Initial commit

wangrong

2026-08-30 4c949c0dc9bcae785c281c9d8125295f09810b15

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package io.dataease.utils;
 
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
 
public class DeCollectionUtils {
    public static <K, V> Map<K, List<V>> groupBy(List<V> list,
                                                 Function<V, K> keyExtractor) {
        if (list == null || list.isEmpty()) {
            return new HashMap<>();
        }
        return list.stream()
                .filter(item -> keyExtractor.apply(item) != null)
                .collect(Collectors.groupingBy(keyExtractor));
    }
}