Develop Reference

Android USB Otg printer

I am trying to print to usb printer zebra using the following code
As per documentation UsbDeviceConnection#bulkTransfer is value the length which is given in documentation ...#return length of data transferred (or zero) for success,or negative value for failure
My Code is below
package in.silentsudo.andoidprinter.usbprinter;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Map;
import in.silentsudo.andoidprinter.R;
public class MainActivity extends Activity {
private UsbManager mUsbManager;
private UsbDevice mUsbDevice;
private PendingIntent mPermissionIntent;
private UsbDeviceConnection usbConnection;
UsbEndpoint usbWriterEndpoint;
UsbInterface usbInterface;
private static final String ACTION_USB_PERMISSION = "in.silentsudo.usbprinter.USB_PERMISSION";
private StringBuffer logBuffer = new StringBuffer();
private TextView textView;
private Button button;
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
textView = findViewById(R.id.txt_status);
button = findViewById(R.id.btn_print);
addLog("Creating usbConnection");
mUsbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
String usbManagerString = mUsbManager == null ? "USBManager is null" : "USB manager is valid";
addLog(usbManagerString);
}
#Override
protected void onResume() {
super.onResume();
mPermissionIntent = PendingIntent.getBroadcast(this,
0,
new Intent(ACTION_USB_PERMISSION),
0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);
addLog("Registered received with filter :" + ACTION_USB_PERMISSION);
if (mUsbManager != null) {
if (mUsbManager.getDeviceList() != null && mUsbManager.getDeviceList().size() > 0) {
addLog("Total usb devices: " + mUsbManager.getDeviceList().size());
for (Map.Entry<String, UsbDevice> entry : mUsbManager.getDeviceList().entrySet()) {
addLog("\t" + entry.getKey() + " -> " + entry.getValue().getSerialNumber());
mUsbDevice = entry.getValue();
}
} else {
addLog("No device connected");
}
}
addLog("Waiting for usbConnection");
addLog("Setting up interfaces");
setUpInterfaces();
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(mUsbReceiver);
if (usbConnection != null) {
usbConnection.releaseInterface(usbInterface);
}
}
public void setUpInterfaces() {
if (mUsbDevice != null) {
int interfaceCount = mUsbDevice.getInterfaceCount();
addLog("\b" + mUsbDevice.getSerialNumber() + " has total " + interfaceCount + "Interface count");
for (int i = 0; i < interfaceCount; i++) {
final UsbInterface usbInterface = mUsbDevice.getInterface(i);
addLog("\t\tusb at index " + i + " " + getInterfaceDataAsString(usbInterface));
final int endpointCount = usbInterface.getEndpointCount();
addLog("\t\t\t " + usbInterface.getId() + " has total " + endpointCount + " endpoints");
UsbEndpoint point0 = usbInterface.getEndpoint(0);
UsbEndpoint point1 = usbInterface.getEndpoint(1);
printUsbEndPointAsString(point0);
printUsbEndPointAsString(point1);
usbWriterEndpoint = point1;
this.usbInterface = usbInterface;
}
}
}
final String THREAD_TAG = "BG THREAD:-> ";
public boolean connectAndClaim() {
usbConnection = mUsbManager.openDevice(mUsbDevice);
if (usbConnection != null) {
Log.e("Connection:", " connected");
addLog("Device connected");
}
return usbConnection.claimInterface(usbInterface, true);
}
public void writeToPrinter(final String contentToBeWritten) {
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
addLog(THREAD_TAG + "Writing to usbConnection");
addLog(THREAD_TAG + " Content to be written `" + contentToBeWritten + "`");
addLog(THREAD_TAG + " Content size`" + contentToBeWritten.length() + "`");
byte[] bytes = contentToBeWritten.getBytes();
int b = usbConnection.bulkTransfer(usbWriterEndpoint, bytes, bytes.length, 50000);
addLog(THREAD_TAG + "Written status " + b);
addLog(THREAD_TAG + "Written to usbConnection");
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
addLog(THREAD_TAG + exceptionAsString);
}
}
});
thread.start();
}
private void printUsbEndPointAsString(UsbEndpoint point) {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(point.toString());
stringBuilder.append(", type" + point.getType());
stringBuilder.append(", direction" + point.getDirection());
addLog(stringBuilder.toString());
}
private String getInterfaceDataAsString(UsbInterface usbInterface) {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("id = " + usbInterface.getId());
stringBuilder.append(", iClass = " + usbInterface.getInterfaceClass());
stringBuilder.append(", protocol = " + usbInterface.getInterfaceProtocol());
stringBuilder.append(", priSubClassotocol = " + usbInterface.getInterfaceSubclass());
return stringBuilder.toString();
}
public void print(View view) {
String msg = "demo";
if (connectAndClaim()) {
addLog("Claim successful writing to printer");
writeToPrinter(msg);
} else {
addLog("Claim failure");
}
}
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
addLog("ACTION RECEIVED in USB RECEIVER : " + action);
if (ACTION_USB_PERMISSION.equals(action)) {
addLog("action if");
synchronized (this) {
mUsbDevice = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (mUsbDevice != null) {
//call method to set up device communication
addLog("Device received from BROADCAST RECEIVER");
}
} else {
addLog("permission denied for device " + mUsbDevice.getSerialNumber());
}
}
} else {
addLog("action else");
}
}
};
private void addLog(final String msg) {
logBuffer.append(msg);
logBuffer.append("\n");
textView.post(new Runnable() {
#Override
public void run() {
textView.append(msg);
textView.append("\n");
}
});
}
}
I do not see any failure or error logs last message of the thread is also written successfully but contents are not written to printer.
Is there something i am doing wrong please check.

