Plain Old Java Object, referred to as POJO, is an ordinary Java object, not bound by any particular restriction other than those forced by the Java Language Specification and not requiring any classpath. The term POJO was coined by Martin Fowler (American Software Developer) in 2000. Available in Java from EJB 3.0 via sun microsystem.
The POJO class does not have a structural and methodological design meeting, nor is it bound to any Java Framework and can be used by any Java program. These are used for increasing the readability and re-usability of a program due to their easy maintenance and easy-to-read and write features.
Typically, the POJO class contains variables as well as their Getters and Setters. POJO classes are like beans as both are used to describe objects in order to increase readability and reusability, although POJO files have no special restrictions.
We often need to convert Java objects into JSON so that we can easily understand them. To convert a Java object into a JSON object, we have the following two methods: