37 lines
815 B
Java
37 lines
815 B
Java
//: access/Lunch.java
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// Demonstrates class access specifiers. Make a class
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// effectively private with private constructors:
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class Soup1 {
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private Soup1() {}
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// (1) Allow creation via static method:
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public static Soup1 makeSoup() {
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return new Soup1();
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}
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}
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class Soup2 {
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private Soup2() {}
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// (2) Create a static object and return a reference
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// upon request.(The "Singleton" pattern):
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private static Soup2 ps1 = new Soup2();
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public static Soup2 access() {
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return ps1;
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}
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public void f() {}
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}
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// Only one public class allowed per file:
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public class Lunch {
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void testPrivate() {
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// Can't do this! Private constructor:
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//! Soup1 soup = new Soup1();
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}
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void testStatic() {
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Soup1 soup = Soup1.makeSoup();
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}
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void testSingleton() {
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Soup2.access().f();
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}
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} ///:~
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