CollectionUtils (Bigbird Framework 1.0.0-SNAPSHOT API)

java.lang.Object
- wang.bigbird.domain.framework.core.CollectionUtils

public class CollectionUtils
extends Object

集合操作工具类

作者:: Bigbird

方法概要

所有方法静态方法具体方法
限定符和类型	方法和说明
`static List`	`arrayToList(Object source)` Convert the supplied array into a List.
`static <E> List<List<E>>`	`batchSplit(List<E> list, int batchSize)` 将一个集合按照指定量分为多个批次
`static <E> List<List<E>>`	`batchSplitByGuava(List<E> list, int batchSize)` 将一个集合按照指定量分为多个批次
`static <E> List<List<E>>`	`batchSplitByStream(List<E> list, int batchSize)` 将一个集合按照指定量分为多个批次
`static <E> Set<E>`	`complement(Set<E> set1, Set<E> set2)` 求两个集合的非公共元素构成的集合
`static boolean`	`contains(Enumeration<?> enumeration, Object element)` Check whether the given Enumeration contains the given element.
`static boolean`	`contains(Iterator<?> iterator, Object element)` Check whether the given Iterator contains the given element.
`static boolean`	`containsAny(Collection<?> source, Collection<?> candidates)` Return `true` if any element in '`candidates`' is contained in '`source`'; otherwise returns `false`.
`static boolean`	`containsInstance(Collection<?> collection, Object element)` Check whether the given Collection contains the given element instance.
`static Class<?>`	`findCommonElementType(Collection<?> collection)` Find the common element type of the given Collection, if any.
`static <E> E`	`findFirstMatch(Collection<?> source, Collection<E> candidates)` Return the first element in '`candidates`' that is contained in '`source`'.
`static Object`	`findValueOfType(Collection<?> collection, Class<?>[] types)` Find a single value of one of the given types in the given Collection: searching the Collection for a value of the first type, then searching for a value of the second type, etc.
`static <T> T`	`findValueOfType(Collection<?> collection, Class<T> type)` Find a single value of the given type in the given Collection.
`static <T> T`	`firstElement(List<T> list)` Retrieve the first element of the given List, accessing the zero index.
`static <T> T`	`firstElement(Set<T> set)` Retrieve the first element of the given Set, using `SortedSet.first()` or otherwise using the iterator.
`static boolean`	`hasUniqueObject(Collection<?> collection)` Determine whether the given Collection only contains a single unique object.
`static <E> Set<E>`	`intersect(Set<E> set1, Set<E> set2)` 获取两个集合的交集
`static boolean`	`isEmpty(Collection<?> collection)` Return `true` if the supplied Collection is `null` or empty.
`static boolean`	`isEmpty(Map<?,?> map)` Return `true` if the supplied Map is `null` or empty.
`static boolean`	`isNotEmpty(Collection<?> collection)` 检测是否不为空
`static boolean`	`isNotEmpty(Map<?,?> map)` 检测是否不为空
`static boolean`	`isNullOrEmpty(Collection<?> c)` 判断集合是否为空
`static boolean`	`isNullOrEmpty(Map<?,?> map)` 判断集合是否为空
`static boolean`	`isNullOrEmpty(Object[] objects)` 判断集合是否为空
`static <E> boolean`	`isSubSet(Set<E> father, Set<E> child)` child是否是father的子集
`static <T> T`	`lastElement(List<T> list)` Retrieve the last element of the given List, accessing the highest index.
`static <T> T`	`lastElement(Set<T> set)` Retrieve the last element of the given Set, using `SortedSet.last()` or otherwise iterating over all elements (assuming a linked set).
`static <E> void`	`mergeArrayIntoCollection(Object array, Collection<E> collection)` Merge the given array into the given Collection.
`static <K,V> void`	`mergePropertiesIntoMap(Properties props, Map<K,V> map)` Merge the given Properties instance into the given Map, copying all properties (key-value pairs) over.
`static <E> Set<E>`	`minus(Set<E> set1, Set<E> set2)` 求两个集合的差集，set1相对set2的差集
`static <A,E extends A> A[]`	`toArray(Enumeration<E> enumeration, A[] array)` Marshal the elements from the given enumeration into an array of the given type.
`static <E> Iterator<E>`	`toIterator(Enumeration<E> enumeration)` Adapt an `Enumeration` to an `Iterator`.
`static <E> Set<E>`	`union(Set<E> set1, Set<E> set2)` 获取两个集合的并集
`static <E> Set<E>`	`unique(E[] array)` 唯一化一个数组

