31 lines
974 B
Java
31 lines
974 B
Java
// onjava/BasicSupplier.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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// Supplier from a class with a zero-argument constructor
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package onjava;
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import java.util.function.*;
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import java.lang.reflect.InvocationTargetException;
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public class BasicSupplier<T> implements Supplier<T> {
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private Class<T> type;
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public BasicSupplier(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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// Assumes type is a public class:
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return type.getConstructor().newInstance();
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} catch(InstantiationException |
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NoSuchMethodException |
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InvocationTargetException |
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IllegalAccessException e) {
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throw new RuntimeException(e);
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}
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}
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// Produce a default Supplier from a type token:
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public static <T> Supplier<T> create(Class<T> type) {
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return new BasicSupplier<>(type);
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}
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}
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