActivity.java

 package com.sel.code;
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class DeviceListActivity extends Activity
{
protected static final String TAG = "TAG";
private BluetoothAdapter mBluetoothAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
@Override
protected void onCreate(Bundle mSavedInstanceState)
{
super.onCreate(mSavedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.device_list);
setResult(Activity.RESULT_CANCELED);
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
ListView mPairedListView = (ListView) findViewById(R.id.paired_devices);
mPairedListView.setAdapter(mPairedDevicesArrayAdapter);
mPairedListView.setOnItemClickListener(mDeviceClickListener);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> mPairedDevices = mBluetoothAdapter.getBondedDevices();
if (mPairedDevices.size() > 0)
{
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice mDevice : mPairedDevices)
{
mPairedDevicesArrayAdapter.add(mDevice.getName() + "/n" + mDevice.getAddress());
}
}
else
{
String mNoDevices = "None Paired";//getResources().getText(R.string.none_paired).toString();
mPairedDevicesArrayAdapter.add(mNoDevices);
}
}
@Override
protected void onDestroy()
{
super.onDestroy();
if (mBluetoothAdapter != null)
{
mBluetoothAdapter.cancelDiscovery();
}
}
private OnItemClickListener mDeviceClickListener = new OnItemClickListener()
{
public void onItemClick(AdapterView<?> mAdapterView, View mView, int mPosition, long mLong)
{
mBluetoothAdapter.cancelDiscovery();
String mDeviceInfo = ((TextView) mView).getText().toString();
String mDeviceAddress = mDeviceInfo.substring(mDeviceInfo.length() - 17);
Log.v(TAG, "Device_Address " + mDeviceAddress);
Bundle mBundle = new Bundle();
mBundle.putString("DeviceAddress", mDeviceAddress);
Intent mBackIntent = new Intent();
mBackIntent.putExtras(mBundle);
setResult(Activity.RESULT_OK, mBackIntent);
finish();
}
};
} 

Main.java

 package com.sel.code;
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 Main 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);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.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(Main.this, "Message1", 2000).show();
} else {
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent,
REQUEST_ENABLE_BT);
} else {
ListPairedDevices();
Intent connectIntent = new Intent(Main.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 = "";
BILL = "/nInvoice No: ABCDEF28060000005" + " "
+ "04-08-2011/n";
BILL = BILL
+ "-----------------------------------------";
BILL = BILL + "/n/n";
BILL = BILL + "Total Qty:" + " " + "2.0/n";
BILL = BILL + "Total Value:" + " "
+ "17625.0/n";
BILL = BILL
+ "-----------------------------------------/n";
os.write(BILL.getBytes());
//This is printer specific code you can comment ==== > 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));
// Print BarCode
int gs1 = 29;
os.write(intToByteArray(gs1));
int k = 107;
os.write(intToByteArray(k));
int m = 73;
os.write(intToByteArray(m));
String barCodeVal = "ASDFC028060000005";// "HELLO12345678912345012";
System.out.println("Barcode Length : "
+ barCodeVal.length());
int n1 = barCodeVal.length();
os.write(intToByteArray(n1));
for (int i = 0; i < barCodeVal.length(); i++) {
os.write((barCodeVal.charAt(i) + "").getBytes());
}
//printer specific code you can comment ==== > End
} catch (Exception e) {
Log.e("Main", "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(Main.this,
DeviceListActivity.class);
startActivityForResult(connectIntent, REQUEST_CONNECT_DEVICE);
} else {
Toast.makeText(Main.this, "Message", 2000).show();
}
break;
}
}
private void ListPairedDevices() {
Set<BluetoothDevice> mPairedDevices = mBluetoothAdapter
.getBondedDevices();
if (mPairedDevices.size() > 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(Main.this, "DeviceConnected", 5000).show();
}
};
public static byte intToByteArray(int value) {
byte[] b = ByteBuffer.allocate(4).putInt(value).array();
for (int k = 0; k < 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();
}
}

UnicodeFormatter.java

 package com.sel.code;
import java.io.*;
public class UnicodeFormatter {
static public String byteToHex(byte b) {
// Returns hex String representation of byte b
char hexDigit[] = { ''0'', ''1'', ''2'', ''3'', ''4'', ''5'', ''6'', ''7'', ''8'', ''9'',
''a'', ''b'', ''c'', ''d'', ''e'', ''f'' };
char[] array = { hexDigit[(b >> 4) & 0x0f], hexDigit[b & 0x0f] };
return new String(array);
}
static public String charToHex(char c) {
// Returns hex String representation of char c
byte hi = (byte) (c >>> 8);
byte lo = (byte) (c & 0xff);
return byteToHex(hi) + byteToHex(lo);
}
} // class