I think your setUpInterfaces() function is incorrect. That's not the way to loop through the endpoints and set the input and output endpoints. It is done like this,
for(i in 0..(usbDevice!!.interfaceCount - 1)){
val usbInterfac = usbDevice!!.getInterface(i)
if(usbInterfac.interfaceClass == UsbConstants.USB_CLASS_CDC_DATA) {
var tout: UsbEndpoint? = null
var tin: UsbEndpoint? = null
val endpointCount = usbInterfac.endpointCount
if (endpointCount >= 2) {
for (j in 0..(endpointCount - 1)) {
if (usbInterfac.getEndpoint(j).type == UsbConstants.USB_ENDPOINT_XFER_BULK) {
if (usbInterfac.getEndpoint(j).direction == UsbConstants.USB_DIR_OUT) {
tout = usbInterfac.getEndpoint(j)
} else if (usbInterfac.getEndpoint(j).direction == UsbConstants.USB_DIR_IN) {
tin = usbInterfac.getEndpoint(j)
}
}
}
if (tout != null && tin != null) {
usbInterface = usbInterfac
endpointOut = tout
endpointIn = tin
}
}
}
}
You are setting output endpoint incorrectly and hence, printer doesn't get your data. (Please don't mind, the solution is in Kotlin language)

how to multiple image upload using intent service with update UI from service

I am android developer .I have face issue ANR when multiple image send in background using intent service.I have call service on Resume() method.I have update UI when step by step image upload finish .My all code in service .But i don't understand why my UI hang.I have created ResultReceiver class for Update UI. Please tell me what is wrong i am doing.
public class UploadImageService extends IntentService {
public static final int STATUS_RUNNING = 0;
public static final int STATUS_FINISHED = 1;
public static final int STATUS_ERROR = 2;
private static final String TAG = "UploadImageService";
public static String SHOW_MSG = "showMsg";
public static String SET_IN_ADAPTER = "setData";
public static String UPLOAD_IMAGE = "uploadImage";
public static String RESULT = "result";
private String threadType, toUser, chatThreadId, gcmRegistrationId, openCloseChatWindowType, recipientName, threadTopicName, attachmentID, attachmentType, currentChunks, originalBase64Img, dateTime, classType, loginUserId;
// Declare Web services variable
private MultipartEntity multipartEntityBuilder;
Database database;
Bundle bundle;
ResultReceiver receiver;
public UploadImageService() {
super(UploadImageService.class.getName());
}
#Override
protected void onHandleIntent(Intent intent) {
//initialize database
database = new Database(UploadImageService.this, Database.DATABASE_NAME, null, Database.DATABASE_VERSION);
Log.d(TAG, "Service Started!");
receiver = intent.getParcelableExtra("receiver");
try {
bundle = new Bundle();
/* Update UI: upload Service is Running */
//receiver.send(STATUS_RUNNING, Bundle.EMPTY);
try {
new UploadThumbImageAsync().execute();
} catch (Exception e) {
e.printStackTrace();
bundle.putString(Intent.EXTRA_TEXT, e.toString());
receiver.send(STATUS_ERROR, bundle);
}
/* new Thread(new Runnable(){
public void run() {
// TODO Auto-generated method stub
while(true)
{
try {
new UploadThumbImageAsync().execute();
} catch (Exception e) {
e.printStackTrace();
bundle.putString(Intent.EXTRA_TEXT, e.toString());
receiver.send(STATUS_ERROR, bundle);
}
}
}
}).start();*/
} catch (Exception e) {
e.printStackTrace();
}
Log.e(TAG, "Service Stopping!");
//this.stopSelf();
}
private class UploadThumbImageAsync extends AsyncTask<String, Void, String> {
/*this method is use for initializing dialog(ProgressDialog,CustomDialog) and showing*/
String toUser, comTypeId, threadType, chatThreadId, threadTopicName, chatAttachmentType, chatMessage, thumbBase64AttachmentPath /*original_image*/, loginUserName, recipientName, originalBase64Image, originalFilePath;
#Override
protected void onPreExecute() {
super.onPreExecute();
//showProgressDialog();
}
/*starts the loading of the data in background in doInBackground() method */
#Override
protected String doInBackground(String... params) {
try {
toUser = params[0];
comTypeId = params[1];
threadType = params[2];
chatThreadId = params[3];
threadTopicName = params[4];
chatAttachmentType = params[5];
chatMessage = params[6];
thumbBase64AttachmentPath = params[7];
