Java Web Services in a Nutshell

An Example JAXM Application

In order to demonstrate the JAXM APIs and show you how to set up the JAXM provider configuration, we’ll look at the implementation of a very simple web service that simply accepts a message and returns it to its sender, having added an XML element containing the date and time at which the message was processed. The process of returning the message requires the receiver to explicitly address the message to its originator and send it back via its own local provider. In other words, each time this service is used, two asynchronous messages are sent, one in each direction.

Since this is a JAXM example, both the sender and the receiver are implemented as servlets in a web container. Both of them need to be able to receive SOAP messages and dispatch them to application code. In Chapter 3, we used a private class called SAAJServlet as the base class for our example web service, but in this chapter, we are going to use the class javax.xml.messaging.JAXMServlet instead. These two servlets are virtually identical — the only real difference between them is that JAXMServlet is included as part of the JAXM API and should therefore be available in all JAXM implementations, whereas SAAJServlet is a private class developed from example code in the JWSDP distribution. We could, of course, have used JAXMServlet in Chapter 3 instead of creating SAAJServlet, but to do so would have introduced a dependency on JAXM, which we wanted to avoid. Like SAAJServlet, JAXMServlet delivers ...