java.lang.Object

cloud.opencode.base.collections.ListUtil

public final class ListUtil extends Object

ListUtil - List Utility Class ListUtil - 列表工具类

Provides factory methods and operations for List implementations including ArrayList, LinkedList, and CopyOnWriteArrayList.

提供 List 实现的工厂方法和操作，包括 ArrayList、LinkedList 和 CopyOnWriteArrayList。

Features | 主要功能:

Factory methods for list creation - 列表创建工厂方法
View operations (reverse, partition, transform) - 视图操作（反转、分区、转换）
Cartesian product - 笛卡尔积
Character list from strings - 字符列表

Usage Examples | 使用示例:

// Create ArrayList - 创建 ArrayList
List<String> list = ListUtil.newArrayList("a", "b", "c");

// Reverse view - 反转视图
List<String> reversed = ListUtil.reverse(list);

// Partition - 分区
List<List<String>> partitions = ListUtil.partition(list, 2);

// Transform view - 转换视图
List<Integer> lengths = ListUtil.transform(list, String::length);

// Cartesian product - 笛卡尔积
List<List<String>> product = ListUtil.cartesianProduct(list1, list2);

Performance | 性能特性:

Factory methods: O(n) - 工厂方法: O(n)
View operations: O(1) creation, O(n) iteration - 视图操作: O(1) 创建, O(n) 遍历
Cartesian product: O(n^k) for k lists - 笛卡尔积: O(n^k) 对于 k 个列表

Security | 安全性:

Thread-safe: No (except CopyOnWriteArrayList) - 线程安全: 否（除了 CopyOnWriteArrayList）
Null-safe: Yes - 空值安全: 是

Since:

JDK 25, opencode-base-collections V1.0.0

Author:

Leon Soo www.LeonSoo.com

See Also:

Method Summary

Modifier and Type

Method

Description

static <E> List<List<E>>

cartesianProduct(List<? extends E>... lists)

Compute the Cartesian product of lists 计算笛卡尔积

static <E> List<List<E>>

cartesianProduct(List<? extends List<? extends E>> lists)

Compute the Cartesian product of lists 计算笛卡尔积

static List<Character>

charactersOf(CharSequence sequence)

Return a character list view of a CharSequence 字符列表视图

static List<Character>

charactersOf(String string)

Return a character list view of a string 字符列表视图

static <E> ArrayList<E>

newArrayList()

Create a new ArrayList 创建 ArrayList

static <E> ArrayList<E>

newArrayList(E... elements)

Create a new ArrayList with initial elements 创建带初始元素的 ArrayList

static <E> ArrayList<E>

newArrayList(Iterable<? extends E> elements)

Create a new ArrayList from an Iterable 从 Iterable 创建 ArrayList

static <E> ArrayList<E>

newArrayListWithCapacity(int initialCapacity)

Create a new ArrayList with initial capacity 创建指定容量的 ArrayList

static <E> ArrayList<E>

newArrayListWithExpectedSize(int expectedSize)

Create a new ArrayList with expected size 创建预期大小的 ArrayList

static <E> CopyOnWriteArrayList<E>

newCopyOnWriteArrayList()

Create a new CopyOnWriteArrayList 创建 CopyOnWriteArrayList

static <E> CopyOnWriteArrayList<E>

newCopyOnWriteArrayList(Iterable<? extends E> elements)

Create a new CopyOnWriteArrayList from an Iterable 从 Iterable 创建 CopyOnWriteArrayList

static <E> LinkedList<E>

newLinkedList()

Create a new LinkedList 创建 LinkedList

static <E> LinkedList<E>

newLinkedList(Iterable<? extends E> elements)

Create a new LinkedList from an Iterable 从 Iterable 创建 LinkedList

static <E> List<List<E>>

partition(List<E> list, int size)

Return a partitioned view of the list 分区视图

static <E> List<E>

reverse(List<E> list)

Return a reversed view of the list 反转视图

static <F,T> List<T>

transform(List<F> fromList, Function<? super F, ? extends T> function)

Return a transformed view of the list 转换视图

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- newArrayList
  
  public static <E> ArrayList<E> newArrayList()
  
  Create a new ArrayList 创建 ArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Returns:
  
  new ArrayList | 新的 ArrayList
- newArrayList
  
  @SafeVarargs public static <E> ArrayList<E> newArrayList(E... elements)
  
  Create a new ArrayList with initial elements 创建带初始元素的 ArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  elements - initial elements | 初始元素
  
