Apache Click is a Web application framework for Java language and built top of Java Servlet API. Its free and open source project under Apache foundation.
In the new version of Apache Click (version 2.3.0) it add some new features like AJAX support, Page Actions and stateful controls. Using Apache click we can build a web applications without using JSPs and MCV architecture.
Apache click use HTML templates an POJO for develop applications. It also include some unit testing features.
Ref : Apache Click Home
: Getting Started with apache click