This is a simple example of how an agnostic front-end that speaks JSON can decouple you from the back-end implementation details. For an example of how this works, pick a language and run the provided command. Then simply navigate to http://localhost:8765 and you should see the page pop up. Go ahead and play with the form and click submit a few times. Then kill the server on the command line with Ctrl+C and start a different one. Don't reload the page - just play around with it some more. The example page should be fully functional as long as it has a server to connect to.
Python 2 and 3
In the root directory, simply run:
$ python python
In the root directory:
$ javac -d java java/com/example/EndpointFun.java && java -cp java com.example.EndpointFun