J2EE 1.4 is an enhancement version of J2EE 1.3. It is the most complete Web services platform ever.
J2EE 1.4 includes:
Java API for XML-Based RPC (JAX-RPC 1.1)
SOAP with Attachments API for Java (SAAJ),
Web Services for J2EE(JSR 921)
J2EE Management Model(1.0)
J2EE Deployment API(1.1)
Java Management Extensions (JMX),
Java Authorization Contract for Containers(JavaACC)
Java API for XML Registries (JAXR)
Servlet 2.4
JSP 2.0
EJB 2.1
JMS 1.1
J2EE Connector 1.5
The J2EE 1.4 features complete Web services support through the new JAX-RPC 1.1 API, which supports service endpoints based on Servlets and enterprise beans. JAX-RPC 1.1 provides interoperability with Web services based on the WSDL and SOAP protocols.
The J2EE 1.4 platform also supports the Web Services for J2EE specification (JSR 921), which defines deployment requirements for Web services and utilizes the JAX-RPC programming model.
In addition to numerous Web services APIs, J2EE 1.4 platform also features support for the WS-I Basic Profile 1.0. This means that in addition to platform independence and complete Web services support, J2EE 1.4 offers platform Web services interoperability.
The J2EE 1.4 platform also introduces the J2EE Management 1.0 API, which defines the information model for J2EE management, including the standard Management EJB (MEJB). The J2EE Management 1.0 API uses the Java Management Extensions API (JMX).
The J2EE 1.4 platform also introduces the J2EE Deployment 1.1 API, which provides a standard API for deployment of J2EE applications.
The J2EE 1.4 platform includes security enhancements via the introduction of the Java Authorization Contract for Containers (JavaACC). The JavaACC API improves security by standardizing how authentication mechanisms are integrated into J2EE containers.
The J2EE platform now makes it easier to develop web front ends with enhancements to Java Servlet and JavaServer Pages (JSP) technologies. Servlets now support request listeners and enhanced filters. JSP technology has simplified the page and extension development models with the introduction of a simple expression language, tag files, and a simpler tag extension API, among other features. This makes it easier than ever for developers to build JSP-enabled pages, especially those who are familiar with scripting languages.
Other enhancements to the J2EE platform include the J2EE Connector Architecture, which provides incoming resource adapter and Java Message Service (JMS) plug ability. New features in Enterprise JavaBeans (EJB) technology include Web service endpoints, a timer service, and enhancements to EJB QL and message-driven beans.
The J2EE 1.4 platform also includes enhancements to deployment descriptors. They are now defined using XML Schema which can also be used by developers to validate their XML structures.
Note: The above information comes from SUN released notes.
