51 lines
1.4 KiB
Java
51 lines
1.4 KiB
Java
// typeinfo/Person.java
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// (c)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://OnJava8.com for more book information.
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// Using Optional with regular classes
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import onjava.*;
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import java.util.*;
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class Person {
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public final Optional<String> first;
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public final Optional<String> last;
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public final Optional<String> address;
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// etc.
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public final boolean empty;
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public
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Person(String first, String last, String address) {
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this.first = Optional.ofNullable(first);
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this.last = Optional.ofNullable(last);
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this.address = Optional.ofNullable(address);
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empty = !this.first.isPresent()
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&& !this.last.isPresent()
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&& !this.address.isPresent();
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}
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public Person(String first, String last) {
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this(first, last, null);
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}
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public Person(String last) { this(null, last, null); }
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public Person() { this(null, null, null); }
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@Override
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public String toString() {
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if(empty)
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return "<Empty>";
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return (first.orElse("") +
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" " + last.orElse("") +
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" " + address.orElse("")).trim();
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}
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public static void main(String[] args) {
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System.out.println(new Person());
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System.out.println(new Person("Smith"));
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System.out.println(new Person("Bob", "Smith"));
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System.out.println(new Person("Bob", "Smith",
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"11 Degree Lane, Frostbite Falls, MN"));
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}
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}
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/* Output:
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<Empty>
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Smith
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Bob Smith
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Bob Smith 11 Degree Lane, Frostbite Falls, MN
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*/
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