org.apache.shenyu.common.utils

Class ListUtil

java.lang.Object

org.apache.shenyu.common.utils.ListUtil

public final class ListUtil
extends java.lang.Object

ListUtil.

Method Summary

Modifier and Type	Method and Description
static <T> java.util.List<T>	castList(java.util.List<?> list, java.lang.Class<T> clazz) cast list.
static <R,T> java.util.List<T>	castList(java.util.List<R> list, java.util.function.Function<R,T> mapper) cast list.
static <T> java.util.List<T>	emptyIsDefault(java.util.List<T> list, java.util.List<T> defaultV) if list is empty, return default value.
static <R> R	findFirst(java.util.List<R> list, java.util.function.Function<R,java.lang.Boolean> function) list map. if element is null it filter.
static <K,U> java.util.Map<K,java.util.List<U>>	groupBy(java.util.Collection<U> list, java.util.function.Function<? super U,? extends K> function) list group by. if element is null it filters.
static <T> java.util.List<T>	list(T... t) list.
static <R,T> java.util.List<T>	map(java.util.Collection<R> list, java.util.function.Function<? super R,? extends T> function) list map. if element is null it filter.
static <T> java.util.List<T>	merge(java.util.List<T> list1, java.util.List<T> list2) merge.
static <T> java.util.Set<T>	mergeSet(java.util.Set<T> set1, java.util.Set<T> set2) merge.
static <T> java.util.List<T>	of(T... t) new array list.
static <K,U,T> java.util.Map<K,U>	toMap(java.util.Collection<T> list, java.util.function.Function<? super T,? extends K> keyMapper, java.util.function.Function<? super T,? extends U> valueMapper) list to map. if element is null it filters.
static <K,U> java.util.Map<K,U>	toMap(java.util.Collection<U> list, java.util.function.Function<? super U,? extends K> function) list to map. if element is null it filters.

Methods inherited from class java.lang.Object

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

Method Detail

list

@SafeVarargs
public static <T> java.util.List<T> list(T... t)

list.

Type Parameters:

T - type

Parameters:

t - e

Returns:

list

of

@SafeVarargs
public static <T> java.util.List<T> of(T... t)

new array list.

Type Parameters:

T - type

Parameters:

t - e

Returns:

unmodifiable list

emptyIsDefault

public static <T> java.util.List<T> emptyIsDefault(java.util.List<T> list,
                                                   java.util.List<T> defaultV)

if list is empty, return default value.

Type Parameters:

T - list type

Parameters:

list - list

defaultV - default value

Returns:

default value or list

map

public static <R,T> java.util.List<T> map(java.util.Collection<R> list,
                                          java.util.function.Function<? super R,? extends T> function)

list map.
if element is null it filter.

Type Parameters:

R - resource type

T - target type

Parameters:

list - list

function - map fun

Returns:

list

findFirst

public static <R> R findFirst(java.util.List<R> list,
                              java.util.function.Function<R,java.lang.Boolean> function)

list map.
if element is null it filter.

Type Parameters:

R - resource type

Parameters:

list - list

function - map fun

Returns:

list

toMap

public static <K,U> java.util.Map<K,U> toMap(java.util.Collection<U> list,
                                             java.util.function.Function<? super U,? extends K> function)

list to map.
if element is null it filters.

Type Parameters:

K - map key type

U - map value type

Parameters:

list - list

function - map fun

Returns:

list

toMap

public static <K,U,T> java.util.Map<K,U> toMap(java.util.Collection<T> list,
                                               java.util.function.Function<? super T,? extends K> keyMapper,
                                               java.util.function.Function<? super T,? extends U> valueMapper)

list to map.
if element is null it filters.

Type Parameters:

K - map key type

U - map value type

T - list value type

Parameters:

list - list

keyMapper - map key convert

valueMapper - map value convert

Returns:

list

groupBy

public static <K,U> java.util.Map<K,java.util.List<U>> groupBy(java.util.Collection<U> list,
                                                               java.util.function.Function<? super U,? extends K> function)

list group by.
if element is null it filters.

Type Parameters:

K - map key type

U - map value type

Parameters:

list - list

function - group key fun

Returns:

list

mergeSet

public static <T> java.util.Set<T> mergeSet(java.util.Set<T> set1,
                                            java.util.Set<T> set2)

merge.

Type Parameters:

T - type

Parameters:

set1 - merge to.

set2 - merge from.

Returns:

collection1

merge

public static <T> java.util.List<T> merge(java.util.List<T> list1,
                                          java.util.List<T> list2)

merge.

Type Parameters:

T - type

Parameters:

list1 - list1

list2 - list2

Returns:

list1

castList

public static <T> java.util.List<T> castList(java.util.List<?> list,
                                             java.lang.Class<T> clazz)

cast list.

Type Parameters:

T - the type parameter

Parameters:

list - collections

clazz - class type

Returns:

the result

castList

public static <R,T> java.util.List<T> castList(java.util.List<R> list,
                                               java.util.function.Function<R,T> mapper)

cast list.

Type Parameters:

R - the source type parameter

T - the target type parameter

Parameters:

list - list

mapper - mapper

Returns:

the result