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None of the methods of AsyncTask called

I have a button in my app, which when clicked on will open a PDF (the "Open with" prompt will show). The PDF file is in my assets folder of the app. I have written the code such that an AsyncTask carries out the operation of copying from the assets folder to external storage and then opening it. On running however, none of the methods of AsyncTask class execute as I can see from Logcat. I have seen other similar questions and tried their different answers:
.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR) instead of .execute()
.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[])null);
adding onPreExecute()
The error I get is NullPointerException in the onPostExecute(File file) method, i.e. file is not found. None of the logged statements in the three methods are in logcat.
I call this execute method below:
public void execute() {
Context context = contextWeakReference.get();
if (context != null) {
new CopyFileAsyncTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[])null);
}
}
private class CopyFileAsyncTask extends AsyncTask<Void, Void, File> {
final String appDirectoryName = BuildConfig.APPLICATION_ID;
final File fileRoot = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_DOCUMENTS), appDirectoryName);
#Override
protected void onPreExecute() {
super.onPreExecute();
Log.e("AsyncTask", "onPreExecute");
}
#Override
protected File doInBackground(Void... params) {
Context context = contextWeakReference.get();
AssetManager assetManager = context.getAssets();
File file = new File(fileRoot, fileName);
InputStream in = null;
OutputStream out = null;
try {
file.mkdirs();
if (file.exists()) {
file.delete();
}
file.createNewFile();
in = assetManager.open(fileName);
Log.d(TAG, "In");
out = new FileOutputStream(file);
Log.d(TAG, "Out");
Log.d(TAG, "Copy file");
copyFile(in, out);
Log.d(TAG, "Close");
in.close();
out.flush();
out.close();
return file;
} catch (Exception e)
{
Log.e(TAG, e.getMessage());
}
return null;
}
private void copyFile(InputStream in, OutputStream out) throws IOException
{
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1)
{
out.write(buffer, 0, read);
}
}
#Override
protected void onPostExecute(File file) {
super.onPostExecute(file);
Context context = contextWeakReference.get();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(
Uri.fromFile(file),
"application/pdf");
context.startActivity(intent);
}
}

You Always return null in doInBackground
so
protected void onPostExecute(File file) {
super.onPostExecute(file);
Context context = contextWeakReference.get();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(
Uri.fromFile(file),
"application/pdf");
context.startActivity(intent);
}
File is Always Null
try to edit this
#Override
protected File doInBackground(Void... params) {
Context context = contextWeakReference.get();
AssetManager assetManager = context.getAssets();
File file = new File(fileRoot, fileName);
InputStream in = null;
OutputStream out = null;
try {
file.mkdirs();
if (file.exists()) {
file.delete();
}
file.createNewFile();
in = assetManager.open(fileName);
Log.d(TAG, "In");
out = new FileOutputStream(file);
Log.d(TAG, "Out");
Log.d(TAG, "Copy file");
copyFile(in, out);
Log.d(TAG, "Close");
in.close();
out.flush();
out.close();
} catch (Exception e)
{
Log.e(TAG, e.getMessage());
}
return file;
}

Problem solved!! Apparently Marshmallow does some secret behind the scenes work like not asking for permissions (while installing using android studio). I found that the answer here android mkdirs not working worked for me. You have to go to Settings > Apps > Your app > Turn on Storage permissions. It took me three days to solve this!

