Getting Product information like name, price etc using barcode number
Try adding on your API id to the url. https://developers.google.com/shopping-search/v1/getting_started#getting-started
I tried it and was able to get the information of Michael Kors MK5412 Chronograph Watches based of the url of your code.
https://www.googleapis.com/shopping/search/v1/public/products?country=US&q=691464717759&restrictBy=gtin=691464717759&key={your key here}
As a result, you have to fix your url builder to match ^.
Also make sure you put
<uses-permission android:name="android.permission.INTERNET"/>
in your manifest. Credit to this guy: http://androidforums.com/developer-101/100793-java-net-unknownhostexception.html.
Happy coding :)