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 方法详细资料
  - isEmpty
```
public static boolean isEmpty(Collection<?> collection)
```
    Return true if the supplied Collection is null or empty. Otherwise, return false.
    
    参数:
    
    collection - the Collection to check
    
    返回:
    
    whether the given Collection is empty
  - isNotEmpty
```
public static boolean isNotEmpty(Collection<?> collection)
```
    检测是否不为空
    
    参数:
    
    collection - the Collection to check
    
    返回:
    
    whether the given Collection is empty
  - isEmpty
```
public static boolean isEmpty(Map<?,?> map)
```
    Return true if the supplied Map is null or empty. Otherwise, return false.
    
    参数:
    
    map - the Map to check
    
    返回:
    
    whether the given Map is empty
  - isNotEmpty
```
public static boolean isNotEmpty(Map<?,?> map)
```
    检测是否不为空
    
    参数:
    
    map - the Map to check
    
    返回:
    
    whether the given Map is empty
  - arrayToList
```
public static List arrayToList(Object source)
```
    Convert the supplied array into a List. A primitive array gets converted into a List of the appropriate wrapper type.
    NOTE: Generally prefer the standard Arrays.asList(T...) method. This arrayToList method is just meant to deal with an incoming Object value that might be an Object[] or a primitive array at runtime.
    A null source value will be converted to an empty List.
    
    参数:
    
    source - the (potentially primitive) array
    
    返回:
    
    the converted List result
    
    另请参阅:
    
    ObjectUtils.toObjectArray(Object), Arrays.asList(Object[])
  - mergeArrayIntoCollection
```
public static <E> void mergeArrayIntoCollection(Object array,
                                                Collection<E> collection)
```
    Merge the given array into the given Collection.
    
    参数:
    
    array - the array to merge (may be null)
    
    collection - the target Collection to merge the array into
  - mergePropertiesIntoMap
```
public static <K,V> void mergePropertiesIntoMap(Properties props,
                                                Map<K,V> map)
```
    Merge the given Properties instance into the given Map, copying all properties (key-value pairs) over.
    Uses Properties.propertyNames() to even catch default properties linked into the original Properties instance.
    
    参数:
    
    props - the Properties instance to merge (may be null)
    
    map - the target Map to merge the properties into
  - contains
```
public static boolean contains(Iterator<?> iterator,
                               Object element)
```
    Check whether the given Iterator contains the given element.
    
    参数:
    
    iterator - the Iterator to check
    
    element - the element to look for
    
    返回:
    
    true if found, false otherwise
  - contains
```
public static boolean contains(Enumeration<?> enumeration,
                               Object element)
```
    Check whether the given Enumeration contains the given element.
    
    参数:
    
    enumeration - the Enumeration to check
    
    element - the element to look for
    
    返回:
    
    true if found, false otherwise
  - containsInstance
```
public static boolean containsInstance(Collection<?> collection,
                                       Object element)
```
    Check whether the given Collection contains the given element instance.
    Enforces the given instance to be present, rather than returning true for an equal element as well.
    
    参数:
    
    collection - the Collection to check
    
    element - the element to look for
    
    返回:
    
    true if found, false otherwise
  - containsAny
```
public static boolean containsAny(Collection<?> source,
                                  Collection<?> candidates)
```
    Return true if any element in 'candidates' is contained in 'source'; otherwise returns false.
    
