org.example.common.util

类 StreamUtils

java.lang.Object

org.example.common.util.StreamUtils

public class StreamUtils
extends Object

stream 流工具类

作者:

Lion Li

构造器概要

构造器

构造器和说明
StreamUtils()

方法概要

限定符和类型	方法和说明
static <E> List<E>	filter(Collection<E> collection, Predicate<E> function)
static <E,T,U> Map<T,Map<U,E>>	group2Map(Collection<E> collection, Function<E,T> key1, Function<E,U> key2)
static <E,K,U> Map<K,Map<U,List<E>>>	groupBy2Key(Collection<E> collection, Function<E,K> key1, Function<E,U> key2)
static <E,K> Map<K,List<E>>	groupByKey(Collection<E> collection, Function<E,K> key)
static <E> String	join(Collection<E> collection, Function<E,String> function)
static <E> String	join(Collection<E> collection, Function<E,String> function, CharSequence delimiter)
static <K,X,Y,V> Map<K,V>	merge(Map<K,X> map1, Map<K,Y> map2, BiFunction<X,Y,V> merge)
static <E> List<E>	sorted(Collection<E> collection, Comparator<E> comparing)
static <V,K> Map<K,V>	toIdentityMap(Collection<V> collection, Function<V,K> key)
static <E,T> List<T>	toList(Collection<E> collection, Function<E,T> function)
static <E,K,V> Map<K,V>	toMap(Collection<E> collection, Function<E,K> key, Function<E,V> value)
static <E,T> Set<T>	toSet(Collection<E> collection, Function<E,T> function)

从类继承的方法 java.lang.Object

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

构造器详细资料

StreamUtils

public StreamUtils()

方法详细资料

filter

public static <E> List<E> filter(Collection<E> collection,
                                 Predicate<E> function)

join

public static <E> String join(Collection<E> collection,
                              Function<E,String> function)

join

public static <E> String join(Collection<E> collection,
                              Function<E,String> function,
                              CharSequence delimiter)

sorted

public static <E> List<E> sorted(Collection<E> collection,
                                 Comparator<E> comparing)

toIdentityMap

public static <V,K> Map<K,V> toIdentityMap(Collection<V> collection,
                                           Function<V,K> key)

toMap

public static <E,K,V> Map<K,V> toMap(Collection<E> collection,
                                     Function<E,K> key,
                                     Function<E,V> value)

groupByKey

public static <E,K> Map<K,List<E>> groupByKey(Collection<E> collection,
                                              Function<E,K> key)

groupBy2Key

public static <E,K,U> Map<K,Map<U,List<E>>> groupBy2Key(Collection<E> collection,
                                                        Function<E,K> key1,
                                                        Function<E,U> key2)

group2Map

public static <E,T,U> Map<T,Map<U,E>> group2Map(Collection<E> collection,
                                                Function<E,T> key1,
                                                Function<E,U> key2)

toList

public static <E,T> List<T> toList(Collection<E> collection,
                                   Function<E,T> function)

toSet

public static <E,T> Set<T> toSet(Collection<E> collection,
                                 Function<E,T> function)

merge

public static <K,X,Y,V> Map<K,V> merge(Map<K,X> map1,
                                       Map<K,Y> map2,
                                       BiFunction<X,Y,V> merge)