程序包 net.dongliu.commons.collection

类 Lists

java.lang.Object

net.dongliu.commons.collection.Lists

public class Lists
extends java.lang.Object

Utils method for List

构造器概要

构造器

构造器	说明
Lists()

方法概要

修饰符和类型	方法	说明
static <T> java.util.List<T>	concat(java.util.List<? extends T> list1, java.util.List<? extends T> list2, java.util.List<? extends T>... otherLists)	Concat multi lists, to one new immutable List.
static <T> java.util.List<T>	concat(java.util.List<T> list1, java.util.List<T> list2)	Concat two lists, to one new immutable list.
static <S,T> java.util.List<T>	convert(java.util.List<S> list, java.util.function.Function<? super S,? extends T> mapper)	Convert origin list to new immutable List, the elements are converted by mapper.
static <S,T> java.util.List<T>	convertTo(java.util.List<S> list, java.util.function.Function<? super S,? extends T> mapper)	已过时。 use convert(List, Function)
static <T> java.util.List<T>	copy(java.util.List<T> list)	Return a new immutable list equals the origin list
static <T> java.util.List<T>	copyOf(java.util.List<T> list)	Return a new immutable list equals the origin list
static <T> java.util.List<T>	filter(java.util.List<T> list, java.util.function.Predicate<? super T> predicate)	Filter list, return a new list which contains the elements in origin list which accepted by predicate.
static <T> java.util.Optional<T>	find(java.util.List<T> list, java.util.function.Predicate<? super T> predicate)	Fetch the first element accepted by predicate in list.
static <T> @Nullable T	findOrNull(java.util.List<T> list, java.util.function.Predicate<? super T> predicate)	Fetch the first element accepted by predicate in list.
static <T> java.util.Optional<T>	first(java.util.List<T> list)	Fetch the first element of list.
static <T> @Nullable T	firstOrNull(java.util.List<T> list)	Fetch the first element of list.
static <T> void	forEachIndexed(java.util.List<T> list, IndexedConsumer<? super T> consumer)	Traverse on a list, with index for each element.
static <T> void	forEachLastAware(java.util.List<T> list, LastAwareConsumer<? super T> consumer)	Traverse on a list.
static <T> T	getOneExactly(java.util.List<T> list)	Return the element in list, if list has one and only one element.
static <T> java.util.Optional<T>	last(java.util.List<T> list)	Fetch the last element of list.
static <T> java.util.ArrayList<T>	newArrayList()	Create new empty ArrayList
static <T> java.util.ArrayList<T>	newArrayList(T v)	Create new ArrayList.
static <T> java.util.ArrayList<T>	newArrayList(T... values)	Create new array List.
static <T> java.util.ArrayList<T>	newArrayList(T v1, T v2)	Create new ArrayList.
static <T> java.util.ArrayList<T>	newArrayList(T v1, T v2, T v3)	Create new ArrayList.
static <T> java.util.ArrayList<T>	newArrayList(T v1, T v2, T v3, T v4)	Create new ArrayList.
static <T> java.util.ArrayList<T>	newArrayList(T v1, T v2, T v3, T v4, T v5)	Create new ArrayList.
static <T,R extends java.util.List<T>> R	newList(java.util.function.Supplier<R> supplier, T... values)	For easy list creation with initial values.
static <T> java.util.List<T>	nullToEmpty(@Nullable java.util.List<T> list)	If list is null, return immutable empty list; else return list self.
static <T> java.util.List<T>	of()	Create new immutable empty List
static <T> java.util.List<T>	of(T v)	Create new immutable List.
static <T> java.util.List<T>	of(T... values)	Create new immutable List.
static <T> java.util.List<T>	of(T v1, T v2)	Create new immutable List.
static <T> java.util.List<T>	of(T v1, T v2, T v3)	Create new immutable List.
static <T> java.util.List<T>	of(T v1, T v2, T v3, T v4)	Create new immutable List.
static <T> java.util.List<T>	of(T v1, T v2, T v3, T v4, T v5)	Create new immutable List.
static <T> java.util.List<T>	of(T v1, T v2, T v3, T v4, T v5, T v6)	Create new immutable List.
static <T> PartitionResult<java.util.List<T>>	partition(java.util.List<T> list, java.util.function.Predicate<? super T> predicate)	Divide list to two immutable Lists, the first list contains elements accepted by predicate, the other contains other elements.
static <T> java.util.List<T>	randomAccessed(java.util.Collection<T> c)	If collection is random access list, return it self; else return a new random access list contains the element from collection.
static <T> java.util.List<T>	reverse(java.util.List<T> list)	Return a new reversed immutable List.
static <T> java.util.Optional<T>	reverseFind(java.util.List<T> list, java.util.function.Predicate<? super T> predicate)	Fetch the last element of list.
static <T,R extends java.lang.Comparable<R>> java.util.List<T>	sort(java.util.List<? extends T> list, java.util.function.Function<? super T,R> comparator)	Return a new sorted immutable List, the element is compared by comparator.
static <T extends java.lang.Comparable<T>> java.util.List<T>	sort(java.util.List<T> list)	Return a new sorted immutable List.
static <T> java.util.List<java.util.List<T>>	split(java.util.List<T> list, int subSize)	Split list, into multi subLists, each subList has the specified subSize, except the last one.
static <T> T[]	toArray(java.util.List<? extends T> list, java.util.function.IntFunction<T[]> maker)	已过时。 using Collection.toArray(IntFunction)

