//: typeinfo/Person.java // ©2015 MindView LLC: see Copyright.txt // A class with a Null Object. import net.mindview.util.*; class Person { public final String first; public final String last; public final String address; // etc. public Person(String first, String last, String address){ this.first = first; this.last = last; this.address = address; } @Override public String toString() { return "Person: " + first + " " + last + " " + address; } public static class NullPerson extends Person implements Null { private NullPerson() { super("None", "None", "None"); } @Override public String toString() { return "NullPerson"; } } public static final Person NULL = new NullPerson(); } ///:~