java.lang.Object

cloud.opencode.base.collections.immutable.ImmutableCollectionUtil

public final class ImmutableCollectionUtil extends Object

ImmutableCollectionUtil - Utility Class for Immutable Collections ImmutableCollectionUtil - 不可变集合工具类

Provides utility methods for working with immutable collections, including transformation, combination, and conversion operations.

提供用于处理不可变集合的工具方法，包括转换、组合和转换操作。

Features | 主要功能:

Collection transformation - 集合转换
Collection combination - 集合组合
Type conversion - 类型转换
Filtering and mapping - 过滤和映射
Null-safe operations - 空值安全操作

Usage Examples | 使用示例:

// Transform list - 转换列表
ImmutableList<String> strings = ImmutableList.of("1", "2", "3");
ImmutableList<Integer> integers = ImmutableCollectionUtil.transform(strings, Integer::parseInt);

// Combine lists - 组合列表
ImmutableList<String> list1 = ImmutableList.of("a", "b");
ImmutableList<String> list2 = ImmutableList.of("c", "d");
ImmutableList<String> combined = ImmutableCollectionUtil.concat(list1, list2);

// Convert to multiset - 转换为多重集
ImmutableList<String> list = ImmutableList.of("a", "b", "a", "c");
ImmutableMultiset<String> multiset = ImmutableCollectionUtil.toMultiset(list);

// Create BiMap from map - 从映射创建双向映射
Map<String, Integer> map = Map.of("one", 1, "two", 2);
ImmutableBiMap<String, Integer> bimap = ImmutableCollectionUtil.toBiMap(map);

Performance | 性能特性:

Most operations: O(n) where n is input size - 大多数操作: O(n)，其中n是输入大小
Null checks: O(1) - 空值检查: O(1)
Type conversions: O(n) - 类型转换: O(n)

Security | 安全性:

Thread-safe: Yes (all methods) - 线程安全: 是（所有方法）
Null-safe: Yes (all methods) - 空值安全: 是（所有方法）

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> ImmutableMultiset<E>

combine(ImmutableMultiset<? extends E>... multisets)

Combine multiple multisets.

static <E> ImmutableList<E>

concat(ImmutableList<? extends E>... lists)

Concatenate multiple lists into one.

static <E> ImmutableSet<E>

difference(ImmutableSet<E> set1, ImmutableSet<E> set2)

Difference of two sets (elements in set1 but not in set2).

static <E> ImmutableList<E>

filter(ImmutableList<E> list, Predicate<? super E> predicate)

Filter a list based on a predicate.

static <E> ImmutableSet<E>

filter(ImmutableSet<E> set, Predicate<? super E> predicate)

Filter a set based on a predicate.

static <E> ImmutableSet<E>

intersection(ImmutableSet<E> set1, ImmutableSet<E> set2)

Intersection of two sets.

static boolean

isNullOrEmpty(ImmutableTable<?,?,?> table)

Check if a table is null or empty.

static boolean

isNullOrEmpty(Collection<?> collection)

Check if a collection is null or empty.

static boolean

isNullOrEmpty(Map<?,?> map)

Check if a map is null or empty.

static <E> ImmutableList<E>

reverse(ImmutableList<E> list)

Reverse a list.

static <E> ImmutableList<E>

subList(ImmutableList<E> list, int fromIndex, int toIndex)

Get a sublist.

static <K,V> ImmutableBiMap<K,V>

toBiMap(Map<? extends K, ? extends V> map)

Convert a map to an immutable bimap.

static <E> ImmutableList<E>

toList(ImmutableMultiset<E> multiset)

Convert an immutable multiset to an immutable list (preserving duplicates).

static <E> ImmutableList<E>

toList(ImmutableSet<E> set)

Convert an immutable set to an immutable list.

static <E> ImmutableMultiset<E>

toMultiset(Collection<? extends E> collection)

Convert a collection to an immutable multiset.

static <E> ImmutableSet<E>

toSet(ImmutableList<E> list)

Convert an immutable list to an immutable set.

static <R,C,V> ImmutableTable<R,C,V>

toTable(Map<? extends R, ? extends Map<? extends C, ? extends V>> nestedMap)

Create a table from a nested map.

static <T,R> ImmutableMultiset<R>

transform(ImmutableMultiset<T> multiset, Function<? super T, ? extends R> function)

Transform a multiset using a mapping function.

static <T,R> ImmutableList<R>

transform(ImmutableList<T> list, Function<? super T, ? extends R> function)

Transform a list using a mapping function.

static <T,R> ImmutableSet<R>

transform(ImmutableSet<T> set, Function<? super T, ? extends R> function)

Transform a set using a mapping function.

static <R,C,V> ImmutableTable<C,R,V>

transpose(ImmutableTable<R,C,V> table)

Transpose a table (swap rows and columns).

static <E> ImmutableSet<E>

union(ImmutableSet<? extends E>... sets)

Union of multiple sets.

static <K,V> ImmutableBiMap<K,V>

zipToBiMap(List<? extends K> keys, List<? extends V> values)

Create a bimap from two lists (keys and values).

