ANDROID 29 FILE PICKER INTENT code example

Example: pdf intent does not have permission to launch

File file= new File(url);
file.setReadable(true, false);

Intent intent = new Intent(Intent.ACTION_VIEW);
Uri pdfUri = FileProvider.getUriForFile(getApplicationContext(), BuildConfig.APPLICATION_ID + ".provider", file);
intent.setDataAndType(pdfUri, "application/pdf");
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

List<ResolveInfo> resInfoList = getApplicationContext().getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
    for (ResolveInfo resolveInfo : resInfoList) {
        String packageName = resolveInfo.activityInfo.packageName;
        getApplicationContext().grantUriPermission(packageName, pdfUri,
                Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
    }

Intent in = Intent.createChooser(intent, "Open File");
startActivity(in);