package com.qianwen.smartman.common.utils;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.function.Function;
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import java.util.function.Predicate;
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public final class DistinctKeyUtil {
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private DistinctKeyUtil() {
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throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
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}
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public static <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) {
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ConcurrentHashMap<Object, Boolean> map = new ConcurrentHashMap<>(16);
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return t -> {
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return map.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
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};
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}
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}
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