OCR text recognition wrong text displaying

I am new to tess-two library. I am able to add that library and getting image from drawable and its even converting, but I am getting wrong text as below:
Here is my complete code:
Bitmap image;
private TessBaseAPI mTess;
String datapath = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//init image
image = BitmapFactory.decodeResource(getResources(), R.drawable.test_image);
//initialize Tesseract API
String language = "eng";
datapath = getFilesDir()+ "/tesseract/";
mTess = new TessBaseAPI();
checkFile(new File(datapath + "tessdata/"));
mTess.init(datapath, language);
}
private void checkFile(File file) {
if (!file.exists()&& file.mkdirs()){
copyFiles();
}
if(file.exists()) {
String datafilepath = datapath+ "/tessdata/eng.traineddata";
File datafile = new File(datafilepath);
if (!datafile.exists()) {
copyFiles();
}
}
}
public void processImage(View view){
String OCRresult = null;
mTess.setImage(image);
OCRresult = mTess.getUTF8Text();
TextView OCRTextView = (TextView) findViewById(R.id.OCRTextView);
OCRTextView.setText(OCRresult);
}
private void copyFiles() {
try {
String filepath = datapath + "/tessdata/eng.traineddata";
AssetManager assetManager = getAssets();
InputStream instream = assetManager.open("tessdata/eng.traineddata");
OutputStream outstream = new FileOutputStream(filepath);
byte[] buffer = new byte[1024];
int read;
while ((read = instream.read(buffer)) != -1) {
outstream.write(buffer, 0, read);
}
outstream.flush();
outstream.close();
instream.close();
File file = new File(filepath);
if (!file.exists()) {
throw new FileNotFoundException();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
I am getting text like:
mmmm.and,mmm,1111 etc
Any help is appreciated.

I had the same issue. It have fixed it 2 minutes ago, you have to resize your image to a bigger size. I used thumbnailator library to do the job:
BufferedImage bigger = Thumbnails.of(oldImage).size(700, 500).asBufferedImage();
I hope it helps and apologise for my awful English.
Note: more information about resizing here

Possible Isuues that may have:
Incorrect OCR-ed text
Add the keywords in your training data
Follow the tutorial Tesseract Tutorial Page

Getting bitmap as null

I am trying to download the image from url and save it in a file. But it's not getting saved. So as I debug the code I found that bitmap is always null.
code:
public class ImageUserTask extends AsyncTask<Void, Void,String> {
String strURL, imageprofile;
Bitmap mBitmap = null;
Context mContext;
private File profileFile;
public ImageUserTask(Context context, String url) {
this.strURL = url;
this.imageprofile = imageprofile;
this.mContext = context;
}
#Override
protected String doInBackground(Void... params) {
Bitmap bitmap = null;
File directory = null;
try {
URL url = new URL(strURL);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
// InputStream input = connection.getInputStream();
bitmap = BitmapFactory.decodeStream(url.openConnection().getInputStream()); //This bitmap is null always
directory = Environment.getExternalStorageDirectory();
// Create a new folder in SD Card
File dir = new File(Environment.getExternalStorageDirectory().getPath() + "/Profile");
if (!directory.exists() && !directory.isDirectory()) {
directory.mkdirs();
}
File mypath = new File(dir,"ProfileImage");
saveFile(mypath, bitmap);
} catch (MalformedURLException e) {
} catch (IOException e) {
}
return directory.getAbsolutePath();
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (result != null) {
imageprofile = result;
}
}
private void saveFile(File fileName, Bitmap bmp) {
FileOutputStream outputStream = null;
try {
outputStream = new FileOutputStream(fileName);
bmp.compress(Bitmap.CompressFormat.JPEG, 100, outputStream); // 100 will be ignored
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
EDIT:
public class ImageUserTask extends AsyncTask<Void,Void,Bitmap> {
String strURL, imageprofile;
Bitmap mBitmap = null;
Context mContext;
private File profileFile;
public ImageUserTask(Context context, String url) {
this.strURL = url;
this.imageprofile = imageprofile;
this.mContext = context;
}
#Override
protected Bitmap doInBackground(Void... params) {
getImageFromUrl(strURL);
return mBitmap;
}
#Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
if (result != null) {
Bitmap bitmap = result;
}
}
public Bitmap getImageFromUrl(String urlString) {
try {
URL url = new URL(urlString);
try {
if(mBitmap!=null) {
mBitmap.recycle();
mBitmap=null;
}
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setDoInput(true);
//Connected to server
connection.connect();
//downloading image
InputStream input = connection.getInputStream();
mBitmap = BitmapFactory.decodeStream(input);
convertBitmapToFile(mBitmap, urlString);
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return mBitmap;
}
public File convertBitmapToFile(Bitmap bitmap, String fileName) {
ContextWrapper cw = new ContextWrapper(mContext);
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File mypath = new File(directory, fileName);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
return mypath;
}
}
What can be the reason? I have added Internet permissions too. Please help. Thank you..

