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How do we create a RESTful Root Resource Class ?

If you have some basic idea about pojo classes in java, then it will be beneficial to get good understanding. So I’ve a simple example that will give idea about pojo classes. Let see it first.
POJO is a Pure Old Java object that will not be bound by any restriction other than those forced by the Java Language Specification.
Properties of POJO classes are defined as below:-
1.     Each property must be public setter and getter methods.
2.     All instance variables within should be private.
3.     There should not extend pre-specified classes.
4.     There should not implement pre-specified interfaces.
5.     There should not contain pre-specified annotations.
6.     There must not have any argument constructors in the class.

Simple Example is as below:-
public class User
           //instance variables should be private
           private String userid;

           //public setter and getter methods
           public String getUserid() {
                      return userid;

           public void setUserid(String userid) {
                      this.userid = userid;
           //not have any argument constructors
           public User()

Thus, any one will now get good understanding to continue learning about Root resource classes.
So, Root resource classes are POJOs. There are many ways to use with annotations like it can be either annotated with @Path or have at least one method annotated with @Path or a request method designator.
request method designator is nothing but HTTP methods, which are most commonly used in a REST based architecture. They are annotated as @GET@PUT@POST, or @DELETE.
Resource methods are methods of a resource class annotated with a request method designator.
We have to first understand in this session, how to use JAX-RS to annotate Java classes to create RESTful web services.