    参数:
    
    source - the source Collection
    
    candidates - the candidates to search for
    
    返回:
    
    whether any of the candidates has been found
  - findFirstMatch
```
public static <E> E findFirstMatch(Collection<?> source,
                                   Collection<E> candidates)
```
    Return the first element in 'candidates' that is contained in 'source'. If no element in 'candidates' is present in 'source' returns null. Iteration order is Collection implementation specific.
    
    参数:
    
    source - the source Collection
    
    candidates - the candidates to search for
    
    返回:
    
    the first present object, or null if not found
  - findValueOfType
```
public static <T> T findValueOfType(Collection<?> collection,
                                    Class<T> type)
```
    Find a single value of the given type in the given Collection.
    
    参数:
    
    collection - the Collection to search
    
    type - the type to look for
    
    返回:
    
    a value of the given type found if there is a clear match, or null if none or more than one such value found
  - findValueOfType
```
public static Object findValueOfType(Collection<?> collection,
                                     Class<?>[] types)
```
    Find a single value of one of the given types in the given Collection: searching the Collection for a value of the first type, then searching for a value of the second type, etc.
    
    参数:
    
    collection - the collection to search
    
    types - the types to look for, in prioritized order
    
    返回:
    
    a value of one of the given types found if there is a clear match, or null if none or more than one such value found
  - hasUniqueObject
```
public static boolean hasUniqueObject(Collection<?> collection)
```
    Determine whether the given Collection only contains a single unique object.
    
    参数:
    
    collection - the Collection to check
    
    返回:
    
    true if the collection contains a single reference or multiple references to the same instance, false otherwise
  - findCommonElementType
```
public static Class<?> findCommonElementType(Collection<?> collection)
```
    Find the common element type of the given Collection, if any.
    
    参数:
    
    collection - the Collection to check
    
    返回:
    
    the common element type, or null if no clear common type has been found (or the collection was empty)
  - firstElement
```
public static <T> T firstElement(Set<T> set)
```
    Retrieve the first element of the given Set, using SortedSet.first() or otherwise using the iterator.
    
    参数:
    
    set - the Set to check (may be null or empty)
    
    返回:
    
    the first element, or null if none
    
    从以下版本开始:
    
    5.2.3
    
    另请参阅:
    
    SortedSet, LinkedHashMap.keySet(), LinkedHashSet
  - firstElement
```
public static <T> T firstElement(List<T> list)
```
    Retrieve the first element of the given List, accessing the zero index.
    
    参数:
    
    list - the List to check (may be null or empty)
    
    返回:
    
    the first element, or null if none
    
    从以下版本开始:
    
    5.2.3
  - lastElement
```
public static <T> T lastElement(Set<T> set)
```
    Retrieve the last element of the given Set, using SortedSet.last() or otherwise iterating over all elements (assuming a linked set).
    
    参数:
    
    set - the Set to check (may be null or empty)
    
    返回:
    
    the last element, or null if none
    
    从以下版本开始:
    
    5.0.3
    
    另请参阅:
    
    SortedSet, LinkedHashMap.keySet(), LinkedHashSet
  - lastElement
```
public static <T> T lastElement(List<T> list)
```
    Retrieve the last element of the given List, accessing the highest index.
    
    参数:
    
    list - the List to check (may be null or empty)
    
    返回:
    
    the last element, or null if none
    
    从以下版本开始:
    
    5.0.3
  - toArray
```
public static <A,E extends A> A[] toArray(Enumeration<E> enumeration,
                                          A[] array)
```
    Marshal the elements from the given enumeration into an array of the given type. Enumeration elements must be assignable to the type of the given array. The array returned will be a different instance than the array given.
  - toIterator
```
public static <E> Iterator<E> toIterator(Enumeration<E> enumeration)
```
    Adapt an Enumeration to an Iterator.
    
