Requests can respond to different request formats, including html, json, xml, and pdf.
By default, all requests can respond to html and pdf formats. You can allow for more formats by using the @formats annotation. Possible values include html, pdf, json, and xml.
By default, all requests are rendered using an html format.
You can render a request in a different format by either specifying a format parameter in the URL (http://myapp.com/product/show/1?format=pdf) or by adding a format extension in the URL (http://myapp.com/product/show/1.pdf).