Velocity is a open source tool for web applications which allows as to easily create and render documents that format and present your data. It focuses on two Main areas:
Servlet-based WWW development.
General application use.
Velocity provides a Class called VelocityServlet by which the developer can use it as a super class for the servlets in his web applications which provides additional support and offer a utility class to help with application development.
Primarily used to develop dynamic, servlet-based Websites, Velocity's clean separation of template and Java code makes it ideal for Model 2-style Model-View-Controller (MVC) Web development. As a general template engine, Velocity suits many other purposes, such as code generation, XML generation and transformation, and textual stream processing. Velocity is useful in any Java application area that requires data formatting and presentation.
You should use Velocity for the following reasons:
It adapts to many application areas.
It offers a simple, clear syntax for the template designer.
It offers a simple programming model for the developer.
Because templates and code are separate, you can develop and maintain them independently.
The Velocity engine easily integrates into any Java application environment, especially
servlets.
Velocity enables templates to access any public method of data objects in the context.
Velocity can be used with Servlet based technologies such as servlet,jsp for manipulate and presents the data to the end user effectively.
Velocity lets us to write the code and design the template in parallel. The
designer integrates the data into the nondata presentation content (like images, text, and so on) in the template.
Velocity has built-in mathematical functions that can be used in templates with the set directive.
Velocity Features:
It's easy to use, both for designers and programmers .
It separates your presentation formatting from your code.
It lets you use your existing classes as they are.
It's portable and works in any Java application.
It's free and the source code.
Represent the same data with different Template(Views).