30 lines
863 B
Java
30 lines
863 B
Java
// typeinfo/Person.java
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// ©2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// A class with a Null Object.
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import onjava.*;
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class Person {
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public final String first;
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public final String last;
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public final String address;
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// etc.
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public Person(String first, String last, String address){
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this.first = first;
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this.last = last;
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this.address = address;
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}
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@Override
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public String toString() {
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return "Person: " + first + " " + last + " " + address;
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}
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public static class NullPerson
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extends Person implements Null {
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private NullPerson() { super("None", "None", "None"); }
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@Override
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public String toString() { return "NullPerson"; }
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}
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public static final Person NULL = new NullPerson();
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}
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