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

Lists

public Lists()

方法详细资料

nullToEmpty

public static <T> java.util.List<T> nullToEmpty(@Nullable java.util.List<T> list)

If list is null, return immutable empty list; else return list self.

类型参数:

T - the element type

参数:

list - the list

返回:

non-null list

newArrayList

public static <T> java.util.ArrayList<T> newArrayList()

Create new empty ArrayList

newArrayList

public static <T> java.util.ArrayList<T> newArrayList(T v)

Create new ArrayList.

newArrayList

public static <T> java.util.ArrayList<T> newArrayList(T v1,
                                                      T v2)

Create new ArrayList.

newArrayList

public static <T> java.util.ArrayList<T> newArrayList(T v1,
                                                      T v2,
                                                      T v3)

Create new ArrayList.

newArrayList

public static <T> java.util.ArrayList<T> newArrayList(T v1,
                                                      T v2,
                                                      T v3,
                                                      T v4)

Create new ArrayList.

newArrayList

public static <T> java.util.ArrayList<T> newArrayList(T v1,
                                                      T v2,
                                                      T v3,
                                                      T v4,
                                                      T v5)

Create new ArrayList.

newArrayList

@SafeVarargs
public static <T> java.util.ArrayList<T> newArrayList(T... values)

Create new array List.

newList

@SafeVarargs
public static <T,R extends java.util.List<T>> R newList(java.util.function.Supplier<R> supplier,
                                                              T... values)

For easy list creation with initial values.

类型参数:

T - element type

参数:

supplier - the list supplier

values - the elements to add into list

返回:

the list

of

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

Create new immutable empty List

of

public static <T> java.util.List<T> of(T v)

Create new immutable List.

of

public static <T> java.util.List<T> of(T v1,
                                       T v2)

Create new immutable List.

of

public static <T> java.util.List<T> of(T v1,
                                       T v2,
                                       T v3)

Create new immutable List.

of

public static <T> java.util.List<T> of(T v1,
                                       T v2,
                                       T v3,
                                       T v4)

Create new immutable List.

of

public static <T> java.util.List<T> of(T v1,
                                       T v2,
                                       T v3,
                                       T v4,
                                       T v5)

Create new immutable List.

of

public static <T> java.util.List<T> of(T v1,
                                       T v2,
                                       T v3,
                                       T v4,
                                       T v5,
                                       T v6)

Create new immutable List.

of

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

Create new immutable List.

copy

public static <T> java.util.List<T> copy(java.util.List<T> list)

Return a new immutable list equals the origin list

参数:

list - cannot be null

copyOf

public static <T> java.util.List<T> copyOf(java.util.List<T> list)

Return a new immutable list equals the origin list

参数:

list - cannot be null

convert

public static <S,T> java.util.List<T> convert(java.util.List<S> list,
                                                    java.util.function.Function<? super S,? extends T> mapper)

Convert origin list to new immutable List, the elements are converted by mapper.

参数:

mapper - function to convert elements

返回:

list contains the result.

convertTo

@Deprecated
public static <S,T> java.util.List<T> convertTo(java.util.List<S> list,
                                                      java.util.function.Function<? super S,? extends T> mapper)

已过时。

use convert(List, Function)

Convert origin list to new immutable List, the elements are converted by specific function.

参数:

mapper - function to convert elements

返回:

list contains the result.

filter

public static <T> java.util.List<T> filter(java.util.List<T> list,
                                           java.util.function.Predicate<? super T> predicate)

Filter list, return a new list which contains the elements in origin list which accepted by predicate.

返回:

new list

reverse

public static <T> java.util.List<T> reverse(java.util.List<T> list)

Return a new reversed immutable List.

