Drop the variables from your subclass so they don't shadow the variables with the same name in the parent class.
//sub class
public class Customer extends Main.Customer {
//DROP THESE private String Name, Address, Phone, Email, Company;
public Customer(String Name, String Address, String Phone, String Email, String Company) {
super(Name, Address, Phone, Email, Company);
}
}
And add getters to your parent class:
//parent class
public abstract class Customer {
private String Name, Address, Phone, Email, Company;
public static final int NAME = 0, ADDRESS = 1, PHONE = 2, EMAIL = 3, COMPANY = 4;
public Customer(String Name, String Address, String Phone, String Email, String Company) {
setValues(Name, Address, Phone, Email, Company);
}
private void setValues(String Name, String Address, String Phone, String Email, String Company) {
setName(Name);
setAddress(Address);
setPhone(Phone);
setEmail(Email);
setCompany(Company);
}
public String getName() {
return Name;
}
public String getAddress() {
return Address;
}
//etc....
}
Also, I really recommend using different names for your parent and subclass to avoid confusion.