After a quick look at the Apache Sling documentation it seemed that adding such a feature to Sling/ Day CQ would be pretty easy, especially as goo.gl uses the Google Chart API to create the images.
To deal with requests within Sling based on the url extension, a Servlet Service must be added via an OSGi bundle and use service reference properties to detail which extensions/paths/selectors/methods/prefix are handled by this servlet. Thanks to the maven-bundle-plugin and maven-scr-plugins, packaging this bundle for deployment using Maven is a piece of cake.
The Servlet is quite simple. Here are the SCR annotations from the Servlet class javadoc that tell the Sling what type of requests this Servlet will service:
/** * @scr.service interface="javax.servlet.Servlet" * @scr.property name="sling.servlet.resourceTypes" * value="sling/servlet/default" * * @scr.property name="sling.servlet.extensions" value = "qr" */
and here are the couple of lines that create the redirect URL for the QR Code image and send that in the response.
private static final String baseUrl = "http://chart.apis.google.com/chart?cht=qr&chs=150x150&choe=UTF-8&chld=H&chl=";
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ... {
resp.sendRedirect(baseUrl + removeQRExtension(req));
}
protected String removeQRExtension(HttpServletRequest req) {
StringBuffer url = req.getRequestURL();
return url.substring(0, url.length() -3);
}
Once the OSGi bundle is installed, you can add the .qr extension to any url on your Sling/CQ5 server and get back a QR code for that URL. For example the CQ5 URL
http://localhost:4502/libs/cq/core/content/welcome.html.qr
will give you this QR Code.
Although QR codes not yet made it mainstream, they provide a great way for mobile users to grab information quickly and there seem to be plenty of QR code readers out there. I have been using QuickMark on the iPhone and that works great for me.
The full code can be found here
and the compiled OSGi bundle can be found here
