Flash developers creating RIAs need fast and easy communication to Web Services. Hessian fits this requirement perfectly. With Hessian's growing popularity as a Web Service protocol, we wanted to make these services available to developers targeting the Flash platform.
Ong described using the protocol in more detail:
Hessian isn't a protocol that you have to plan your whole application around; you can add it in at any stage and it's just plug and go. Flash developers now have that flexibility.The Caucho Hessian RIA Demo demonstrates integration between a Java and Flex application in detail. The basics of integrating the two are very straightforward. On the Java side, the service class simply extends the HessianServlet from the API, and is mapped in web.xml with standard JEE syntax. Flex connects to the service in the MXML page using the HessianService class:
<hessian:HessianService xmlns:hessian="hessian.mxml.*" id="service" destination="words"/>
Hessian is a well rounded web service alternative that offers support for Java, C#, Ruby, PHP, and Python in addition to the new ActionScript support. It should offer RIA developers using Adobe Flash and Flex another good alternative for integrating with business services.