Up, up and away with Java EE 5

J2EE 1.5 is now Java EE 5.

With version 5 of the Java Platform, Enterprise Edition (Java EE, formerly referred to as J2EE), development of Java enterprise applications has never been easier or faster. The aim of the Java EE 5 platform design has been to streamline the features and add convenience, improve performance, reduce development time, and help developers get products to market that much sooner.

Here are a few of the significant changes:

• Most boilerplate requirements have been eliminated, and XML descriptors are now optional. For example, the ejb-jar.xml descriptor is no longer necessary in most cases.
  
• More defaults are available, with a special emphasis on making them meaningful. Developers now have fewer details to remember.
  
• Web service support is simpler, and the number of supported standards has increased.
  
• The EJB software programming model is significantly simpler.
  
• The new Java Persistence API is available to all Java platform applications, including those based on EJB technology.
  
• JavaServer Faces technology has been added to make web application design more convenient.
  

Other relevant highlights include - Enterprise Application Development Made Easy (annotation framework), Streamlined EJB Software Development (Fewer required classes and interfaces, Optional deployment descriptors, Simple lookups, Simplified & lightweight persistence for object-relational mapping, Interceptors etc..), Easier Access to Resources Through Dependency Injection (object's dependencies are supplied automatically by an entity external to that object), Lightweight Java Persistence API Model, Simpler, Broader Web Service Support (JAX-WS 2.0), Convenient Web Application Design With JavaServer Faces Technology (a server-side framework that provides UI components for building web applications), JavaServer Pages Standard Tag Library, JAXB 2.0 etc..

Read more:

http://java.sun.com/developer/technicalArticles/J2EE/intro_ee5/

If you appreciate the quality of O'Reilly books, this is a great site for Enterprise Java: http://onjava.com/

Go ahead, try the 'Project GlassFish', dive in!