public final class CollectionUtils extends Object
| 限定符和类型 | 方法和说明 |
|---|---|
static <T> boolean |
isEmpty(Collection<T> collection)
判断collection是否为空
|
static <K,V> boolean |
isEmpty(Map<K,V> map)
判断map是否为空
|
static <T> boolean |
isNotEmpty(Collection<T> collection)
判断collection是否不为空
|
static <K,V> boolean |
isNotEmpty(Map<K,V> map)
判断map是否不为空
|
static <T> void |
nullSafeAdd(Collection<T> collection,
T element)
为集合添加元素,并小心地处理空值
|
static <T> void |
nullSafeAddAll(Collection<T> collection,
Collection<T> elements)
为集合添加元素,并小心地处理空值
|
static <T> void |
nullSafeAddAll(Collection<T> collection,
T[] elements)
为集合添加元素,并小心地处理空值
|
static <T> int |
size(Collection<T> collection)
获取collection长度
|
static <K,V> int |
size(Map<K,V> map)
获取map长度
|
public static <T> int size(@Nullable
Collection<T> collection)
T - 集合的泛型类型collection - collection,可为 nullpublic static <K,V> int size(@Nullable
Map<K,V> map)
K - KEY类型泛型V - VALUE类型泛型map - map,可为 nullpublic static <T> boolean isEmpty(@Nullable
Collection<T> collection)
T - collection的泛型类型collection - collection,可为 nulltrue 否则返回 falsepublic static <K,V> boolean isEmpty(@Nullable
Map<K,V> map)
K - KEY类型泛型V - VALUE类型泛型map - map,可为 nulltrue 否则返回 falsepublic static <T> boolean isNotEmpty(@Nullable
Collection<T> collection)
T - collection的泛型类型collection - collection,可为 nullfalse , 否则返回 truepublic static <K,V> boolean isNotEmpty(@Nullable
Map<K,V> map)
K - KEY类型泛型V - VALUE类型泛型map - map,可为 nullfalse , 否则返回 truepublic static <T> void nullSafeAdd(Collection<T> collection, @Nullable T element)
T - 集合的泛型类型collection - 要加入的集合element - 待添加的元素public static <T> void nullSafeAddAll(Collection<T> collection, @Nullable T[] elements)
T - 集合的泛型类型collection - 要加入的集合elements - 待添加的元素public static <T> void nullSafeAddAll(Collection<T> collection, @Nullable Collection<T> elements)
T - 集合的泛型类型collection - 要加入的集合elements - 待添加的元素Copyright © 2022. All rights reserved.