Java framework Spring 3.0 ready to roll
The Spring Framework was founded in 2002 with the aim of simplifying the programming of enterprise Java applications. For many Java developers, the open source Java application framework has more than exceeded this ambition. Now, eight years later, chief architect Jürgen Höller has released version 3.0 for download. It includes many new features, in particular:
- A new Spring expression language - SpEL allows the use of expressions which are evaluated at runtime, enabling the implementation of dynamic system elements without having to resort to writing Java code. It can be used with both the XML configuration system and with annotations.
- Extended support of annotations - Spring 3 allows annotations to be used for configuration without requiring changes to implementation classes.
- Meta annotations - These allow annotations to be created which are shortcuts to a group of annotations, allowing a @MyService annotation to expand into the service definition annotation, the scope annotation and a transaction annotation.
- REST (Representational State Transfer) support in the MVC framework. Spring 3 adds REST capabilities to Spring's MVC framework (Spring MVC). Configuration is carried out using annotations.
The framework, which was developed by VMware subsidiary SpringSource, now requires Java 5 or JDK (Java Development Kit) 1.5. This is due to the fact that JDK 1.4 has officially reached the end of its life cycle. Of largely internal interest are changes such as the use of generics in the
When first deploying a Spring 3 project, developers will notice that the
spring.jar library no longer exists. Instead, the developers have driven modularisation forward. Dependency management is now better left to other technologies such as Maven, ivy or OSGi. The Object/XML Mapping (OXM) functionality, familiar to many from the Spring Web Services project, is now included in Spring 3, as is Portlet 2.0 support from Spring MVC.
At the runtime level, the framework is compatible with Java Enterprise Edition (Java EE) version 6, released last week. The framework also supports the new JSR 330, which implements dependency injection patterns in Java.