loginUserName = params[8];
recipientName = params[9];
originalBase64Image = params[10];
originalFilePath = params[11];
String url;
if (!TextUtils.isEmpty(threadType) && threadType.equals(RecentChatList.SIMPLE_TYPE)) {
url = WS.URL.concat(WS.SAVE_CHAT);
} else {
url = WS.URL.concat(WS.GROUP_SAVE_CHAT);
}
Log.e(TAG, "url_" + chatMessage + " = " + url);
String response = HttpClientExecuteMethod.executeMultipartPostMethod(url, multipartEntityBuilder);
//Log.e(TAG, "save_chat_history_response_" + threadType + "_" + chatMessage + " =" + response);
return response;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/*This method is called after the background computation finishes.
The result of background process in passed in this method as parameters
and now you can dismiss progress dialog
and get the result and display on onPostExecute() method
*/
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
// Log.e(TAG, "chatAttachmentType = " + chatAttachmentType);
updateCounter();
if (result != null) {
JSONObject jo = new JSONObject(result);
String success = null;
final int storeLimit = SharedPreference.getLimit(UploadImageService.this);
if (jo.has(WS.SUCCESS)) {
success = jo.getString(WS.SUCCESS);
if (!TextUtils.isEmpty(success) && success.equals("0")) {
return;
}
if (!TextUtils.isEmpty(success) && success.equals("100")) {
callWsSaveChat(chatAttachmentType, chatMessage, thumbBase64AttachmentPath, originalBase64Image, originalFilePath);
updateRecentChatAndThreadList();
return;
}
if (!TextUtils.isEmpty(success) && success.equals("99")) {
updateRecentChatAndThreadList();
return;
}
}
try {
ArrayList<Chat> saveChatArrayList = null;
if (!TextUtils.isEmpty(success) && success.equals("1")) {
saveChatArrayList = new Chat().getChatHistory(UploadImageService.this, result, TAG, "");
// Log.e(TAG, "onPostExecute_saveChatArrayList.size = " + saveChatArrayList);
ArrayList<Chat> chatHistoryWithoutMsgId = database.getWithoutMsgIdChatHistory(chatThreadId, "#");
//Log.e(TAG, "onPostExecute_chatHistoryWithoutMsgId.size = " + chatHistoryWithoutMsgId.size());
if (saveChatArrayList != null && !saveChatArrayList.isEmpty() && saveChatArrayList.size() > 0) {
for (int i = 0; i < saveChatArrayList.size(); i++) {
final Chat apiChat = saveChatArrayList.get(i);
String apiMsg = apiChat.getMessage();
String apiThumb = null;
if (!TextUtils.isEmpty(apiChat.getAttachment_thumb())) {
apiThumb = apiChat.getAttachment_thumb().concat("$");
}
if (chatHistoryWithoutMsgId != null && !chatHistoryWithoutMsgId.isEmpty() && chatHistoryWithoutMsgId.size() > 0) {
for (int j = 0; j < chatHistoryWithoutMsgId.size(); j++) {
Chat dbChat = chatHistoryWithoutMsgId.get(j);
final String db_message = dbChat.getMessage();
final String db_thumb = dbChat.getAttachment_thumb();
if (apiThumb.equals(db_thumb)) {
database.updateChatList(apiChat, result, "#", db_message, db_thumb, loginUserId, toUser, chatThreadId, threadType);
bundle.putString(RESULT, UPLOAD_IMAGE);
receiver.send(STATUS_FINISHED, bundle);
if (!TextUtils.isEmpty(chatAttachmentType) && chatAttachmentType.equals(getResources().getString(R.string.Image))) {
originalBase64Image = getBase64Image(originalFilePath);
}
int subLength = 1024 * 256;
//Log.e(TAG, "upload_subLength = " + subLength);
int index = 0;
int totalChunks = 0;
if (!TextUtils.isEmpty(originalBase64Image)) {
for (int k = 0; index < originalBase64Image.length(); k++) {
index = index + subLength;
totalChunks++;
}
database.insertOriginalUploadImageList(apiChat.getAttachment_id(), totalChunks, 0, originalFilePath, chatThreadId, apiChat.getDt_sender_created(), chatAttachmentType);
// database.deleteAttachmentImageList(originalBase64Image);
database.deleteAttachmentImageList(originalFilePath);
UploadOriginalImageList(apiChat.getAttachment_id());
}
break;
} else {
// Log.e(TAG, "onPostExecute_not_equal_image");
}
}
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
} else {
// Util.showAlertDialog(mContext, mContext.getResources().getString(R.string.No_internet_connection_available));
}
}
} catch (Exception e) {
e.printStackTrace();
Log.e(TAG, "error = " + e.getMessage());
}
}