class DownloadFile extends AsyncTask<String, Integer, String> {
String strFolderName;
String shareType;
String downloadPath = "";
Activity mContext;
public DownloadFile(Activity mContext) {
this.mContext = mContext;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String... aurl) {
int count;
try {
String fileName = "your filename with ext";
Log.d("TAG", fileName);
URL url = new URL("your url");
URLConnection conexion = url.openConnection();
conexion.connect();
String PATH = "your Path you want to store" + "/";
downloadPath = PATH + fileName;
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(downloadPath);
byte data[] = new byte[1024];
while ((count = input.read(data)) != -1) {
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String path) {
super.onPostExecute(path);
}
}
This code is work for me

Use the below methods
public Bitmap getImageFromUrl(String urlString) {
Bitmap bmp = null;
try {
URL url = new URL(urlString);
try {
if(bmp!=null) {
bmp.recycle();
bmp=null;
}
bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
convertBitmapToFile(bmp, urlString);
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return bmp;
}
public File convertBitmapToFile(Bitmap bitmap, String fileName) {
ContextWrapper cw = new ContextWrapper(activityRef.getApplicationContext());
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File mypath = new File(directory, fileName);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
return mypath;
}
Add android Permissions for internet and Storage

Please try this
public static Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

Copy file from assets to folder on the sdcard fails

I am using tesseract OCR in my app (Spl!t). When I launch the app from Eclipse to my phone, eng.traineddata is copied into /storage/emulated/0/Pictures/Receipts/tessdata/. But when I installed the app from the market, the eng.traineddata file is not copied into the folder. Is there something wrong with my code?
private File getOutputPhotoFile() {
directory = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"Receipts");
dataPath = directory.getAbsolutePath();
if (!directory.exists()) {
directory.mkdirs();
Toast.makeText(Trans_List.this, "Receipts Folder Created", Toast.LENGTH_SHORT).show();
File tessDir = new File(directory, "tessdata");
if (!tessDir.exists()) {
tessDir.mkdirs();
Toast.makeText(Trans_List.this, "Tessdata Folder Created", Toast.LENGTH_SHORT).show();
File trainingData = new File(tessDir, "eng.traineddata");
if(!trainingData.exists())
new CopyLibrary().execute(LANG);
}
}
String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss")
.format(new Date());
return new File(directory.getPath() + File.separator + "Receipt_"
+ timeStamp + ".jpg");
}
private class CopyLibrary extends AsyncTask<String, Void, Void> {
private void copyFile(InputStream in, OutputStream out)
throws IOException {
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1)
out.write(buffer, 0, read);
}
#Override
protected Void doInBackground(String... s) {
AssetManager assetManager = getAssets();
String[] files = null;
try {
files = assetManager.list("");
} catch (IOException e) {
Log.e("Spl!t", "Failed to get asset file list.");
}
for (String filename : files) {
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
File outFile = new File(dataPath + File.separator
+ "tessdata" + File.separator, LANG
+ ".traineddata");
out = new FileOutputStream(outFile);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
Toast.makeText(Trans_List.this, "Tessdata copied", Toast.LENGTH_SHORT).show();
out = null;
} catch (IOException e) {
Log.e(TAG, "Failed to copy asset file");
}
}
return null;
}
}

Monitoring BufferedInputStream download progress

I'm trying to download a file using an AsyncTask on Android. I want to display a ProgressDialog which should have a progress bar to show the status of the download. I'm using the onProgressUpdate() function for that and implemented a call to publishProgress() in my doInBackground() function. However, the progress dialog only pops up after downloading the file. My code:
protected Long doInBackground(URL...urls) {
for (int i = 0; i < urls.length; i++) {
url = urls[i];
try {
URLConnection conn = url.openConnection();
conn.connect();
totalSize = conn.getContentLength();
BufferedInputStream bis = new BufferedInputStream(url.openStream());
FileOutputStream fos = new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "/forvo_temp.mp3");
BufferedOutputStream bos = new BufferedOutputStream(fos,1024);
byte [] data = new byte[1024];
int x=0; int c=0;
while((x=bis.read(data,0,1024))>=0){
bos.write(data,0,x);
c += 1024;
publishProgress(c);
}
} catch (Exception e) {
e.printStackTrace();
}
}
return 0L; // Don't know what to do with this
}
protected void onProgressUpdate(Integer...args) {
pd = ProgressDialog.show(context, "Downloading...", "Downloading...", true, false);
pd.setProgress(args[0] / totalSize);
}
I guess the whole file is downloaded when I call new BufferedInputStream(url.openStream()). How can I monitor the download progress?