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

Method Details
- transform
  
  public static <T,R> ImmutableList<R> transform(ImmutableList<T> list, Function<? super T, ? extends R> function)
  
  Transform a list using a mapping function. 使用映射函数转换列表。
  
  Type Parameters:
  
  T - source element type | 源元素类型
  
  R - target element type | 目标元素类型
  
  Parameters:
  
  list - the list to transform | 要转换的列表
  
  function - the mapping function | 映射函数
  
  Returns:
  
  transformed immutable list | 转换后的不可变列表
- concat
  
  @SafeVarargs public static <E> ImmutableList<E> concat(ImmutableList<? extends E>... lists)
  
  Concatenate multiple lists into one. 将多个列表连接为一个。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  lists - the lists to concatenate | 要连接的列表
  
  Returns:
  
  concatenated immutable list | 连接后的不可变列表
- reverse
  
  public static <E> ImmutableList<E> reverse(ImmutableList<E> list)
  
  Reverse a list. 反转列表。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list to reverse | 要反转的列表
  
  Returns:
  
  reversed immutable list | 反转后的不可变列表
- subList
  
  public static <E> ImmutableList<E> subList(ImmutableList<E> list, int fromIndex, int toIndex)
  
  Get a sublist. 获取子列表。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list | 列表
  
  fromIndex - the start index (inclusive) | 起始索引（包含）
  
  toIndex - the end index (exclusive) | 结束索引（不包含）
  
  Returns:
  
  sublist as immutable list | 作为不可变列表的子列表
- transform
  
  public static <T,R> ImmutableSet<R> transform(ImmutableSet<T> set, Function<? super T, ? extends R> function)
  
  Transform a set using a mapping function. 使用映射函数转换集合。
  
  Type Parameters:
  
  T - source element type | 源元素类型
  
  R - target element type | 目标元素类型
  
  Parameters:
  
  set - the set to transform | 要转换的集合
  
  function - the mapping function | 映射函数
  
  Returns:
  
  transformed immutable set | 转换后的不可变集合
- union
  
  @SafeVarargs public static <E> ImmutableSet<E> union(ImmutableSet<? extends E>... sets)
  
  Union of multiple sets. 多个集合的并集。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  sets - the sets to union | 要合并的集合
  
  Returns:
  
  union as immutable set | 作为不可变集合的并集
- intersection
  
  public static <E> ImmutableSet<E> intersection(ImmutableSet<E> set1, ImmutableSet<E> set2)
  
  Intersection of two sets. 两个集合的交集。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  set1 - the first set | 第一个集合
  
  set2 - the second set | 第二个集合
  
  Returns:
  
  intersection as immutable set | 作为不可变集合的交集
- difference
  
  public static <E> ImmutableSet<E> difference(ImmutableSet<E> set1, ImmutableSet<E> set2)
  
  Difference of two sets (elements in set1 but not in set2). 两个集合的差集（在set1中但不在set2中的元素）。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  set1 - the first set | 第一个集合
  
  set2 - the second set | 第二个集合
  
  Returns:
  
  difference as immutable set | 作为不可变集合的差集
- toMultiset
  
  public static <E> ImmutableMultiset<E> toMultiset(Collection<? extends E> collection)
  
  Convert a collection to an immutable multiset. 将集合转换为不可变多重集。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  collection - the collection | 集合
  
  Returns:
  
  immutable multiset | 不可变多重集
- transform
  
  public static <T,R> ImmutableMultiset<R> transform(ImmutableMultiset<T> multiset, Function<? super T, ? extends R> function)
  
  Transform a multiset using a mapping function. 使用映射函数转换多重集。
  
  Type Parameters:
  
  T - source element type | 源元素类型
  
  R - target element type | 目标元素类型
  
  Parameters:
  
  multiset - the multiset to transform | 要转换的多重集
  
  function - the mapping function | 映射函数
  
  Returns:
  
  transformed immutable multiset | 转换后的不可变多重集
- combine
  
  @SafeVarargs public static <E> ImmutableMultiset<E> combine(ImmutableMultiset<? extends E>... multisets)
  
  Combine multiple multisets. 组合多个多重集。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  multisets - the multisets to combine | 要组合的多重集
  
  Returns:
  
  combined immutable multiset | 组合后的不可变多重集
- toBiMap
  
  public static <K,V> ImmutableBiMap<K,V> toBiMap(Map<? extends K, ? extends V> map)
  
