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in Technique[技术] by (71.8m points)

android - java.io.FileNotFoundException: /storage/emulated/0/downloadedfilem.jpg (Permission denied)

i am trying to download and store image using Async task in android , when clicking download button getting following error.

    W/System.err: java.io.FileNotFoundException: /storage/emulated/0/downloadedfilem.jpg (Permission denied)
12-07 11:01:00.120 28478-28540/myoracle.com.quotes W/System.err:     at java.io.FileOutputStream.open(Native Method)
12-07 11:01:00.120 28478-28540/myoracle.com.quotes W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
12-07 11:01:00.120 28478-28540/myoracle.com.quotes W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:108)
12-07 11:01:00.120 28478-28540/myoracle.com.quotes W/System.err:     at myoracle.com.quotes.WallpaperDeatilsActivity$ImageDownload.doInBackground(WallpaperDeatilsActivity.java:113)
12-07 11:01:00.120 28478-28540/myoracle.com.quotes W/System.err:     at myoracle.com.quotes.WallpaperDeatilsActivity$ImageDownload.doInBackground(WallpaperDeatilsActivity.java:91)

WallpaperActivity.java

class ImageDownload extends AsyncTask<String, String, String> {

    @Override
    protected String doInBackground(String... params) {
        int count;
        try {

            String root = Environment.getExternalStorageDirectory().toString();

            System.out.println("Downloading");
            URL url = new URL(params[0]);

            URLConnection conection = url.openConnection();
            conection.connect();
            // getting file length
            int lenghtOfFile = conection.getContentLength();

            // input stream to read file - with 8k buffer
            InputStream input = new BufferedInputStream(url.openStream(), 8192);

            // Output stream to write file
            System.out.println(root);
            OutputStream output = new FileOutputStream(root+"/downloadedfilem.jpg");
            byte data[] = new byte[1024];
            long total = 0;
            while ((count = input.read(data)) != -1) {
                total += count;
                // writing data to file
                output.write(data, 0, count);
                System.out.println(count);
            }
            // flushing output
            output.flush();
            // closing streams
            output.close();
           input.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
  1. Android Target Api 7.1.1

Permissions added in manifest

  1. android.permission.READ_EXTERNAL_STORAGE

  2. android.permission.WRITE_EXTERNAL_STORAGE

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1 Reply

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by (71.8m points)

You need to add runtime permission for OS Marshmallow or above. Add this code for permission to allow run time operation in splash activity in onCreate or before download process of image.

if (!checkPermission()) {
    openActivity();
} else {
    if (checkPermission()) {
        requestPermissionAndContinue();
    } else {
        openActivity();
    }
}

Add this method outside onCreate

private static final int PERMISSION_REQUEST_CODE = 200;
private boolean checkPermission() {

        return ContextCompat.checkSelfPermission(this, WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
                ;
    }

private void requestPermissionAndContinue() {
    if (ContextCompat.checkSelfPermission(this, WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
            && ContextCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

        if (ActivityCompat.shouldShowRequestPermissionRationale(this, WRITE_EXTERNAL_STORAGE)
                && ActivityCompat.shouldShowRequestPermissionRationale(this, READ_EXTERNAL_STORAGE)) {
            AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
            alertBuilder.setCancelable(true);
            alertBuilder.setTitle(getString(R.string.permission_necessary));
            alertBuilder.setMessage(R.string.storage_permission_is_encessary_to_wrote_event);
            alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                public void onClick(DialogInterface dialog, int which) {
                    ActivityCompat.requestPermissions(SplashActivity.this, new String[]{WRITE_EXTERNAL_STORAGE
                            , READ_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE);
                }
            });
            AlertDialog alert = alertBuilder.create();
            alert.show();
            Log.e("", "permission denied, show dialog");
        } else {
            ActivityCompat.requestPermissions(SplashActivity.this, new String[]{WRITE_EXTERNAL_STORAGE,
                    READ_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE);
        }
    } else {
        openActivity();
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

    if (requestCode == PERMISSION_REQUEST_CODE) {
        if (permissions.length > 0 && grantResults.length > 0) {

            boolean flag = true;
            for (int i = 0; i < grantResults.length; i++) {
                if (grantResults[i] != PackageManager.PERMISSION_GRANTED) {
                    flag = false;
                }
            }
            if (flag) {
                openActivity();
            } else {
                finish();
            }

        } else {
            finish();
        }
    } else {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}

private void openActivity() {
  //add your further process after giving permission or to download images from remote server.
}

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