Wrap URL input stream with you own InputStream that just reads bytes and "monitors" the status, e.g. sends notifications.
It is simple: InputStream is an abstract class with only one abstract method:
public abstract int read() throws IOException;
In your case it should read bytes from stream that it wraps.
public class NotifcationInputStream extends InputStream {
private InputStream in;
private int count;
private Collection<ByteListener> listeners = new ArrayList<ByteListener>();
NotificationInputStream(InputStream in) {
this.in = in;
}
public int read() throws IOException {
int b = in.read();
byteReceived(b);
return b;
}
public void addListener(ByteListener listener) {
listeners.add(listener);
}
private void byteReceived(int b) {
for (ByteListener l : listeners) {
l.byteReceived(b, ++count);
}
}
}
public interface ByteListener extends EventListener {
public void byteReceived(int b, int count);
}
The problem here is how to show the process bar: you have to know total number of bytes. You can get it from HTTP header content-length if your resource is static. Otherwise you need appropriate server support or heuristics.

This code is useful showing download items totol size and downloaded size.
private static final int DOWNLOAD_ONPROGRESS = 1;
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DOWNLOAD_ONPROGRESS:
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Downloading latest ...");
progressDialog.setCancelable(true);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
try {
progressDialog.show();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return progressDialog;
default:
return null;
}
}
You can use AsyncTask for downloading the version in background.
private class DownLoad extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
logger.info("LoadDataAsync onPreExecute");
showDialog(DOWNLOAD_ONPROGRESS);
}
#Override
protected String doInBackground(String... aurl) {
int count = 0;
try {
URL url = new URL(aurl[0]);
URLConnection urlConnection = url.openConnection();
urlConnection.connect();
int contentlength = urlConnection.getContentLength();
progressDialog.setMax(contentlength);
String PATH = "";
File file = null;
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)) {
PATH = Environment.getExternalStorageDirectory()
+ "/download/";
file = new File(PATH);
file.mkdirs();
File outputFile = new File(file, "telfaz.apk");
OutputStream fos = new FileOutputStream(outputFile);
InputStream is = new BufferedInputStream(url.openStream());
byte[] buffer = new byte[1024];
long len1 = 0;
while ((count = is.read(buffer)) != -1
&& !downLoad.isCancelled()) {
len1 += count;
publishProgress("" + len1);
fos.write(buffer, 0, count);
}
fos.flush();
fos.close();
is.close();
}
logger.info("Success -> file downloaded succesfully. returning 'success' code");
return Util.APK_DOWNLOAD_SUCCESS;
} catch (IOException e) {
logger.error("Exception in update process : "
+ Util.getStackTrace(e));
}
logger.info("Failed -> file download failed. returning 'error' code");
return Util.APK_DOWNLOAD_FAILED;
}
#Override
protected void onPostExecute(String result) {
logger.info("on DownLoad onPostExecute. result : " + result);
progressDialog.dismiss();
removeDialog(DOWNLOAD_ONPROGRESS);
if (result.equalsIgnoreCase(Util.APK_DOWNLOAD_SUCCESS)) {
Update();
} else {
Toast.makeText(DownloadAllContentsActivity.this,
getString(R.string.updateApplicationFailed),
Toast.LENGTH_LONG).show();
loadDataAsync.execute();
}
}
#Override
protected void onProgressUpdate(String... values) {
if (values != null && values.length > 0) {
progressDialog.setProgress(Integer.parseInt(values[0]));
}
}
}