  Convert a map to an immutable bimap. 将映射转换为不可变双向映射。
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Parameters:
  
  map - the map | 映射
  
  Returns:
  
  immutable bimap | 不可变双向映射
  
  Throws:
  
  OpenCollectionException - if duplicate values are found | 如果找到重复值
- zipToBiMap
  
  public static <K,V> ImmutableBiMap<K,V> zipToBiMap(List<? extends K> keys, List<? extends V> values)
  
  Create a bimap from two lists (keys and values). 从两个列表（键和值）创建双向映射。
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Parameters:
  
  keys - the keys | 键
  
  values - the values | 值
  
  Returns:
  
  immutable bimap | 不可变双向映射
  
  Throws:
  
  OpenCollectionException - if lists have different sizes or duplicate keys/values | 如果列表大小不同或有重复的键/值
- toTable
  
  public static <R,C,V> ImmutableTable<R,C,V> toTable(Map<? extends R, ? extends Map<? extends C, ? extends V>> nestedMap)
  
  Create a table from a nested map. 从嵌套映射创建表格。
  
  Type Parameters:
  
  R - row key type | 行键类型
  
  C - column key type | 列键类型
  
  V - value type | 值类型
  
  Parameters:
  
  nestedMap - the nested map (row -> column -> value) | 嵌套映射（行 -> 列 -> 值）
  
  Returns:
  
  immutable table | 不可变表格
- transpose
  
  public static <R,C,V> ImmutableTable<C,R,V> transpose(ImmutableTable<R,C,V> table)
  
  Transpose a table (swap rows and columns). 转置表格（交换行和列）。
  
  Type Parameters:
  
  R - row key type | 行键类型
  
  C - column key type | 列键类型
  
  V - value type | 值类型
  
  Parameters:
  
  table - the table to transpose | 要转置的表格
  
  Returns:
  
  transposed immutable table | 转置后的不可变表格
- toSet
  
  public static <E> ImmutableSet<E> toSet(ImmutableList<E> list)
  
  Convert an immutable list to an immutable set. 将不可变列表转换为不可变集合。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list | 列表
  
  Returns:
  
  immutable set | 不可变集合
- toList
  
  public static <E> ImmutableList<E> toList(ImmutableSet<E> set)
  
  Convert an immutable set to an immutable list. 将不可变集合转换为不可变列表。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  set - the set | 集合
  
  Returns:
  
  immutable list | 不可变列表
- toList
  
  public static <E> ImmutableList<E> toList(ImmutableMultiset<E> multiset)
  
  Convert an immutable multiset to an immutable list (preserving duplicates). 将不可变多重集转换为不可变列表（保留重复项）。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  multiset - the multiset | 多重集
  
  Returns:
  
  immutable list with duplicates | 带重复项的不可变列表
- filter
  
  public static <E> ImmutableList<E> filter(ImmutableList<E> list, Predicate<? super E> predicate)
  
  Filter a list based on a predicate. 基于谓词过滤列表。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  list - the list to filter | 要过滤的列表
  
  predicate - the filter predicate | 过滤谓词
  
  Returns:
  
  filtered immutable list | 过滤后的不可变列表
- filter
  
  public static <E> ImmutableSet<E> filter(ImmutableSet<E> set, Predicate<? super E> predicate)
  
  Filter a set based on a predicate. 基于谓词过滤集合。
  
  Type Parameters:
  
  E - element type | 元素类型
  
  Parameters:
  
  set - the set to filter | 要过滤的集合
  
  predicate - the filter predicate | 过滤谓词
  
  Returns:
  
  filtered immutable set | 过滤后的不可变集合
- isNullOrEmpty
  
  public static boolean isNullOrEmpty(Collection<?> collection)
  
  Check if a collection is null or empty. 检查集合是否为空或为null。
  
  Parameters:
  
  collection - the collection | 集合
  
  Returns:
  
  true if null or empty | 如果为null或为空则返回true
- isNullOrEmpty
  
  public static boolean isNullOrEmpty(Map<?,?> map)
  
  Check if a map is null or empty. 检查映射是否为空或为null。
  
  Parameters:
  
  map - the map | 映射
  
  Returns:
  
  true if null or empty | 如果为null或为空则返回true
- isNullOrEmpty
  
  public static boolean isNullOrEmpty(ImmutableTable<?,?,?> table)
  
  Check if a table is null or empty. 检查表格是否为空或为null。
  
  Parameters:
  
  table - the table | 表格
  
  Returns:
  
  true if null or empty | 如果为null或为空则返回true

Class ImmutableCollectionUtil

Method Summary

Methods inherited from class Object

Method Details

transform

concat

reverse

subList

transform

union

intersection

difference

toMultiset

transform

combine

toBiMap

zipToBiMap

toTable

transpose

toSet

toList

toList

filter

filter

isNullOrEmpty

isNullOrEmpty

isNullOrEmpty