There are many methods to upload more images to the server.. one could be including two libraries: apache-mime4j-0.6.jar and httpmime-4.0.1.jar.. After that create your java main code:
import java.io.File;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class FileUploadTest extends Activity {
private static final int SELECT_FILE1 = 1;
private static final int SELECT_FILE2 = 2;
String selectedPath1 = "NONE";
String selectedPath2 = "NONE";
TextView tv, res;
ProgressDialog progressDialog;
Button b1,b2,b3;
HttpEntity resEntity;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv = (TextView)findViewById(R.id.tv);
res = (TextView)findViewById(R.id.res);
tv.setText(tv.getText() + selectedPath1 + "," + selectedPath2);
b1 = (Button)findViewById(R.id.Button01);
b2 = (Button)findViewById(R.id.Button02);
b3 = (Button)findViewById(R.id.upload);
b1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
openGallery(SELECT_FILE1);
}
});
b2.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
openGallery(SELECT_FILE2);
}
});
b3.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if(!(selectedPath1.trim().equalsIgnoreCase("NONE")) && !(selectedPath2.trim().equalsIgnoreCase("NONE"))){
progressDialog = ProgressDialog.show(FileUploadTest.this, "", "Uploading files to server.....", false);
Thread thread=new Thread(new Runnable(){
public void run(){
doFileUpload();
runOnUiThread(new Runnable(){
public void run() {
if(progressDialog.isShowing())
progressDialog.dismiss();
}
});
}
});
thread.start();
}else{
Toast.makeText(getApplicationContext(),"Please select two files to upload.", Toast.LENGTH_SHORT).show();
}
}
});
}
public void openGallery(int req_code){
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,"Select file to upload "), req_code);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
if (requestCode == SELECT_FILE1)
{
selectedPath1 = getPath(selectedImageUri);
System.out.println("selectedPath1 : " + selectedPath1);
}
if (requestCode == SELECT_FILE2)
{
selectedPath2 = getPath(selectedImageUri);
System.out.println("selectedPath2 : " + selectedPath2);
}
tv.setText("Selected File paths : " + selectedPath1 + "," + selectedPath2);
}
}
public String getPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
private void doFileUpload(){
File file1 = new File(selectedPath1);
File file2 = new File(selectedPath2);
import java.io.File;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class FileUploadTest extends Activity {
private static final int SELECT_FILE1 = 1;
private static final int SELECT_FILE2 = 2;
String selectedPath1 = "NONE";
String selectedPath2 = "NONE";
TextView tv, res;
ProgressDialog progressDialog;
Button b1,b2,b3;
HttpEntity resEntity;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv = (TextView)findViewById(R.id.tv);
res = (TextView)findViewById(R.id.res);
tv.setText(tv.getText() + selectedPath1 + "," + selectedPath2);
b1 = (Button)findViewById(R.id.Button01);
b2 = (Button)findViewById(R.id.Button02);
b3 = (Button)findViewById(R.id.upload);
b1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
openGallery(SELECT_FILE1);
}
});
b2.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
openGallery(SELECT_FILE2);
}
});
b3.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if(!(selectedPath1.trim().equalsIgnoreCase("NONE")) && !(selectedPath2.trim().equalsIgnoreCase("NONE"))){
progressDialog = ProgressDialog.show(FileUploadTest.this, "", "Uploading files to server.....", false);
Thread thread=new Thread(new Runnable(){
public void run(){
doFileUpload();
runOnUiThread(new Runnable(){
public void run() {
if(progressDialog.isShowing())
progressDialog.dismiss();
}
});
}
});
thread.start();
}else{
Toast.makeText(getApplicationContext(),"Please select two files to upload.", Toast.LENGTH_SHORT).show();
}
}
});
}
public void openGallery(int req_code){
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,"Select file to upload "), req_code);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
if (requestCode == SELECT_FILE1)
{
selectedPath1 = getPath(selectedImageUri);
System.out.println("selectedPath1 : " + selectedPath1);
}
if (requestCode == SELECT_FILE2)
{
selectedPath2 = getPath(selectedImageUri);
System.out.println("selectedPath2 : " + selectedPath2);
}
tv.setText("Selected File paths : " + selectedPath1 + "," + selectedPath2);
}
}
public String getPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
private void doFileUpload(){
File file1 = new File(selectedPath1);
File file2 = new File(selectedPath2);
String urlString = "http://10.0.2.2/upload_test/upload_media_test.php";
try
{
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(urlString);
FileBody bin1 = new FileBody(file1);
FileBody bin2 = new FileBody(file2);
MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("uploadedfile1", bin1);
reqEntity.addPart("uploadedfile2", bin2);
reqEntity.addPart("user", new StringBody("User"));
post.setEntity(reqEntity);
HttpResponse response = client.execute(post);
resEntity = response.getEntity();
final String response_str = EntityUtils.toString(resEntity);
if (resEntity != null) {
Log.i("RESPONSE",response_str);
runOnUiThread(new Runnable(){
public void run() {
try {
res.setTextColor(Color.GREEN);
res.setText("n Response from server : n " + response_str);
Toast.makeText(getApplicationContext(),"Upload Complete. Check the server uploads directory.", Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
catch (Exception ex){
Log.e("Debug", "error: " + ex.getMessage(), ex);
}
}
}
Now your layout:
<?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="Multiple File Upload from CoderzHeaven"
/>
<Button
android:id="#+id/Button01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Get First File">
</Button>
<Button
android:id="#+id/Button02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Get Second File">
</Button>
<Button
android:id="#+id/upload"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start Upload">
</Button>
<TextView
android:id="#+id/tv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Selected File path : "
/>
<TextView
android:id="#+id/res"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text=""
/>
</LinearLayout>
of course, include the internet permission in your manifest:
<uses-permission android:name="android.permission.INTERNET" />
And voilà. Anyway i followed this example in my case: http://www.coderzheaven.com/2011/08/16/how-to-upload-multiple-files-in-one-request-along-with-other-string-parameters-in-android/ try to see there.. There are 4 methods to upload multiple files. See which you like

