REST is not a specific interface or technology, but a style. The best example is the web browser itself - your browser sends an HTTP request to a web server that responds with a web page.
The transfer of presentation state in this context: the presentation is a web page, the state is the information contained in it. We could change the view by switching to xml service instead of html, but the information would be the same.
In the RESTful service, you use this style to send data back and forth - the state is sent from the server to you, and then you send the new state back.
So, in a sense, Tomcat will already do REST for you if you put your server pages as resources: http://carsales.com/cars/porsche2149 there may be a resource for your car that you could use HTTP POST or PUT to to change its details.
REST keys use URIs to denote resources, as described above, using JSON or XML as the medium of exchange (although AHAH and other formats are used), as well as how to delete collections.
First, find out what your resources will be and organize your URI system (use URL rewriting, etc.). Then determine the view (s) you want to use. Finally, write a backend to deal with messaging state views around and update the database.
Phil h
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