This plugin allows you to create QR codes as part of your Grails application without the need for an external service.
grails install-plugin qrcode
Creates QRCode as part of your Grails application. A simple to use TagLib provides intuitive ways to embed QRCodes directly onto any page in your Grails application.For example embedding this simple tag in your main.gsp will create a QRCode show/hide block on every page in your application allowing for easy sharing with an Android or iPhone device that has a QRCode barcode reader installed.
This tag creates a QRCode containing any text you want to embed in a QRCode:
<qrcode:image text="Some arbitrary text."/>