模块 iofairy.falcon

程序包 com.iofairy.falcon.stream

类 CollectorKit

java.lang.Object

com.iofairy.falcon.stream.CollectorKit

public class CollectorKit
extends Object

Collector Kit

从以下版本开始:

0.4.1

字段概要

字段

限定符和类型	字段	说明
static Collector.Characteristics[]	CH_ALL
static Collector.Characteristics[]	CH_CONCURRENT
static Collector.Characteristics[]	CH_CONCURRENT_ID
static Collector.Characteristics[]	CH_CONCURRENT_UNORDERED
static Collector.Characteristics[]	CH_EMPTY
static Collector.Characteristics[]	CH_ID
static Collector.Characteristics[]	CH_UNORDERED
static Collector.Characteristics[]	CH_UNORDERED_ID

构造器概要

构造器

限定符	构造器	说明
private	CollectorKit()

方法概要

限定符和类型	方法	说明
static <T,K> Collector<T,?,Map<K,List<T>>>	groupingByAllowNullKey(Function<? super T,? extends K> classifier)	创建一个Map分组收集器，允许key为null
private static void	throwDuplicateKeyException(Object key)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toConcurrentMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toConcurrentMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, boolean isAllowDuplicateKeys)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toLinkedMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toLinkedMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, boolean isAllowDuplicateKeys)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, boolean isAllowDuplicateKeys)
static <T,K,U,M extends Map<K,U>> Collector<T,?,M>	toMap(Supplier<M> mapSupplier, Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, boolean isAllowDuplicateKeys)	创建一个Map收集器

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

CH_ALL

public static final Collector.Characteristics[] CH_ALL

CH_CONCURRENT_UNORDERED

public static final Collector.Characteristics[] CH_CONCURRENT_UNORDERED

CH_CONCURRENT_ID

public static final Collector.Characteristics[] CH_CONCURRENT_ID

CH_UNORDERED_ID

public static final Collector.Characteristics[] CH_UNORDERED_ID

CH_CONCURRENT

public static final Collector.Characteristics[] CH_CONCURRENT

CH_UNORDERED

public static final Collector.Characteristics[] CH_UNORDERED

CH_ID

public static final Collector.Characteristics[] CH_ID

CH_EMPTY

public static final Collector.Characteristics[] CH_EMPTY

构造器详细资料

CollectorKit

private CollectorKit()

方法详细资料

groupingByAllowNullKey

public static <T,K> Collector<T,?,Map<K,List<T>>> groupingByAllowNullKey(Function<? super T,? extends K> classifier)

创建一个Map分组收集器，允许key为null

类型参数:

T - Stream流中的元素类型

K - Map的Key的类型

参数:

classifier - 分类器

返回:

Map收集器

toMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toMap(Supplier<M> mapSupplier,
                                                                Function<? super T,? extends K> keyMapper,
                                                                Function<? super T,? extends U> valueMapper,
                                                                boolean isAllowDuplicateKeys)

创建一个Map收集器

类型参数:

T - Stream流中的元素类型

K - Map的Key的类型

U - Map的Value的类型

M - Map

参数:

mapSupplier - map对象提供

keyMapper - map key的映射器

valueMapper - map value的映射器

isAllowDuplicateKeys - 是否允许相同的 key，如果 false，遇到相同的 key，抛出异常；如果 true，遇到相同的 key，则会覆盖

返回:

Map收集器

抛出:

IllegalStateException - 如果参数isAllowDuplicateKeys为 true 且转换过程存在相同的key，则抛出此异常

toMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toMap(Function<? super T,? extends K> keyMapper,
                                                                Function<? super T,? extends U> valueMapper)

toMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toMap(Function<? super T,? extends K> keyMapper,
                                                                Function<? super T,? extends U> valueMapper,
                                                                boolean isAllowDuplicateKeys)

toLinkedMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toLinkedMap(Function<? super T,? extends K> keyMapper,
                                                                      Function<? super T,? extends U> valueMapper)

toLinkedMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toLinkedMap(Function<? super T,? extends K> keyMapper,
                                                                      Function<? super T,? extends U> valueMapper,
                                                                      boolean isAllowDuplicateKeys)

toConcurrentMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toConcurrentMap(Function<? super T,? extends K> keyMapper,
                                                                          Function<? super T,? extends U> valueMapper)

toConcurrentMap

public static <T,K,U,M extends Map<K,U>> Collector<T,?,M> toConcurrentMap(Function<? super T,? extends K> keyMapper,
                                                                          Function<? super T,? extends U> valueMapper,
                                                                          boolean isAllowDuplicateKeys)

throwDuplicateKeyException

private static void throwDuplicateKeyException(Object key)