类型参数:

T - the element type

参数:

list - the list

返回:

reversed List

sort

public static <T,R extends java.lang.Comparable<R>> java.util.List<T> sort(java.util.List<? extends T> list,
                                                                                 java.util.function.Function<? super T,R> comparator)

Return a new sorted immutable List, the element is compared by comparator.

类型参数:

T - the element type

参数:

list - the list

comparator - the function to get Comparable values from list elements.

返回:

sorted List

sort

public static <T extends java.lang.Comparable<T>> java.util.List<T> sort(java.util.List<T> list)

Return a new sorted immutable List.

类型参数:

T - the element type

参数:

list - the list

返回:

sorted List

concat

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

Concat two lists, to one new immutable list.

类型参数:

T - element type

参数:

list1 - list1

list2 - list2

返回:

new List

concat

@SafeVarargs
public static <T> java.util.List<T> concat(java.util.List<? extends T> list1,
                                           java.util.List<? extends T> list2,
                                           java.util.List<? extends T>... otherLists)

Concat multi lists, to one new immutable List.

类型参数:

T - element type

参数:

list1 - list1 first List to concat

list2 - list2 second List to concat

otherLists - other lists to concat

返回:

new List

split

public static <T> java.util.List<java.util.List<T>> split(java.util.List<T> list,
                                                          int subSize)

Split list, into multi subLists, each subList has the specified subSize, except the last one.

返回:

List of SubLists

partition

public static <T> PartitionResult<java.util.List<T>> partition(java.util.List<T> list,
                                                               java.util.function.Predicate<? super T> predicate)

Divide list to two immutable Lists, the first list contains elements accepted by predicate, the other contains other elements.

参数:

list - can not be null

返回:

two list

getOneExactly

public static <T> T getOneExactly(java.util.List<T> list)
                           throws java.util.NoSuchElementException,
                                  TooManyElementsException

Return the element in list, if list has one and only one element. Throw an exception otherwise.

抛出:

java.util.NoSuchElementException - if iterable has no element

TooManyElementsException - if iterable has more than one element

first

public static <T> java.util.Optional<T> first(java.util.List<T> list)

Fetch the first element of list. The element should not be null, or NullPointerException will be thrown.

参数:

list - can not be null

返回:

Optional

firstOrNull

public static <T> @Nullable T firstOrNull(java.util.List<T> list)

Fetch the first element of list.

参数:

list - can not be null

返回:

The first element. If list is empty, return null.

last

public static <T> java.util.Optional<T> last(java.util.List<T> list)

Fetch the last element of list. The element should not be null, or NullPointerException will be thrown.

参数:

list - can not be null

返回:

Optional

find

public static <T> java.util.Optional<T> find(java.util.List<T> list,
                                             java.util.function.Predicate<? super T> predicate)

Fetch the first element accepted by predicate in list. The element should not be null, or NullPointerException will be thrown.

参数:

list - can not be null

返回:

Optional

findOrNull

public static <T> @Nullable T findOrNull(java.util.List<T> list,
                                         java.util.function.Predicate<? super T> predicate)

Fetch the first element accepted by predicate in list.

参数:

list - can not be null

返回:

The first accepted element. If list is empty, return null.

reverseFind

public static <T> java.util.Optional<T> reverseFind(java.util.List<T> list,
                                                    java.util.function.Predicate<? super T> predicate)

Fetch the last element of list. The element should not be null, or NullPointerException will be thrown.

参数:

list - can not be null

返回:

Optional

toArray

@Deprecated
public static <T> T[] toArray(java.util.List<? extends T> list,
                              java.util.function.IntFunction<T[]> maker)

已过时。

using Collection.toArray(IntFunction)

Convert list to array. This method using method reference, work better than the API in Collection. Call this method as:

     List<String> list = Lists.of("1", "2", "3");
     String[] array = Lists.toArray(list, String[]::new);
 

类型参数:

T - element type

参数:

list - the list

maker - create the target array

返回:

the target array containing elements in collection

forEachLastAware

public static <T> void forEachLastAware(java.util.List<T> list,
                                        LastAwareConsumer<? super T> consumer)

Traverse on a list.

类型参数:

T - the data type

参数:

list - the list

consumer - the consumer

forEachIndexed

public static <T> void forEachIndexed(java.util.List<T> list,
                                      IndexedConsumer<? super T> consumer)

Traverse on a list, with index for each element.

类型参数:

T - the data type

参数:

list - the list

consumer - the consumer

randomAccessed

public static <T> java.util.List<T> randomAccessed(java.util.Collection<T> c)

If collection is random access list, return it self; else return a new random access list contains the element from collection. There is not guaranty whether returned list is immutable or not.

类型参数:

T - the element type

参数:

c - the list

返回:

a random accessed list