35 lines
932 B
Java
35 lines
932 B
Java
// references/Immutable1.java
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// (c)2021 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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// Immutable objects are immune to aliasing
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public class Immutable1 {
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private int data;
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public Immutable1(int initVal) {
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data = initVal;
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}
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public int read() { return data; }
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public boolean nonzero() { return data != 0; }
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public Immutable1 multiply(int multiplier) {
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return new Immutable1(data * multiplier);
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}
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public static void f(Immutable1 i1) {
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Immutable1 quad = i1.multiply(4);
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System.out.println("i1 = " + i1.read());
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System.out.println("quad = " + quad.read());
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}
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public static void main(String[] args) {
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Immutable1 x = new Immutable1(47);
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System.out.println("x = " + x.read());
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f(x);
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System.out.println("x = " + x.read());
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}
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}
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/* Output:
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x = 47
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i1 = 47
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quad = 188
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x = 47
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*/
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