Loading WebView from a resource file on Android

This pattern worked for me:

final Uri uri = Uri.parse("file:///android_res/raw/maptest");
webView.loadUrl(uri.toString());

where maptest.html is a file in res/raw folder.  Replacing maptest with maptest.html also works.

The following works to load a file from assets directory:

final Uri uri = Uri.parse("file:///android_asset/maptest.html");
webView.loadUrl(uri.toString());

Note the use of .html extension when loading from assets directory.  When the extension is removed from the URI, the file won't load.