package com.userdb;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class userData {
    public String name;
    public int iduser;

    public userData(){}


    public userData(String name, int iduser) {
        this.name = name;
        this.iduser = iduser;
    }


    public String getName() {
        return name;
    }
    public int getIduser() {
        return iduser;
    }
    public void setName(String name) {
        this.name = name;
    }
    public void setIduser(int iduser) {
        this.iduser = iduser;
    }


}

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;


@Path("/resttest")
public class airtime {
    ResultSet rs=null;
    String msg="hello";
    Connection con=null;


    @GET
    @Produces(MediaType.APPLICATION_XML)
    @Path("/get_users")
    public List<userData> get_users(){
        List<userData> retUser=new ArrayList<>();
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con=DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "");
            System.out.println("DriveManager");
        PreparedStatement     ps=con.prepareStatement("SELECT * FROM users");
            rs=ps.executeQuery();
            System.out.println(rs);
            while(rs.next()){
                userData obj=new userData();
                obj.setIduser(rs.getInt("iduser"));
                obj.setName(rs.getString("name"));
            retUser.add(obj);
                System.out.println("userData obj added to list");
                }
            con.close();

        } catch (Exception e){
            e.printStackTrace();
        }
        return retUser;
        }
}

<servlet>
  <servlet-name>Jersey WebService</servlet-name>
  <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
  <init-param>
  <param-name>jersey.config.server.provider.packages</param-name>
  <param-value>com.userdb</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
  <servlet-name>Jersey WebService</servlet-name>
  <url-pattern>/api/*</url-pattern>
  </servlet-mapping>

</web-app>