How to set page attributes for printing a document in android application

I am creating an android application that consists of printing document from android application. Here I connected android device and printer via usb. I want to set the page attributes such as new line after the end of the line and page heading and page borders.Please tell me how to do this.Big thanks in advance
This is what i had done for printing from android to printer via USB :
package com.developer.printer;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Iterator;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbRequest;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class Printer extends Activity {
Button create_file;
PendingIntent mPermissionIntent;
UsbManager usbManager;
UsbDevice device;
EditText print_text;
UsbDevice printer = null;
private static final int PRINTER_VENDOR_ID = 1256;
private String filename = "MySampleFile.txt";
private String filepath = "PanelFilesstorage";
File myInternalFile;
String data= "This is a sample text";
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
try
{
setContentView(R.layout.activity_demo_printer);
ContextWrapper contextWrapper = new ContextWrapper(getApplicationContext());
File directory = contextWrapper.getDir(filepath, Context.MODE_PRIVATE);
myInternalFile = new File(directory , filename);
print_text = (EditText)findViewById(R.id.editText_printer);
usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
if (deviceList.size() <= 0)
{
Toast.makeText(getApplicationContext(), "Info: No device found", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getApplicationContext(), "No of devices"+deviceList.size(), Toast.LENGTH_SHORT).show();
((TextView) findViewById(R.id.textView_devices))
.setText("No of device : " + deviceList.size());
}
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
int count = 0;
mPermissionIntent = PendingIntent.getBroadcast(getBaseContext(), 0,
new Intent(ACTION_USB_PERMISSION), 0);
while (deviceIterator.hasNext()) {
count++;
device = deviceIterator.next();
Log.i("info", "Device No " + count + "........");
Log.i("info", "Vendor id : " + device.getVendorId());
Log.i("info", "Product id : " + device.getProductId());
Log.i("info", "Device name : " + device.getDeviceName());
Log.i("info", "Device class : " + device.getClass().getName());
Log.i("info", "Device protocol: " + device.getDeviceProtocol());
Log.i("info", "Device subclass : " + device.getDeviceSubclass());
if (device.getVendorId() == PRINTER_VENDOR_ID) {
printer = device;
break;
}
}
findViewById(R.id.button_print).setOnClickListener(
new OnClickListener() {
#Override
public void onClick(View v) {
Log.i("Info", "Print command given");
IntentFilter filter = new IntentFilter(
ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);
if (printer != null) {
usbManager.requestPermission(printer,
mPermissionIntent);
} else {
Log.e("Exception", "Printer not found");
}
}
});
} catch (Exception e) {
Log.e("Exception", "Exception in onCreate " + e.getMessage());
e.printStackTrace();
}
findViewById(R.id.button_create_file).setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
try
{
FileOutputStream fos = new FileOutputStream(myInternalFile+"\n");
fos.write(data.toString().getBytes());
fos.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
});
}
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
try {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action))
{
synchronized (this)
{
final UsbDevice printerDevice = (UsbDevice) intent
.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(
UsbManager.EXTRA_PERMISSION_GRANTED, false))
{
