Android 4.4+ Select Multiple Files with UI File Picker

multifilepicker.java

        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);

        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);


// In code that handles the result returned to process the files:

        ClipData clipData = intent.getClipData();
        if (clipData != null) {
            clipData.getItemCount();
        }

// All data is returned in the ClipData object and item count contains the number of items returned.
// Content is the URI for each file to be resolved.