46 lines
1.0 KiB
Java
46 lines
1.0 KiB
Java
// reflection/DynamicSupplier.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.function.*;
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import java.util.stream.*;
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class ID {
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private static long counter;
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private final long id = counter++;
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@Override public String toString() {
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return Long.toString(id);
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}
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// A public default constructor is required
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// to call getConstructor().newInstance():
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public ID() {}
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}
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public class DynamicSupplier<T> implements Supplier<T> {
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private Class<T> type;
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public DynamicSupplier(Class<T> type) {
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this.type = type;
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}
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@Override public T get() {
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try {
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return type.getConstructor().newInstance();
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} catch(Exception e) {
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throw new RuntimeException(e);
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}
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}
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public static void main(String[] args) {
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Stream.generate(
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new DynamicSupplier<>(ID.class))
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.skip(10)
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.limit(5)
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.forEach(System.out::println);
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}
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}
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/* Output:
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10
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11
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12
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13
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14
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*/
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