if (printerDevice != null) {
Log.i("Info", "Device permission granted");
startPrinting(printerDevice);
}
}
else
{
Log.d("Debug", "permission denied for device "
+ printerDevice);
}
}
}
} catch (Exception e)
{
Log.e("Exception", "Exception in onRecieve " + e.getMessage());
e.printStackTrace();
}
}
};
public void startPrinting(final UsbDevice printerDevice)
{
new Handler().post(new Runnable()
{
UsbDeviceConnection conn;
UsbInterface usbInterface;
#Override
public void run()
{
try
{
Log.i("Info", "Bulk transfer started");
usbInterface = printerDevice.getInterface(0);
UsbEndpoint endPoint = usbInterface.getEndpoint(0);
conn = usbManager.openDevice(printer);
conn.claimInterface(usbInterface, true);
String myStringData = print_text.getText().toString();
byte[] array = myStringData.getBytes();
ByteBuffer output_buffer = ByteBuffer
.allocate(array.length);
UsbRequest request = new UsbRequest();
request.initialize(conn, endPoint);
request.queue(output_buffer, array.length);
if (conn.requestWait() == request)
{
Log.i("Info", output_buffer.getChar(0) + "");
Message m = new Message();
m.obj = output_buffer.array();
// handler.sendMessage(m);
output_buffer.clear();
}
else
{
Log.i("Info", "No request recieved");
}
int transfered = conn.bulkTransfer(endPoint,
myStringData.getBytes(),
myStringData.getBytes().length, 5000);
Log.i("Info", "Amount of data transferred : " +transfered);
} catch (Exception e)
{
Log.e("Exception", "Unable to transfer bulk data");
e.printStackTrace();
} finally
{
try
{
conn.releaseInterface(usbInterface);
Log.i("Info", "Interface released");
conn.close();
Log.i("Info", "Usb connection closed");
unregisterReceiver(mUsbReceiver);
Log.i("Info", "Brodcast reciever unregistered");
}
catch (Exception e)
{
Log.e("Exception",
"Unable to release resources because : "
+ e.getMessage());
e.printStackTrace();
}
}
}
});
}
}

Android connect to bluetooth device with click button on bluetooth device

I have device bluetooth with button, I want connect to this device after click button on this device, it's there any example to do this?

May this help you.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
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;
static OutputStream outStream;
BluetoothAdapter mBluetoothAdapter;
private UUID applicationUUID = UUID
.fromString("00001101-0000-1000-8000-00805F9B34FB");
private ProgressDialog mBluetoothConnectProgressDialog;
static 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", 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(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 {
if (mBluetoothSocket != null) {
//code for send data on printer to print
sendDataToDevice("Hello");
}
// 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
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", 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 sendDataToDevice(String message) {
byte[] msgBuffer = message.getBytes();
Log.d(TAG, "...Send data: " + message + "...");
try {
outStream.write(msgBuffer);
} catch (IOException e) {
String msg = "In onResume() and an exception occurred during write: "
+ e.getMessage();
if (address.equals("00:00:00:00:00:00"))
msg = msg
+ ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address on line 35 in the java code";
msg = msg
+ ".\n\nTry Connecting the device one more time from the options menu.\n\n";
errorExit("Fatal Error", msg);
}
}
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", 5000).show();
}
};
}
and DeviceListActivty.java is like this
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();
}
};
}

How to connect a mobile and a printer via bluetooth in android?

