ArrayMap is a generic key->value mapping data structure that is
designed to be more memory efficient than a traditional HashMap,
this implementation is a version of the platform's
android.util.ArrayMap that can be used on older versions of the platform.
Static library support version of the framework's AtomicFile,
a helper class for performing atomic operations on a file by creating a
backup file until a write has successfully completed.
Content and code samples on this page are subject to the licenses described in the Content License. Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
Last updated 2025-02-10 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-02-10 UTC."],[],[],null,["# android.support.v4.util\n\nadded in [version 22.1.0](/topic/libraries/support-library/revisions) \n\nandroid.support.v4.util\n=======================\n\n| This package is part of the Android [support library](/topic/libraries/support-library) which is no longer maintained. The support library has been superseded by [AndroidX](/jetpack/androidx) which is part of [Jetpack](/jetpack). We recommend using the AndroidX libraries in all new projects. You should also consider [migrating](/jetpack/androidx/migrate) existing projects to AndroidX. To find the AndroidX class that maps to this deprecated class, see the AndroidX support library [class\n| mappings](/jetpack/androidx/migrate/class-mappings).\n\nInterfaces\n----------\n\n|------------------------------------------------------------------|-------------------------------------------|\n| [Pools.Pool](/reference/android/support/v4/util/Pools.Pool)\\\u003cT\\\u003e | Interface for managing a pool of objects. |\n\nClasses\n-------\n\n|------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| [ArrayMap](/reference/android/support/v4/util/ArrayMap)\\\u003cK, V\\\u003e | ArrayMap is a generic key-\\\u003evalue mapping data structure that is designed to be more memory efficient than a traditional [HashMap](/reference/java/util/HashMap), this implementation is a version of the platform's `android.util.ArrayMap` that can be used on older versions of the platform. |\n| [ArraySet](/reference/android/support/v4/util/ArraySet)\\\u003cE\\\u003e | ArraySet is a generic set data structure that is designed to be more memory efficient than a traditional [HashSet](/reference/java/util/HashSet). |\n| [AtomicFile](/reference/android/support/v4/util/AtomicFile) | Static library support version of the framework's [AtomicFile](https://developer.android.com/reference/android/util/AtomicFile.html), a helper class for performing atomic operations on a file by creating a backup file until a write has successfully completed. |\n| [CircularArray](/reference/android/support/v4/util/CircularArray)\\\u003cE\\\u003e | CircularArray is a generic circular array data structure that provides O(1) random read, O(1) prepend and O(1) append. |\n| [CircularIntArray](/reference/android/support/v4/util/CircularIntArray) | CircularIntArray is a circular integer array data structure that provides O(1) random read, O(1) prepend and O(1) append. |\n| [LongSparseArray](/reference/android/support/v4/util/LongSparseArray)\\\u003cE\\\u003e | SparseArray mapping longs to Objects, a version of the platform's `android.util.LongSparseArray` that can be used on older versions of the platform. |\n| [LruCache](/reference/android/support/v4/util/LruCache)\\\u003cK, V\\\u003e | Static library version of `android.util.LruCache`. |\n| [ObjectsCompat](/reference/android/support/v4/util/ObjectsCompat) | This class consists of static utility methods for operating on objects. |\n| [Pair](/reference/android/support/v4/util/Pair)\\\u003cF, S\\\u003e | Container to ease passing around a tuple of two objects. |\n| [PatternsCompat](/reference/android/support/v4/util/PatternsCompat) | Commonly used regular expression patterns. |\n| [Pools](/reference/android/support/v4/util/Pools) | Helper class for creating pools of objects. |\n| [Pools.SimplePool](/reference/android/support/v4/util/Pools.SimplePool)\\\u003cT\\\u003e | Simple (non-synchronized) pool of objects. |\n| [Pools.SynchronizedPool](/reference/android/support/v4/util/Pools.SynchronizedPool)\\\u003cT\\\u003e | Synchronized) pool of objects. |\n| [SimpleArrayMap](/reference/android/support/v4/util/SimpleArrayMap)\\\u003cK, V\\\u003e | Base implementation of [ArrayMap](/reference/android/support/v4/util/ArrayMap) that doesn't include any standard Java container API interoperability. |\n| [SparseArrayCompat](/reference/android/support/v4/util/SparseArrayCompat)\\\u003cE\\\u003e | SparseArrays map integers to Objects. |\n\n-\n\n Interfaces\n ----------\n\n - [Pools.Pool](/reference/android/support/v4/util/Pools.Pool)\n-\n\n Classes\n -------\n\n - [ArrayMap](/reference/android/support/v4/util/ArrayMap)\n - [ArraySet](/reference/android/support/v4/util/ArraySet)\n - [AtomicFile](/reference/android/support/v4/util/AtomicFile)\n - [CircularArray](/reference/android/support/v4/util/CircularArray)\n - [CircularIntArray](/reference/android/support/v4/util/CircularIntArray)\n - [LongSparseArray](/reference/android/support/v4/util/LongSparseArray)\n - [LruCache](/reference/android/support/v4/util/LruCache)\n - [ObjectsCompat](/reference/android/support/v4/util/ObjectsCompat)\n - [Pair](/reference/android/support/v4/util/Pair)\n - [PatternsCompat](/reference/android/support/v4/util/PatternsCompat)\n - [Pools](/reference/android/support/v4/util/Pools)\n - [Pools.SimplePool](/reference/android/support/v4/util/Pools.SimplePool)\n - [Pools.SynchronizedPool](/reference/android/support/v4/util/Pools.SynchronizedPool)\n - [SimpleArrayMap](/reference/android/support/v4/util/SimpleArrayMap)\n - [SparseArrayCompat](/reference/android/support/v4/util/SparseArrayCompat)"]]