How to Upload PDFs and Images (pre-2.4.0)

Since version 2.4.0 the File Import (“Open With”) feature should be used.

General considerations

Enabling your app to open PDFs and images allows your users to open any kind of files which are identified by the OS as PDFs or images. Make sure to check the MIME type and that the file size is below an acceptable threshold (5MB for example). It is also advisable to check the first bytes of the incoming files to determine their type and allow only PDFs and known image types.

Registering PDF and image file types

Add the following intent filter to the Activity in your AndroidManifest.xml you wish to receive incoming PDFs and images:

<activity android:name=".ui.MyActivity">
    <intent-filter android:label="@string/app_name">
        <action android:name="android.intent.action.VIEW" />
        <action android:name="android.intent.action.SEND" />
        <category android:name="android.intent.category.DEFAULT" />
        <data android:mimeType="image/*" />
        <data android:mimeType="application/pdf" />


We recommend adding ACTION_VIEW to the intent filter to also allow users to send PDFs and images to your app from apps which don’t implement sharing with ACTION_SEND but enable viewing the PDF or file with other apps.

Reading files from external storage

Since Android 4.4 (API Level 19) the READ_EXTERNAL_STORAGE permission has to be declared to access files outside of the app-specific directories. Declare this permission in your AndroidManifest.xml:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

Since the introduction of Run Time Permissions with Android 6.0 (API Level 23) your app also has to request permission from the user before accessing a PDF or an image file outside of the app-specific directories.

We recommend checking for the permission whenever your app receives a PDF or an image and before accessing it. If an explanation is requested by the system to be shown to the user we highly recommend providing one.

It is required to handle the case where the user did not grant permissions. We recommend showing an explanation and providing a link to your app’s App info page in the Settings app with a short guide on how to grant the permission there.

The Intent for opening the App info page can be created as follows:

Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts(Uri."package", BuildConfig.APPLICATION_ID, null);

Handling incoming PDFs and images

When your app is requested to handle a PDF or an image your Activity (declaring the intent filter we mentioned previously) is launched or resumed with an Intent having ACTION_VIEW or ACTION_SEND.

Checking whether the Intent has the required action:

String action = intent.getAction();
if (Intent.ACTION_VIEW.equals(action) || Intent.ACTION_SEND.equals(action)) {

The Intent will contain an Uri pointing to the PDF or image. The Uri can be in the data field or since Android 4.1 (API Level 16) it can also be in the clipData field.


To also support ACTION_VIEW we recommend using data and clipData. The Androd example uses intent.getParcelableExtra(Intent.EXTRA_STREAM) to extract the Uri, but this works only with ACTION_SEND.

Getting the Uri from the Intent:

Uri uri = intent.getData();
if (uri == null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
    ClipData clipData = intent.getClipData();
    if (clipData != null && clipData.getItemCount() > 0) {
        uri = clipData.getItemAt(0).getUri();

We recommend checking the MIME type of Intent. The MIME type can be in the type field or since Android 4.1 (API Level 16) it can also be in the clipData field.

Getting the MIME type from the Intent:

List<String> mimeTypes = new ArrayList<>();
String type = context.getContentResolver().getType(data);
if (type == null) {
    type = intent.getType();
if (type == null) {
    String extension = MimeTypeMap.getFileExtensionFromUrl(url);
    if (extension != null) {
        final MimeTypeMap mime = MimeTypeMap.getSingleton();
        type = mime.getMimeTypeFromExtension(extension);
if (type != null) {
    ClipData clipData = intent.getClipData();
    if (clipData != null) {
        ClipDescription description = clipData.getDescription();
        for (int i = 0; i < description.getMimeTypeCount(); i++) {
            type = description.getMimeType(i);

Having the Uri, the contents of the PDF or image files can be read using the ContentResolver.

Reading the PDF or image into a byte array:

byte[] bytes = null;
ContentResolver contentResolver = activity.getContentResolver()
InputStream inputStream = null;
try {
    inputStream = contentResolver.openInputStream(uri);
    if (inputStream != null) {
        // ByteStreams is a utility class from Google’s Guava library
        bytes = ByteStreams.toByteArray(inputStream);
} finally {
    if (inputStream != null) {

The byte array from the example above can be directly uploaded to the Gini API for information extraction.

Showing a preview of the PDF’s first page

We recommend showing a preview of the PDF’s first page or of the image while the document is being analyzed. Rendering PDFs is possible since Android 5.0 (API Level 21). On older versions we recommend showing a placeholder image.

The following code shows how to generate a preview of the PDF’s first page on Android 5.0 and newer versions:

Bitmap bitmap = null;
ContentResolver contentResolver = activity.getContentResolver();
ParcelFileDescriptor fileDescriptor = contentResolver.openFileDescriptor(uri, "r");
if (fileDescriptor != null) {
    PdfRenderer pdfRenderer = new PdfRenderer(fileDescriptor);
    if (pdfRenderer != null) {
        if (pdfRenderer.getPageCount() > 0) {
            PdfRenderer.Page page = pdfRenderer.openPage(0);
            // Set the width and height based on the desired preview size
            // and the aspect ratio of the pdf page
            int bitmapWidth = …;
            int bitmapHeight =  …;
            // Create a white bitmap to make sure that PDFs without
            // a background color are rendered on a white background
            int[] colors = createWhiteColorArray(bitmapWidth, bitmapHeight);
            bitmap = Bitmap.createBitmap(colors, bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
            page.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);