Spring is the most widely employed framework for application development in Java enterprise edition (J2EE). It is a powerful but lightweight framework that offers features that can be used to develop any Java application. The name Spring was given to this framework to indicate a fresh start after the so-called winter of conventional J2EE. It was initially given the name Interface 21 to imply the 21st century and launched under the license of Apache 2.0. Today, Spring is extensively used in the development of Java applications. It is liked by programmers and developers mainly due to its simplicity, testability, and loose coupling features.