cannot display PDF file from assets folder as MODE_WORLD_READABLE no longer supported

Question

The following code is working absolutely fine in devices with API 22 but in devices with API 24 it gives the following error:

java.lang.SecurityException: MODE_WORLD_READABLE no longer supported

Here is my code:

private void CopyReadAssets(String filename) {
    AssetManager assetManager = getAssets();
    InputStream in = null;
    OutputStream out = null;
    File file = new File(getFilesDir(), filename);

    try {
        in = assetManager.open(filename);
            out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE);

        copyFile(in, out);
        in.close();
        in = null;
        out.flush();
        out.close();
        out = null;

        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(file),"application/pdf");

        startActivity(intent);
    } catch (Exception e)
    {
        Log.e("cra",e.toString());
        Toast.makeText(PdfFilesList.this, "cra: "+e.toString(), Toast.LENGTH_SHORT).show();
    }
}

If I change MODE_WORLD_READABLE to MODE_PRIVATE then it stops working in all devices. devices with API 22 give the following error

11-16 12:00:53.133 16531-31103/? E/DisplayData: openFd: java.io.FileNotFoundException: Permission denied
11-16 12:00:53.134 16531-31103/? E/PdfLoader: Can't load file (doesn't open)  Display Data [PDF : 818 New Jeevan Nidhi.pdf] +FileOpenable, uri: file:///data/data/com.user.plansmart/files/818%20New%20Jeevan%20Nidhi.pdf

Device with API 24 throw the following exception

11-16 12:05:00.100 2682-2682/com.user.plansmart E/cra: android.os.FileUriExposedException: file:///data/user/0/com.user.plansmart/files/827%20Jeevan%20Rakshak.pdf exposed beyond app through Intent.getData()

Can someone help me in resolving the issue.

Thanks.

Answer 1

Found a workaround instead of using MODE_WORLD_READABLE since looking here

int MODE_WORLD_READABLE This constant was deprecated in API level 17. Creating world-readable files is very dangerous, and likely to cause security holes in applications. It is strongly discouraged; instead, applications should use more formal mechanism for interactions such as ContentProvider, BroadcastReceiver, and Service. There are no guarantees that this access mode will remain on a file, such as when it goes through a backup and restore.

private void CopyReadAssets(String filename) {
    AssetManager assetManager = getAssets();
    InputStream in;
    OutputStream out;

    try {
        in = assetManager.open(filename);
        String outDir = Environment.getExternalStorageDirectory().getAbsolutePath();

        File outFile = new File(outDir, filename);
        if(outFile.createNewFile()){
            return;
        }

        out = new FileOutputStream(outFile);

        copyFile(in, out);
        in.close();
        out.flush();
        out.close();

        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(outFile), "application/pdf");

        startActivity(intent);
    } catch (Exception e) {
        Log.e("cra", e.toString());
        Toast.makeText(this, "cra: " + e.toString(), Toast.LENGTH_SHORT).show();
    }
}

For devices, after M you need to ask permission separately.

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission
                        .READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE},
                102);
    }
} else {
    CopyReadAssets("yourpdf.pdf");
}

Then in onRequestPermissionsResult implement, your code.

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    switch (requestCode) {
        case 102:
            CopyReadAssets("yourpdf.pdf");
            break;
    }
}

Hope this helps

Answer 2

You should use a FileProvider to serve your files with Intent.ACTION_VIEW.

Code doing so you can find plenty on this site.