Struts2

Apache Struts: A brief Introduction
Apache Struts is an open-source framework used to develop Java web application. Originally developed by the rogrammer and author Craig R. McClanahan was later taken over by the Apache Software Foundation in 2002. Strutshave provided an excellent framework for developing application easily by organizing JSP and Servlet and basic java code. Strut1 with all standard Java technologies and packages of Jakarta assists in creating an extensible development environment. However, with the growing demand of web applications, Strut 1 does not stand firm and needs to be changed with the increasing demand. This led to the creation of Strut2, which are more users friendly with the features like Ajax, rapid development and extensibility.
Why Struts 2
The new version Struts 2.0 is a combination of the Sturts action framework and Webwork. According to the Struts 2.0.1 release announcement, some key features are:

Simplified Design - Programming the abstract classes instead of interfaces is one of design problem of struts1 framework that has been resolved in the struts 2 framework. Most of the Struts 2 classes are based on interfaces and most of its core interfaces are HTTP independent. Struts 2 Action classes are framework independent and are simplified to look as simple POJOs. Framework components are tried to keep loosely coupled.
Simplified Actions - Actions are simple POJOs. Any java class with execute() method can be used as an Action class. Even we don?t need to implement interfaces always. Inversion of Control is introduced while developing the action lasses. This makes the actions to be neutral to the underlying framework.