Java Web Services: Up and Running, 2nd Edition

Toward a Lightweight JAS

As a bundle of so many components, features, containers, and services, a JAS is unavoidably complicated software. At issue among Java programmers is whether the benefits that come with a JAS offset the complexity of using a JAS. This complexity stems, in large part, from the fact that so many APIs come into play. For example, a deployed application that incorporates servlets, JSP scripts, JSF scripts, messaging, and EJBs must deal with at least five distinct APIs. This state of affairs accounts for recent efforts among vendors to provide seamless integration of Java EE components, which presumably would result in a lighter-weight, more programmer-friendly framework for doing enterprise Java. JBoss Seam and TomEE OpenEJB are examples. It should be emphasized, however, that Java EE 5 is significantly easier to use than its predecessor, J2EE 1.4. Java EE is definitely moving down the road that lighter frameworks such as Spring cut out for enterprise Java. As a result, the JASes that deliver Java EE applications are more nimble and manageable.

The GlassFish application server is open source and the reference implementation of a JAS. (To be legalistic, a particular snapshot of GlassFish is the RI.) It is available either separately or integrated with the NetBeans IDE. TomEE likewise represents a deliberately lightweight approach to Java EE. This chapter has examples deployed under both GlassFish and TomEE.