Java Web Services: Up and Running, 2nd Edition

Servlet-Based Web Services Under GlassFish

GlassFish distinguishes between servlet-based and EJB-based web services. Servlet-based services include REST-style and SOAP-based services of the sort published earlier with Tomcat, Jetty, or a command-line publisher. EJB-based services also may be REST-style or SOAP-based services implemented as Session EJBs. For example, a JAX-RS service might be implemented as a Session EJB. Yet GlassFish and other JASes make it especially attractive to implement legacy @Stateless EJBs as SOAP-based web services because this requires only an additional annotation, @WebService. For servlet-based services under the JAX-WS umbrella, @WebService and @WebServiceProvider instances, the deployment under GlassFish is simpler than the deployment under Tomcat because GlassFish includes, among its libraries, the full Metro implementation of JAX-WS; hence, the Metro JAR files need not be (indeed, should not be) packaged in the deployed WAR file. GlassFish can handle JAX-WS out of the box.

Among the services in the previous chapters deployed with Tomcat or Jetty, all would count as servlet-based in GlassFish terms. They can be deployed, as is, to GlassFish as servlet-based services. Here is a sample selection of services from Chapters 2 and 5. This review focuses on what needs to be included in a WAR file for GlassFish deployment of servlet-based services.

predictions2

This is the predictions RESTful service implemented as an HttpServlet. Here, for review, are the ...