  Returns:
  
  new ArrayList | 新的 ArrayList
- newArrayList
  
  public static <E> ArrayList<E> newArrayList(Iterable<? extends E> elements)
  
  Create a new ArrayList from an Iterable 从 Iterable 创建 ArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  elements - elements | 元素
  
  Returns:
  
  new ArrayList | 新的 ArrayList
- newArrayListWithCapacity
  
  public static <E> ArrayList<E> newArrayListWithCapacity(int initialCapacity)
  
  Create a new ArrayList with initial capacity 创建指定容量的 ArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  initialCapacity - initial capacity | 初始容量
  
  Returns:
  
  new ArrayList | 新的 ArrayList
- newArrayListWithExpectedSize
  
  public static <E> ArrayList<E> newArrayListWithExpectedSize(int expectedSize)
  
  Create a new ArrayList with expected size 创建预期大小的 ArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  expectedSize - expected size | 预期大小
  
  Returns:
  
  new ArrayList | 新的 ArrayList
- newLinkedList
  
  public static <E> LinkedList<E> newLinkedList()
  
  Create a new LinkedList 创建 LinkedList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Returns:
  
  new LinkedList | 新的 LinkedList
- newLinkedList
  
  public static <E> LinkedList<E> newLinkedList(Iterable<? extends E> elements)
  
  Create a new LinkedList from an Iterable 从 Iterable 创建 LinkedList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  elements - elements | 元素
  
  Returns:
  
  new LinkedList | 新的 LinkedList
- newCopyOnWriteArrayList
  
  public static <E> CopyOnWriteArrayList<E> newCopyOnWriteArrayList()
  
  Create a new CopyOnWriteArrayList 创建 CopyOnWriteArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Returns:
  
  new CopyOnWriteArrayList | 新的 CopyOnWriteArrayList
- newCopyOnWriteArrayList
  
  public static <E> CopyOnWriteArrayList<E> newCopyOnWriteArrayList(Iterable<? extends E> elements)
  
  Create a new CopyOnWriteArrayList from an Iterable 从 Iterable 创建 CopyOnWriteArrayList
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  elements - elements | 元素
  
  Returns:
  
  new CopyOnWriteArrayList | 新的 CopyOnWriteArrayList
- reverse
  
  public static <E> List<E> reverse(List<E> list)
  
  Return a reversed view of the list 反转视图
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list | 列表
  
  Returns:
  
  reversed view | 反转视图
- partition
  
  public static <E> List<List<E>> partition(List<E> list, int size)
  
  Return a partitioned view of the list 分区视图
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list | 列表
  
  size - partition size | 分区大小
  
  Returns:
  
  list of partitions | 分区列表
- transform
  
  public static <F,T> List<T> transform(List<F> fromList, Function<? super F, ? extends T> function)
  
  Return a transformed view of the list 转换视图
  
  Type Parameters:
  
  F - from type | 源类型
  
  T - to type | 目标类型
  
  Parameters:
  
  fromList - the source list | 源列表
  
  function - the transform function | 转换函数
  
  Returns:
  
  transformed view | 转换视图
- charactersOf
  
  public static List<Character> charactersOf(String string)
  
  Return a character list view of a string 字符列表视图
  
  Parameters:
  
  string - the string | 字符串
  
  Returns:
  
  character list | 字符列表
- charactersOf
  
  public static List<Character> charactersOf(CharSequence sequence)
  
  Return a character list view of a CharSequence 字符列表视图
  
  Parameters:
  
  sequence - the CharSequence | 字符序列
  
  Returns:
  
  character list | 字符列表
- cartesianProduct
  
  public static <E> List<List<E>> cartesianProduct(List<? extends List<? extends E>> lists)
  
  Compute the Cartesian product of lists 计算笛卡尔积
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  lists - lists to compute product | 要计算积的列表
  
  Returns:
  
  Cartesian product | 笛卡尔积
- cartesianProduct
  
  @SafeVarargs public static <E> List<List<E>> cartesianProduct(List<? extends E>... lists)
  
  Compute the Cartesian product of lists 计算笛卡尔积
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  lists - lists to compute product | 要计算积的列表
  
  Returns:
  
  Cartesian product | 笛卡尔积

Class ListUtil

Method Summary

Methods inherited from class Object

Method Details

newArrayList

newArrayList

newArrayList

newArrayListWithCapacity

newArrayListWithExpectedSize

newLinkedList

newLinkedList

newCopyOnWriteArrayList

newCopyOnWriteArrayList

reverse

partition

transform

charactersOf

charactersOf

cartesianProduct

cartesianProduct