Can anyone tell me how to connect a mobile and a printer via bluetooth to print a text file in android?
That is,if i click the print button from the android application,the printer has to print that corresponding file.As per my knowledge i have searched for it in Google, but i couldn't find any good samples to do it.Has anyone have at-least one sample android program to do this, it will be better to clear my chaos.
Suggestions please.
Thanks for your precious time!..

Bluetooth Printer Android Example
Create a new android project BlueToothPrinterApp in your editor.
Step 1:
Create main activity like below
com.example.BlueToothPrinterApp / BlueToothPrinterApp.java
package com.example.BlueToothPrinterApp;
import android.app.Activity;
import android.os.Bundle;
import java.io.IOException;
import java.io.OutputStream;
import android.bluetooth.BluetoothSocket;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class BlueToothPrinterApp extends Activity {
/** Called when the activity is first created. */
EditText message;
Button printbtn;
byte FONT_TYPE;
private static BluetoothSocket btsocket;
private static OutputStream btoutputstream;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
message = (EditText) findViewById(R.id.message);
printbtn = (Button) findViewById(R.id.printButton);
printbtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
connect();
}
});
}
protected void connect() {
if (btsocket == null) {
Intent BTIntent = new Intent(getApplicationContext(), BTDeviceList.class);
this.startActivityForResult(BTIntent, BTDeviceList.REQUEST_CONNECT_BT);
} else {
OutputStream opstream = null;
try {
opstream = btsocket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
btoutputstream = opstream;
print_bt();
}
}
private void print_bt() {
try {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
btoutputstream = btsocket.getOutputStream();
byte[] printformat = {
0x1B,
0× 21,
FONT_TYPE
};
btoutputstream.write(printformat);
String msg = message.getText().toString();
btoutputstream.write(msg.getBytes());
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onDestroy() {
super.onDestroy();
try {
if (btsocket != null) {
btoutputstream.close();
btsocket.close();
btsocket = null;
}
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
try {
btsocket = BTDeviceList.getSocket();
if (btsocket != null) {
print_bt();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
Step 2:
com.example.BlueToothPrinterApp / BTDeviceList.java
package com.example.BlueToothPrinterApp;
import java.io.IOException;
import java.util.Set;
import java.util.UUID;
import android.app.ListActivity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class BTDeviceList extends ListActivity {
static public final int REQUEST_CONNECT_BT = 0× 2300;
static private final int REQUEST_ENABLE_BT = 0× 1000;
static private BluetoothAdapter mBluetoothAdapter = null;
static private ArrayAdapter < String > mArrayAdapter = null;
static private ArrayAdapter < BluetoothDevice > btDevices = null;
private static final UUID SPP_UUID = UUID
.fromString(“8 ce255c0 - 200 a - 11e0 - ac64 - 0800200 c9a66″);
// UUID.fromString(“00001101-0000-1000-8000-00805F9B34FB”);
static private BluetoothSocket mbtSocket = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle(“Bluetooth Devices”);
try {
if (initDevicesList() != 0) {
this.finish();
return;
}
} catch (Exception ex) {
this.finish();
return;
}
IntentFilter btIntentFilter = new IntentFilter(
BluetoothDevice.ACTION_FOUND);
registerReceiver(mBTReceiver, btIntentFilter);
}
public static BluetoothSocket getSocket() {
return mbtSocket;
}
private void flushData() {
try {
if (mbtSocket != null) {
mbtSocket.close();
mbtSocket = null;
}
if (mBluetoothAdapter != null) {
mBluetoothAdapter.cancelDiscovery();
}
if (btDevices != null) {
btDevices.clear();
btDevices = null;
}
if (mArrayAdapter != null) {
mArrayAdapter.clear();
mArrayAdapter.notifyDataSetChanged();
mArrayAdapter.notifyDataSetInvalidated();
mArrayAdapter = null;
}
finalize();
} catch (Exception ex) {} catch (Throwable e) {}
}
private int initDevicesList() {
flushData();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(getApplicationContext(), “Bluetooth not supported!!”, Toast.LENGTH_LONG).show();
return -1;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
mArrayAdapter = new ArrayAdapter < String > (getApplicationContext(),
android.R.layout.simple_list_item_1);
setListAdapter(mArrayAdapter);
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
try {
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} catch (Exception ex) {
return -2;
}
Toast.makeText(getApplicationContext(), “Getting all available Bluetooth Devices”, Toast.LENGTH_SHORT)
