CollectionUtils.java
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package cn.iocoder.dashboard.util.collection;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.collection.CollectionUtil;
import java.util.*;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.Collectors;
/**
* Collection 工具类
*
* @author 芋道源码
*/
public class CollectionUtils {
public static boolean containsAny(Object source, Object... targets) {
return Arrays.asList(targets).contains(source);
}
public static boolean isAnyEmpty(Collection<?>... collections) {
return Arrays.stream(collections).anyMatch(CollectionUtil::isEmpty);
}
public static <T> List<T> filterList(Collection<T> from, Predicate<T> predicate) {
if (CollUtil.isEmpty(from)) {
return new ArrayList<>();
}
return from.stream().filter(predicate).collect(Collectors.toList());
}
public static <T, R> List<T> distinct(Collection<T> from, Function<T, R> keyMapper) {
if (CollUtil.isEmpty(from)) {
return new ArrayList<>();
}
return distinct(from, keyMapper, (t1, t2) -> t1);
}
public static <T, R> List<T> distinct(Collection<T> from, Function<T, R> keyMapper, BinaryOperator<T> cover) {
if (CollUtil.isEmpty(from)) {
return new ArrayList<>();
}
return new ArrayList<>(convertMap(from, keyMapper, Function.identity(), cover).values());
}
public static <T, U> List<U> convertList(Collection<T> from, Function<T, U> func) {
if (CollUtil.isEmpty(from)) {
return new ArrayList<>();
}
return from.stream().map(func).collect(Collectors.toList());
}
public static <T, U> Set<U> convertSet(Collection<T> from, Function<T, U> func) {
if (CollUtil.isEmpty(from)) {
return new HashSet<>();
}
return from.stream().map(func).collect(Collectors.toSet());
}
public static <T, K> Map<K, T> convertMap(Collection<T> from, Function<T, K> keyFunc) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return convertMap(from, keyFunc, Function.identity());
}
public static <T, K> Map<K, T> convertMap(Collection<T> from, Function<T, K> keyFunc, Supplier<? extends Map<K, T>> supplier) {
if (CollUtil.isEmpty(from)) {
return supplier.get();
}
return convertMap(from, keyFunc, Function.identity(), supplier);
}
public static <T, K, V> Map<K, V> convertMap(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return convertMap(from, keyFunc, valueFunc, (v1, v2) -> v1);
}
public static <T, K, V> Map<K, V> convertMap(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc, BinaryOperator<V> mergeFunction) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return convertMap(from, keyFunc, valueFunc, mergeFunction, HashMap::new);
}
public static <T, K, V> Map<K, V> convertMap(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc, Supplier<? extends Map<K, V>> supplier) {
if (CollUtil.isEmpty(from)) {
return supplier.get();
}
return convertMap(from, keyFunc, valueFunc, (v1, v2) -> v1, supplier);
}
public static <T, K, V> Map<K, V> convertMap(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc, BinaryOperator<V> mergeFunction, Supplier<? extends Map<K, V>> supplier) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return from.stream().collect(Collectors.toMap(keyFunc, valueFunc, mergeFunction, supplier));
}
public static <T, K> Map<K, List<T>> convertMultiMap(Collection<T> from, Function<T, K> keyFunc) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return from.stream().collect(Collectors.groupingBy(keyFunc, Collectors.mapping(t -> t, Collectors.toList())));
}
public static <T, K, V> Map<K, List<V>> convertMultiMap(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return from.stream()
.collect(Collectors.groupingBy(keyFunc, Collectors.mapping(valueFunc, Collectors.toList())));
}
// 暂时没想好名字，先以 2 结尾噶
public static <T, K, V> Map<K, Set<V>> convertMultiMap2(Collection<T> from, Function<T, K> keyFunc, Function<T, V> valueFunc) {
if (CollUtil.isEmpty(from)) {
return new HashMap<>();
}
return from.stream().collect(Collectors.groupingBy(keyFunc, Collectors.mapping(valueFunc, Collectors.toSet())));
}
public static boolean containsAny(Collection<?> source, Collection<?> candidates) {
return org.springframework.util.CollectionUtils.containsAny(source, candidates);
}
public static <T> T getFirst(List<T> from) {
return !CollectionUtil.isEmpty(from) ? from.get(0) : null;
}
public static <T> T findFirst(List<T> from, Predicate<T> predicate) {
if (CollUtil.isEmpty(from)) {
return null;
}
return from.stream().filter(predicate).findFirst().orElse(null);
}
public static <T> void addIfNotNull(Collection<T> coll, T item) {
if (item == null) {
return;
}
coll.add(item);
}
}