Employee, first name, last name and ID

Employee, first name, last name and ID

I just started and it is really confusing because when I write my code
there is no red warning on the eclipse, however when I run the program, it
does not work. The question is: Write a program that displays employee IDs
and first and last names of employees. Use two classes. The first class
contains the employee data and separate methods to set the IDs and names.
The other class creates objects for the employees and uses the objects to
call the set methods. Create several employees and display their data. my
codes are:
public class Employee {
String lastName = null;
String firstName = null;
double ID;
public Employee(String lastName, String firstName, double ID){
this.lastName = lastName;
this.firstName = firstName;
this.ID = ID;
}
public String empStat(){
return "Last Name: " + lastName + "First Name: " + firstName + "ID" + ID;
}
}
and
public class MainEmployee {
public static void main(String args[]){
Employee nub1 = new Employee ("Griffin", "Peter", 000001);
System.out.println(nub1);
Employee nub2 = new Employee ("Griffin", "Lois", 000002);
System.out.println(nub2);
Employee nub3 = new Employee ("Griffin", "Stewie", 000003);
System.out.println(nub3);
Employee nub4 = new Employee ("Griffin", "Brian", 000004);
System.out.println(nub4);
}
}
and all it does is display Employee@523ce3f Employee@71b98cbb
Employee@4cc68351 Employee@7cd76237
can someone tell me why?