com.github.azbh111.utils.java.map

类 MapUtils

java.lang.Object

com.github.azbh111.utils.java.map.MapUtils

public class MapUtils
extends java.lang.Object

构造器概要

构造器

构造器和说明
MapUtils()

方法概要

限定符和类型	方法和说明
static <K,V> java.util.Map.Entry<K,V>	anyEntry(java.util.Map<K,V> statusMap)
static <K,V> K	anyKey(java.util.Map<K,V> statusMap) 取一个key
static <K,V> V	anyValue(java.util.Map<K,V> statusMap) 取一个value
static <K,V,T,R> java.util.Map<T,R>	compute(java.util.Map<K,V> src, java.util.function.BiFunction<K,V,T> keyMapper, java.util.function.BiFunction<K,V,R> valueMapper)
static <K,V,T> java.util.Map<T,V>	computeKey(java.util.Map<K,V> src, java.util.function.BiFunction<K,V,T> keyMapper)
static <K,V,R> java.util.Map<K,R>	computeValue(java.util.Map<K,V> src, java.util.function.BiFunction<K,V,R> valueMapper)
static <K,V> java.util.Map<K,V>	extract(java.util.Map<K,V> map, java.lang.Iterable<K> keys)
static <K,V> java.util.List<V>	extractValueList(java.util.Map<K,V> map, java.lang.Iterable<K> keys) 用指定keys从map中提取value,返回values
static <K,V> java.util.Set<V>	extractValueSet(java.util.Map<K,V> map, java.lang.Iterable<K> keys) 用指定keys从map中提取value,返回values
static <K,V> java.util.Map<K,V>	filter(java.util.Map<K,V> map, java.util.function.BiPredicate<K,V> test)
static <K,V> V	getOrCreate(java.util.Map<K,V> map, K key, java.util.function.Supplier<V> valueCreator)
static <K,V,GroupKey> java.util.Map<GroupKey,java.util.Map<K,V>>	groupBy(java.util.Map<K,V> map, java.util.function.BiFunction<K,V,GroupKey> groupMapper) 按给定映射,将map分成多个map
static <K,V> boolean	isNullOrEmpty(java.util.Map<K,V> map)
static <K,V> void	putAllIfAbsent(java.util.Map<K,V> src, java.util.Map<K,V> target) 遍历src,若target中不含遍历的key,则把对应的kv放入target中
static <K,V,T> void	putOrCreateAllIfAbsent(java.util.Map<K,T> src, java.util.Map<K,V> target, java.util.function.BiFunction<K,T,V> generator) 遍历src,若target中不含遍历的key,则使用generator生成v,并把kv放入target中
static <K,V> void	removeIf(java.util.Map<K,V> map, java.util.function.BiPredicate<K,V> test)
static <K,V> java.util.Map<V,K>	reverse(java.util.Map<K,V> map) 翻转map 如果翻转后key有冲突，会抛异常
static <K,V> java.util.Map<V,K>	reverse(java.util.Map<K,V> map, java.util.function.BinaryOperator<K> mergeFunction) 翻转map
static <K,V,T> java.util.List<T>	toList(java.util.Map<K,V> map, java.util.function.BiFunction<K,V,T> mapper)

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

MapUtils

public MapUtils()

方法详细资料

putAllIfAbsent

public static <K,V> void putAllIfAbsent(java.util.Map<K,V> src,
                                        java.util.Map<K,V> target)

遍历src,若target中不含遍历的key,则把对应的kv放入target中

类型参数:

K -

V -

参数:

src -

target -

putOrCreateAllIfAbsent

public static <K,V,T> void putOrCreateAllIfAbsent(java.util.Map<K,T> src,
                                                  java.util.Map<K,V> target,
                                                  java.util.function.BiFunction<K,T,V> generator)

遍历src,若target中不含遍历的key,则使用generator生成v,并把kv放入target中

类型参数:

K -

V -

T -

参数:

src -

target -

generator -

groupBy

public static <K,V,GroupKey> java.util.Map<GroupKey,java.util.Map<K,V>> groupBy(java.util.Map<K,V> map,
                                                                                java.util.function.BiFunction<K,V,GroupKey> groupMapper)

按给定映射,将map分成多个map

类型参数:

K -

V -

GroupKey -

参数:

map -

groupMapper -

返回:

toList

public static <K,V,T> java.util.List<T> toList(java.util.Map<K,V> map,
                                               java.util.function.BiFunction<K,V,T> mapper)

extract

public static <K,V> java.util.Map<K,V> extract(java.util.Map<K,V> map,
                                               java.lang.Iterable<K> keys)

extractValueList

public static <K,V> java.util.List<V> extractValueList(java.util.Map<K,V> map,
                                                       java.lang.Iterable<K> keys)

用指定keys从map中提取value,返回values

类型参数:

K -

V -

参数:

map -

keys -

返回:

extractValueSet

public static <K,V> java.util.Set<V> extractValueSet(java.util.Map<K,V> map,
                                                     java.lang.Iterable<K> keys)

用指定keys从map中提取value,返回values

类型参数:

K -

V -

参数:

map -

keys -

返回:

getOrCreate

public static <K,V> V getOrCreate(java.util.Map<K,V> map,
                                  K key,
                                  java.util.function.Supplier<V> valueCreator)

computeKey

public static <K,V,T> java.util.Map<T,V> computeKey(java.util.Map<K,V> src,
                                                    java.util.function.BiFunction<K,V,T> keyMapper)

computeValue

public static <K,V,R> java.util.Map<K,R> computeValue(java.util.Map<K,V> src,
                                                      java.util.function.BiFunction<K,V,R> valueMapper)

compute

public static <K,V,T,R> java.util.Map<T,R> compute(java.util.Map<K,V> src,
                                                   java.util.function.BiFunction<K,V,T> keyMapper,
                                                   java.util.function.BiFunction<K,V,R> valueMapper)

removeIf

public static <K,V> void removeIf(java.util.Map<K,V> map,
                                  java.util.function.BiPredicate<K,V> test)

filter

public static <K,V> java.util.Map<K,V> filter(java.util.Map<K,V> map,
                                              java.util.function.BiPredicate<K,V> test)

anyValue

public static <K,V> V anyValue(java.util.Map<K,V> statusMap)

取一个value

类型参数:

K -

V -

参数:

statusMap -

返回:

anyKey

public static <K,V> K anyKey(java.util.Map<K,V> statusMap)

取一个key

类型参数:

K -

V -

参数:

statusMap -

返回:

anyEntry

public static <K,V> java.util.Map.Entry<K,V> anyEntry(java.util.Map<K,V> statusMap)

isNullOrEmpty

public static <K,V> boolean isNullOrEmpty(java.util.Map<K,V> map)

reverse

public static <K,V> java.util.Map<V,K> reverse(java.util.Map<K,V> map)

翻转map 如果翻转后key有冲突，会抛异常

类型参数:

K -

V -

参数:

map -

返回:

reverse

public static <K,V> java.util.Map<V,K> reverse(@Nonnull
                                               java.util.Map<K,V> map,
                                               @Nullable
                                               java.util.function.BinaryOperator<K> mergeFunction)

翻转map

类型参数:

K -

V -

参数:

map -

mergeFunction - 如果不传，且key有冲突，会抛异常

返回: