Added in API level 24

Summary: Constants | Inherited Constants | Fields | Methods | Inherited Methods

StorageVolume

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Kotlin |Java

public final class StorageVolume
extends Object implements Parcelable

java.lang.Object
↳	android.os.storage.StorageVolume

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Information about a shared/external storage volume for a specific user.

A device always has one (and one only) primary storage volume, but it could have extra volumes, like SD cards and USB drives. This object represents the logical view of a storage volume for a specific user: different users might have different views for the same physical volume (for example, if the volume is a built-in emulated storage).

The storage volume is not necessarily mounted, applications should use getState() to verify its state.

Applications willing to read or write to this storage volume needs to get a permission from the user first, which can be achieved in the following ways:

• To get access to standard directories (like the Environment#DIRECTORY_PICTURES), they can use the createAccessIntent(java.lang.String). This is the recommend way, since it provides a simpler API and narrows the access to the given directory (and its descendants).
• To get access to any directory (and its descendants), they can use the Storage Access Framework APIs (such as Intent#ACTION_OPEN_DOCUMENT and Intent#ACTION_OPEN_DOCUMENT_TREE, although these APIs do not guarantee the user will select this specific volume.
• To get read and write access to the primary storage volume, applications can declare the Manifest.permission.READ_EXTERNAL_STORAGE and Manifest.permission.WRITE_EXTERNAL_STORAGE permissions respectively, with the latter including the former. This approach is discouraged, since users may be hesitant to grant broad access to all files contained on a storage device.

It can be obtained through StorageManager#getStorageVolumes() and StorageManager#getPrimaryStorageVolume() and also as an extra in some broadcasts (see EXTRA_STORAGE_VOLUME).

See Environment#getExternalStorageDirectory() for more info about shared/external storage semantics.

Summary

Constants
String	EXTRA_STORAGE_VOLUME Name of the Parcelable extra in the Intent#ACTION_MEDIA_REMOVED, Intent#ACTION_MEDIA_UNMOUNTED, Intent#ACTION_MEDIA_CHECKING, Intent#ACTION_MEDIA_NOFS, Intent#ACTION_MEDIA_MOUNTED, Intent#ACTION_MEDIA_SHARED, Intent#ACTION_MEDIA_BAD_REMOVAL, Intent#ACTION_MEDIA_UNMOUNTABLE, and Intent#ACTION_MEDIA_EJECT broadcast that contains a StorageVolume.

Inherited constants

From interface android.os.Parcelable int CONTENTS_FILE_DESCRIPTOR Descriptor bit used with describeContents(): indicates that the Parcelable object's flattened representation includes a file descriptor. int PARCELABLE_WRITE_RETURN_VALUE Flag for use with writeToParcel(Parcel, int): the object being written is a return value, that is the result of a function such as "Parcelable someFunction()", "void someFunction(out Parcelable)", or "void someFunction(inout Parcelable)".

Fields
public static final Creator<StorageVolume>	CREATOR

Public methods
Intent	createAccessIntent(String directoryName) This method was deprecated in API level 29. Callers should migrate to using Intent#ACTION_OPEN_DOCUMENT_TREE instead. Launching this Intent on devices running Build.VERSION_CODES.Q or higher, will immediately finish with a result code of Activity.RESULT_CANCELED.
Intent	createOpenDocumentTreeIntent() Builds an Intent#ACTION_OPEN_DOCUMENT_TREE to allow the user to grant access to any directory subtree (or entire volume) from the DocumentsProviders available on the device.
int	describeContents() Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.
boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
String	getDescription(Context context) Returns a user-visible description of the volume.
File	getDirectory() Returns the directory where this volume is currently mounted.
String	getMediaStoreVolumeName() Return the volume name that can be used to interact with this storage device through MediaStore.
UserHandle	getOwner() Returns the user that owns this volume
String	getState() Returns the current state of the volume.
UUID	getStorageUuid() Gets the converted volume UUID.
String	getUuid() Gets the volume UUID, if any.
int	hashCode() Returns a hash code value for the object.
boolean	isEmulated() Returns true if the volume is emulated.
boolean	isPrimary() Returns true if the volume is the primary shared/external storage, which is the volume backed by Environment#getExternalStorageDirectory().
boolean	isRemovable() Returns true if the volume is removable.
String	toString() Returns a string representation of the object.
void	writeToParcel(Parcel parcel, int flags) Flatten this object in to a Parcel.