    参数:
    
    enumeration - the original Enumeration
    
    返回:
    
    the adapted Iterator
  - isNullOrEmpty
```
public static boolean isNullOrEmpty(Collection<?> c)
```
    判断集合是否为空
    
    参数:
    
    c - 待判断集合
    
    返回:
    
    判断结果
  - isNullOrEmpty
```
public static boolean isNullOrEmpty(Map<?,?> map)
```
    判断集合是否为空
    
    参数:
    
    map - 待判断集合
    
    返回:
    
    判断结果
  - isNullOrEmpty
```
public static boolean isNullOrEmpty(Object[] objects)
```
    判断集合是否为空
    
    参数:
    
    objects - 待判断集合
    
    返回:
    
    判断结果
  - unique
```
public static <E> Set<E> unique(E[] array)
```
    唯一化一个数组
    
    类型参数:
    
    E -
    
    参数:
    
    array - 待处理数组
    
    返回:
    
    去重后的数组集合
  - isSubSet
```
public static <E> boolean isSubSet(Set<E> father,
                                   Set<E> child)
```
    child是否是father的子集
    
    类型参数:
    
    E -
    
    参数:
    
    father - 父集
    
    child - 子集
    
    返回:
    
    判断结果
  - intersect
```
public static <E> Set<E> intersect(Set<E> set1,
                                   Set<E> set2)
```
    获取两个集合的交集
    
    类型参数:
    
    E -
    
    参数:
    
    set1 - 待处理集合1
    
    set2 - 待处理集合2
    
    返回:
    
    交集
  - union
```
public static <E> Set<E> union(Set<E> set1,
                               Set<E> set2)
```
    获取两个集合的并集
    
    类型参数:
    
    E -
    
    参数:
    
    set1 - 待处理集合1
    
    set2 - 待处理集合2
    
    返回:
    
    并集
  - minus
```
public static <E> Set<E> minus(Set<E> set1,
                               Set<E> set2)
```
    求两个集合的差集，set1相对set2的差集
    
    类型参数:
    
    E -
    
    参数:
    
    set1 - 待处理集合1
    
    set2 - 待处理集合2
    
    返回:
    
    差集
  - complement
```
public static <E> Set<E> complement(Set<E> set1,
                                    Set<E> set2)
```
    求两个集合的非公共元素构成的集合
    
    类型参数:
    
    E -
    
    参数:
    
    set1 - 待处理集合1
    
    set2 - 待处理集合2
    
    返回:
    
    去交集后元素集合
  - batchSplit
```
public static <E> List<List<E>> batchSplit(List<E> list,
                                           int batchSize)
```
    将一个集合按照指定量分为多个批次
    
    类型参数:
    
    E -
    
    参数:
    
    list - 集合
    
    batchSize - 批量大小
    
    返回:
    
    按批量分配后的多个批次
  - batchSplitByStream
```
public static <E> List<List<E>> batchSplitByStream(List<E> list,
                                                   int batchSize)
```
    将一个集合按照指定量分为多个批次
    
    类型参数:
    
    E -
    
    参数:
    
    list - 集合
    
    batchSize - 批量大小
    
    返回:
    
    按批量分配后的多个批次
  - batchSplitByGuava
```
public static <E> List<List<E>> batchSplitByGuava(List<E> list,
                                                  int batchSize)
```
    将一个集合按照指定量分为多个批次
    
    类型参数:
    
    E -
    
    参数:
    
    list - 集合
    
    batchSize - 批量大小
    
    返回:
    
    按批量分配后的多个批次

类 CollectionUtils

方法概要

从类继承的方法 java.lang.Object

方法详细资料

isEmpty

isNotEmpty

isEmpty

isNotEmpty

arrayToList

mergeArrayIntoCollection

mergePropertiesIntoMap

contains

contains

containsInstance

containsAny

findFirstMatch

findValueOfType

findValueOfType

hasUniqueObject

findCommonElementType

firstElement

firstElement

lastElement

lastElement

toArray

toIterator

isNullOrEmpty

isNullOrEmpty

isNullOrEmpty

unique

isSubSet

intersect

union

minus

complement

batchSplit

batchSplitByStream

batchSplitByGuava