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Merge branch 'v5-dev' of gitee.com:dromara/hutool into v5-dev

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Looly 2022-01-08 18:48:25 +08:00
commit 8d33235eef
2 changed files with 75 additions and 13 deletions
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16
hutool-core/src/main/java/cn/hutool/core/collection/CollStreamUtil.java
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@ -3,16 +3,10 @@ package cn.hutool.core.collection;
import cn.hutool.core.lang.Opt;
import cn.hutool.core.map.MapUtil;
import cn.hutool.core.stream.CollectorUtil;
import cn.hutool.core.stream.StreamUtil;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.*;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.stream.Collector;
@ -161,7 +155,7 @@ public class CollStreamUtil {
if (CollUtil.isEmpty(collection)) {
return Collections.emptyMap();
}
return groupBy(collection, key1, Collectors.groupingBy(key2, Collectors.toList()), isParallel);
return groupBy(collection, key1, CollectorUtil.groupingBy(key2, Collectors.toList()), isParallel);
}
/**
@ -236,7 +230,7 @@ public class CollStreamUtil {
if (CollUtil.isEmpty(collection)) {
return Collections.emptyMap();
}
return groupBy(collection, key, Collectors.mapping(value, Collectors.toList()), isParallel);
return groupBy(collection, key, Collectors.mapping(v -> Opt.ofNullable(v).map(value).orElse(null), Collectors.toList()), isParallel);
}
/**
@ -276,7 +270,7 @@ public class CollStreamUtil {
if (CollUtil.isEmpty(collection)) {
return Collections.emptyMap();
}
return StreamUtil.of(collection, isParallel).collect(Collectors.groupingBy(key, downstream));
return StreamUtil.of(collection, isParallel).collect(CollectorUtil.groupingBy(key, downstream));
}
/**

72
hutool-core/src/main/java/cn/hutool/core/stream/CollectorUtil.java
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@ -2,9 +2,11 @@ package cn.hutool.core.stream;
import cn.hutool.core.util.StrUtil;
import java.util.Collections;
import java.util.StringJoiner;
import java.util.*;
import java.util.function.BiConsumer;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collector;
/**
@ -61,4 +63,70 @@ public class CollectorUtil {
Collections.emptySet()
);
}
/**
* 提供对null值友好的groupingBy操作的{@link Collector}实现，可指定map类型
*
* @param classifier 分组依据
* @param mapFactory 提供的map
* @param downstream 下游操作
* @param <T> 实体类型
* @param <K> 实体中的分组依据对应类型，也是Map中key的类型
* @param <D> 下游操作对应返回类型，也是Map中value的类型
* @param <A> 下游操作在进行中间操作时对应类型
* @param <M> 最后返回结果Map类型
* @return {@link Collector}
*/
public static <T, K, D, A, M extends Map<K, D>> Collector<T, ?, M> groupingBy(Function<? super T, ? extends K> classifier,
Supplier<M> mapFactory,
Collector<? super T, A, D> downstream) {
Supplier<A> downstreamSupplier = downstream.supplier();
BiConsumer<A, ? super T> downstreamAccumulator = downstream.accumulator();
BiConsumer<Map<K, A>, T> accumulator = (m, t) -> {
K key = Optional.ofNullable(t).map(classifier).orElse(null);
A container = m.computeIfAbsent(key, k -> downstreamSupplier.get());
downstreamAccumulator.accept(container, t);
};
BinaryOperator<Map<K, A>> merger = (m1, m2) -> {
for (Map.Entry<K, A> e : m2.entrySet()) {
m1.merge(e.getKey(), e.getValue(), downstream.combiner());
}
return m1;
};
@SuppressWarnings("unchecked")
Supplier<Map<K, A>> mangledFactory = (Supplier<Map<K, A>>) mapFactory;
if (downstream.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
return new SimpleCollector<>(mangledFactory, accumulator, merger, Collections.unmodifiableSet(EnumSet.of(Collector.Characteristics.IDENTITY_FINISH)));
} else {
@SuppressWarnings("unchecked")
Function<A, A> downstreamFinisher = (Function<A, A>) downstream.finisher();
Function<Map<K, A>, M> finisher = intermediate -> {
intermediate.replaceAll((k, v) -> downstreamFinisher.apply(v));
@SuppressWarnings("unchecked")
M castResult = (M) intermediate;
return castResult;
};
return new SimpleCollector<>(mangledFactory, accumulator, merger, finisher, Collections.emptySet());
}
}
/**
* 提供对null值友好的groupingBy操作的{@link Collector}实现
*
* @param classifier 分组依据
* @param downstream 下游操作
* @param <T> 实体类型
* @param <K> 实体中的分组依据对应类型，也是Map中key的类型
* @param <D> 下游操作对应返回类型，也是Map中value的类型
* @param <A> 下游操作在进行中间操作时对应类型
* @return {@link Collector}
*/
public static <T, K, A, D>
Collector<T, ?, Map<K, D>> groupingBy(Function<? super T, ? extends K> classifier,
Collector<? super T, A, D> downstream) {
return groupingBy(classifier, HashMap::new, downstream);
}
}