58 lines
1.4 KiB
Java
58 lines
1.4 KiB
Java
// reflection/ClassInitialization.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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import java.util.*;
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class Initable {
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static final int STATIC_FINAL = 47;
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static final int STATIC_FINAL2 =
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ClassInitialization.rand.nextInt(1000);
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static {
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System.out.println("Initializing Initable");
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}
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}
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class Initable2 {
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static int staticNonFinal = 147;
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static {
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System.out.println("Initializing Initable2");
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}
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}
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class Initable3 {
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static int staticNonFinal = 74;
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static {
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System.out.println("Initializing Initable3");
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}
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}
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public class ClassInitialization {
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public static Random rand = new Random(47);
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public static void
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main(String[] args) throws Exception {
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Class initable = Initable.class;
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System.out.println("After creating Initable ref");
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// Does not trigger initialization:
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System.out.println(Initable.STATIC_FINAL);
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// Triggers initialization:
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System.out.println(Initable.STATIC_FINAL2);
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// Triggers initialization:
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System.out.println(Initable2.staticNonFinal);
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Class initable3 = Class.forName("Initable3");
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System.out.println("After creating Initable3 ref");
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System.out.println(Initable3.staticNonFinal);
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}
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}
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/* Output:
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After creating Initable ref
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47
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Initializing Initable
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258
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Initializing Initable2
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147
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Initializing Initable3
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After creating Initable3 ref
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74
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*/
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