Java EE and Grails: Communication with WebServices? Which framework?

Question

Hy, I'm developing a Grails app which has to communicate with an existing Java EE application (built with EJB2). Both the "legacy" app and the new Grails app will offer services and consume them.

For intercompatibility reasons, I'm thinking of communicating using WebServices. Now I'm wondering which frameworks I should use on both sides.

Since the Java EE application now runs under JDK5, I could use JAX-WS on I guess it would make sense to use Metro (https://jax-ws-commons.dev.java.net/grails/) on the Grails side. Does anybody have experiences with that? Or other suggestions?

Answer 1

If both the Grails and EJB applications live on the same LAN then there is nothing wrong with using RMI. Its the default way of talking to EJB's, is native to Java and is supported in Grails.

If you need to use Web Services then your container will have built in support for exposing the EJB's as Web Services (assuming J2EE 1.4 or later). Which container are you using?

If you cant use (or don't trust) the containers WS support then its best to pick a framework that you can use in both applications, thereby avoiding compatibility issues. Metro has worked well for me standalone but I haven't tried it with Grails.

Also there are more lightweight ways of exchanging XML messages than full SOAP'y Web Services. Hessian and Burlap are examples, plus Spring has its own HTTP messaging framework.