A fully working example can be downloaded here (includes dependencies and scripts). It is the same Bi-Directional Communication example from jCryption, but implemented in Java.

Hi! My name is Gabriel Andery and I am a software developer in São Paulo, Brazil.

As the title says, JavaCryption is a jCryption 2.0 implementation for Java. You can find more about jCryption here.

From jCryption Info page:

In short words jCryption is a javascript HTML-Form encryption plugin, which encrypts the POST/GET-Data that will be sent when you submit a form.
And can also be used for encrypted communication with the server.
It uses the Multiple-precision and Barrett modular reduction libraries for the calculations and jQuery for the rest.

The first JavaCryption release can be found on download page.