My app downloads a PDF file from webserver and opens it with Adobe Reader. But when I click back button on Adobe Reader, my app restarts. I don't want my app to restart when closing Adobe Reader. Note: My app has a file browser dialog, I choose a PDF and display it.
How can I prevent restarting the acitivity when turn back from Adobe Reader?
My code ...
private class DownloadFile extends AsyncTask<String, Void, Void>{
@Override
protected Void doInBackground(String... strings) {
String fileUrl = strings[0]; // -> http://maven.apache.org/maven-1.x/dokuman.pdf
String fileName = strings[1]; // -> dokuman.pdf
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
File folder = new File(extStorageDirectory, "dokuman");
folder.mkdir();
File pdfFile = new File(folder, fileName);
try{
pdfFile.createNewFile();
}catch (IOException e){
e.printStackTrace();
}
Downloader.downloadFile(fileUrl, pdfFile);
return null;
}
}
...
public class Downloader {
private static final int MEGABYTE = 1024 * 1024;
public static void downloadFile(String fileUrl, File directory){
try {
URL url = new URL(fileUrl);
HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
//urlConnection.setRequestMethod("GET");
//urlConnection.setDoOutput(true);
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
FileOutputStream fileOutputStream = new FileOutputStream(directory);
int totalSize = urlConnection.getContentLength();
byte[] buffer = new byte[MEGABYTE];
int bufferLength = 0;
while((bufferLength = inputStream.read(buffer))>0 ){
fileOutputStream.write(buffer, 0, bufferLength);
}
fileOutputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
...
new DownloadFile().execute(host+"dene.pdf", "dokuman.pdf");
File pdfFile = new File(Environment.getExternalStorageDirectory() + "/dokuman/" + "dokuman.pdf"); // -> filename = dokuman.pdf
Uri path = Uri.fromFile(pdfFile);
Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
pdfIntent.setDataAndType(path, "application/pdf");
pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try{
startActivity(pdfIntent);
}catch(ActivityNotFoundException e){
Toast.makeText(MainActivity.this, "No PDF Viewer App!", Toast.LENGTH_SHORT).show();
...