.show();
return 0;
}
#Override
protected void onActivityResult(int reqCode, int resultCode, Intent intent) {
super.onActivityResult(reqCode, resultCode, intent);
switch (reqCode) {
case REQUEST_ENABLE_BT:
if (resultCode == RESULT_OK) {
Set < BluetoothDevice > btDeviceList = mBluetoothAdapter
.getBondedDevices();
try {
if (btDeviceList.size() > 0) {
for (BluetoothDevice device: btDeviceList) {
if (btDeviceList.contains(device) == false) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress());
mArrayAdapter.notifyDataSetInvalidated();
}
}
}
} catch (Exception ex) {}
}
break;
}
mBluetoothAdapter.startDiscovery();
}
private final BroadcastReceiver mBTReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
try {
if (btDevices == null) {
btDevices = new ArrayAdapter < BluetoothDevice > (
getApplicationContext(), android.R.id.text1);
}
if (btDevices.getPosition(device) < 0) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress() + “\n”);
mArrayAdapter.notifyDataSetInvalidated();
}
} catch (Exception ex) {
// ex.fillInStackTrace();
}
}
}
};
#Override
protected void onListItemClick(ListView l, View v, final int position,
long id) {
super.onListItemClick(l, v, position, id);
if (mBluetoothAdapter == null) {
return;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
Toast.makeText(
getApplicationContext(), “Connecting to” + btDevices.getItem(position).getName() + “, ”
+btDevices.getItem(position).getAddress(),
Toast.LENGTH_SHORT).show();
Thread connectThread = new Thread(new Runnable() {
#Override
public void run() {
try {
boolean gotuuid = btDevices.getItem(position)
.fetchUuidsWithSdp();
UUID uuid = btDevices.getItem(position).getUuids()[0]
.getUuid();
mbtSocket = btDevices.getItem(position)
.createRfcommSocketToServiceRecord(uuid);
mbtSocket.connect();
} catch (IOException ex) {
runOnUiThread(socketErrorRunnable);
try {
mbtSocket.close();
} catch (IOException e) {
// e.printStackTrace();
}
mbtSocket = null;
return;
} finally {
runOnUiThread(new Runnable() {
#Override
public void run() {
finish();
}
});
}
}
});
connectThread.start();
}
private Runnable socketErrorRunnable = new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(), “Cannot establish connection”, Toast.LENGTH_SHORT).show();
mBluetoothAdapter.startDiscovery();
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, Menu.FIRST, Menu.NONE, “Refresh Scanning”);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case Menu.FIRST:
initDevicesList();
break;
}
return true;
}
}
Step 3:
Edit your main.xml file and paste below code.
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp">
<TextView
android:id="#+id/msgtextlbl"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Enter Your Message : "/>
<EditText
android:id="#+id/message"
android:layout_width="fill_parent"
android:layout_height="100dp"
android:layout_below="#+id/msgtextlbl"
android:text=""/>
<Button
android:id="#+id/printButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/message"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dip"
android:text="Print"/>
</RelativeLayout>
Step 4:
Now edit your AndroidManifest.xml
Add bluetooth permission and admin permission.
AndroidManifest.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<manifest
xmlns:android=”http://schemas.android.com/apk/res/android
package=”com.example.BlueToothPrinterApp”
android:versionCode=”1″
android:versionName=”1.0″>
<uses-sdk android:minSdkVersion=”14″ />
<uses-permission android:name=”android.permission.BLUETOOTH”></uses-permission>
<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”></uses-permission>
<application
android:label=”#string/app_name”
android:icon=”#drawable/ic_launcher”>
<activity
android:name=”BlueToothPrinterApp”
android:label=”#string/app_name”>
<intent-filter>
<action android:name=”android.intent.action.MAIN” />
<category android:name=”android.intent.category.LAUNCHER” />
</intent-filter>
</activity>
<activity android:name=”BTDeviceList”></activity>
</application>
</manifest>
Compile and run this application. Enter message and press print button.
You will see list of bluetooth devices. Select bluettoth printer.
Check print on your bluetooth printer.
here is the CODE Reference...

You can use this awesome lib, you can connect to any printer and print easily,
https://github.com/mazenrashed/Printooth
you can download it by:
implementation 'com.github.mazenrashed:Printooth:${LAST_VERSION}'
and use it like:
var printables = ArrayList<Printable>()
var printable = Printable.PrintableBuilder()
.setText("Hello World")
printables.add(printable)
BluetoothPrinter.printer().print(printables)