public interface CollectableStream<T> extends Stream<T>
Stream.collect(Collector)使用Collector中一些常用方法Stream.Builder<T>| 限定符和类型 | 方法和说明 |
|---|---|
default <K> Map<K,List<T>> |
group(Function<? super T,? extends K> classifier)
通过给定分组依据进行分组
|
default <K,A,D> Map<K,D> |
group(Function<? super T,? extends K> classifier,
Collector<? super T,A,D> downstream)
通过给定分组依据进行分组
|
default <K,D,A,M extends Map<K,D>> |
group(Function<? super T,? extends K> classifier,
Supplier<M> mapFactory,
Collector<? super T,A,D> downstream)
通过给定分组依据进行分组
|
default String |
join()
返回拼接后的字符串
|
default String |
join(CharSequence delimiter)
返回拼接后的字符串
|
default String |
join(CharSequence delimiter,
CharSequence prefix,
CharSequence suffix)
返回拼接后的字符串
|
default Map<Boolean,List<T>> |
partition(Predicate<T> predicate)
根据给定判断条件分组
|
default <R> Map<Boolean,R> |
partition(Predicate<T> predicate,
Collector<T,?,R> downstream)
根据给定判断条件分组
|
default <C extends Collection<T>> |
partition(Predicate<T> predicate,
Supplier<C> collFactory)
根据给定判断条件分组
|
default <C extends Collection<T>> |
toCollection(Supplier<C> collectionFactory)
转换成集合
|
default Map<Integer,T> |
toIdxMap()
转换为map,key为下标,value为元素
|
default <U> Map<Integer,U> |
toIdxMap(Function<? super T,? extends U> valueMapper)
转换为map,key为下标,value为给定操作执行后的返回值
|
default List<T> |
toList()
转换为
ArrayList |
default <K> Map<K,T> |
toMap(Function<? super T,? extends K> keyMapper)
转换为map,key为给定操作执行后的返回值,value为当前元素
|
default <K,U> Map<K,U> |
toMap(Function<? super T,? extends K> keyMapper,
Function<? super T,? extends U> valueMapper)
转换为map,key,value为给定操作执行后的返回值
|
default <K,U> Map<K,U> |
toMap(Function<? super T,? extends K> keyMapper,
Function<? super T,? extends U> valueMapper,
BinaryOperator<U> mergeFunction)
转换为map,key,value为给定操作执行后的返回值
|
default <K,U,M extends Map<K,U>> |
toMap(Function<? super T,? extends K> keyMapper,
Function<? super T,? extends U> valueMapper,
BinaryOperator<U> mergeFunction,
Supplier<M> mapSupplier)
转换为map,key,value为给定操作执行后的返回值
|
default Set<T> |
toSet()
转换为HashSet
|
default List<T> |
toUnmodifiableList()
换为不可变集合
|
default <K,U> Map<K,U> |
toUnmodifiableMap(Function<? super T,? extends K> keyMapper,
Function<? super T,? extends U> valueMapper)
转换为不可变map,key,value为给定操作执行后的返回值
|
default <K,U> Map<K,U> |
toUnmodifiableMap(Function<? super T,? extends K> keyMapper,
Function<? super T,? extends U> valueMapper,
BinaryOperator<U> mergeFunction)
转换为不可变map,key,value为给定操作执行后的返回值
|
default Set<T> |
toUnmodifiableSet()
换为不可变集合
|
default <R> Map<T,R> |
toZip(Iterable<R> other)
与给定的可迭代对象转换成map,key为现有元素,value为给定可迭代对象迭代的元素
至少包含全部的key,如果对应位置上的value不存在,则为null |
allMatch, anyMatch, builder, collect, collect, concat, count, distinct, empty, filter, findAny, findFirst, flatMap, flatMapToDouble, flatMapToInt, flatMapToLong, forEach, forEachOrdered, generate, iterate, limit, map, mapToDouble, mapToInt, mapToLong, max, min, noneMatch, of, of, peek, reduce, reduce, reduce, skip, sorted, sorted, toArray, toArrayclose, isParallel, iterator, onClose, parallel, sequential, spliterator, unordereddefault String join()
default String join(CharSequence delimiter)
delimiter - 分隔符default String join(CharSequence delimiter, CharSequence prefix, CharSequence suffix)
delimiter - 分隔符prefix - 前缀suffix - 后缀default <C extends Collection<T>> C toCollection(Supplier<C> collectionFactory)
C - 集合类型collectionFactory - 集合工厂(可以是集合构造器)default <K> Map<K,T> toMap(Function<? super T,? extends K> keyMapper)
K - key类型keyMapper - 指定的key操作default <K,U> Map<K,U> toMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)
K - key类型U - value类型keyMapper - 指定的key操作valueMapper - 指定value操作default <U> Map<Integer,U> toIdxMap(Function<? super T,? extends U> valueMapper)
U - value类型valueMapper - 指定value操作default <K,U> Map<K,U> toUnmodifiableMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)
K - key类型U - value类型keyMapper - 指定的key操作valueMapper - 指定value操作default <K,U> Map<K,U> toMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, BinaryOperator<U> mergeFunction)
K - key类型U - value类型keyMapper - 指定的key操作valueMapper - 指定value操作mergeFunction - 合并操作default <K,U> Map<K,U> toUnmodifiableMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, BinaryOperator<U> mergeFunction)
K - key类型U - value类型keyMapper - 指定的key操作valueMapper - 指定value操作mergeFunction - 合并操作default <K,U,M extends Map<K,U>> M toMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, BinaryOperator<U> mergeFunction, Supplier<M> mapSupplier)
K - key类型U - value类型M - map类型keyMapper - 指定的key操作valueMapper - 指定value操作mergeFunction - 合并操作mapSupplier - map工厂default <R> Map<T,R> toZip(Iterable<R> other)
R - 可迭代对象迭代的元素类型other - 可迭代对象default <K> Map<K,List<T>> group(Function<? super T,? extends K> classifier)
K - 实体中的分组依据对应类型,也是Map中key的类型classifier - 分组依据default <K,A,D> Map<K,D> group(Function<? super T,? extends K> classifier, Collector<? super T,A,D> downstream)
K - 实体中的分组依据对应类型,也是Map中key的类型D - 下游操作对应返回类型,也是Map中value的类型A - 下游操作在进行中间操作时对应类型classifier - 分组依据downstream - 下游操作default <K,D,A,M extends Map<K,D>> M group(Function<? super T,? extends K> classifier, Supplier<M> mapFactory, Collector<? super T,A,D> downstream)
K - 实体中的分组依据对应类型,也是Map中key的类型D - 下游操作对应返回类型,也是Map中value的类型A - 下游操作在进行中间操作时对应类型M - 最后返回结果Map类型classifier - 分组依据mapFactory - 提供的mapdownstream - 下游操作default Map<Boolean,List<T>> partition(Predicate<T> predicate)
predicate - 判断条件default <C extends Collection<T>> Map<Boolean,C> partition(Predicate<T> predicate, Supplier<C> collFactory)
C - a C classpredicate - 判断条件collFactory - 提供的集合Copyright © 2023 dromara. All rights reserved.