Inherited methods
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
From interface android.os.Parcelable abstract int describeContents() Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. abstract void writeToParcel(Parcel dest, int flags) Flatten this object in to a Parcel.

Constants

EXTRA_STORAGE_VOLUME

Added in API level 24

public static final String EXTRA_STORAGE_VOLUME

Name of the Parcelable extra in the Intent#ACTION_MEDIA_REMOVED, Intent#ACTION_MEDIA_UNMOUNTED, Intent#ACTION_MEDIA_CHECKING, Intent#ACTION_MEDIA_NOFS, Intent#ACTION_MEDIA_MOUNTED, Intent#ACTION_MEDIA_SHARED, Intent#ACTION_MEDIA_BAD_REMOVAL, Intent#ACTION_MEDIA_UNMOUNTABLE, and Intent#ACTION_MEDIA_EJECT broadcast that contains a StorageVolume.

Constant Value: "android.os.storage.extra.STORAGE_VOLUME"

Fields

CREATOR

Added in API level 24

public static final Creator<StorageVolume> CREATOR

Public methods

createAccessIntent

Added in API level 24
Deprecated in API level 29

public Intent createAccessIntent (String directoryName)

This method was deprecated in API level 29.
Callers should migrate to using Intent#ACTION_OPEN_DOCUMENT_TREE instead. Launching this Intent on devices running Build.VERSION_CODES.Q or higher, will immediately finish with a result code of Activity.RESULT_CANCELED.

Builds an intent to give access to a standard storage directory or entire volume after obtaining the user's approval.

When invoked, the system will ask the user to grant access to the requested directory (and its descendants). The result of the request will be returned to the activity through the onActivityResult method.

To gain access to descendants (child, grandchild, etc) documents, use DocumentsContract#buildDocumentUriUsingTree(Uri, String), or DocumentsContract#buildChildDocumentsUriUsingTree(Uri, String) with the returned URI.

If your application only needs to store internal data, consider using Context.getExternalFilesDirs, Context#getExternalCacheDirs(), or Context#getExternalMediaDirs(), which require no permissions to read or write.

Access to the entire volume is only available for non-primary volumes (for the primary volume, apps can use the Manifest.permission.READ_EXTERNAL_STORAGE and Manifest.permission.WRITE_EXTERNAL_STORAGE permissions) and should be used with caution, since users are more likely to deny access when asked for entire volume access rather than specific directories.

Parameters
directoryName	String: must be one of Environment#DIRECTORY_MUSIC, Environment#DIRECTORY_PODCASTS, Environment#DIRECTORY_RINGTONES, Environment#DIRECTORY_ALARMS, Environment#DIRECTORY_NOTIFICATIONS, Environment#DIRECTORY_PICTURES, Environment#DIRECTORY_MOVIES, Environment#DIRECTORY_DOWNLOADS, Environment#DIRECTORY_DCIM, or Environment#DIRECTORY_DOCUMENTS, or null to request access to the entire volume.

Returns
Intent	intent to request access, or null if the requested directory is invalid for that volume.

See also:

• DocumentsContract

createOpenDocumentTreeIntent

Added in API level 29

public Intent createOpenDocumentTreeIntent ()

Builds an Intent#ACTION_OPEN_DOCUMENT_TREE to allow the user to grant access to any directory subtree (or entire volume) from the DocumentsProviders available on the device. The initial location of the document navigation will be the root of this StorageVolume. Note that the returned Intent simply suggests that the user picks this StorageVolume by default, but the user may select a different location. Callers must respect the user's chosen location, even if it is different from the originally requested location.

Returns
Intent	intent to Intent#ACTION_OPEN_DOCUMENT_TREE initially showing the contents of this StorageVolume This value cannot be null.

See also:

• Intent.ACTION_OPEN_DOCUMENT_TREE

describeContents

Added in API level 24

public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Returns
int	a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or CONTENTS_FILE_DESCRIPTOR

equals

Added in API level 24

public boolean equals (Object obj)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
obj	Object: This value may be null.

Returns
boolean	true if this object is the same as the obj argument; false otherwise.

getDescription

Added in API level 24

public String getDescription (Context context)

Returns a user-visible description of the volume.

Parameters
context	Context

Returns
String	the volume description

getDirectory

Added in API level 30

public File getDirectory ()

Returns the directory where this volume is currently mounted.

Direct filesystem access via this path has significant emulation overhead, and apps are instead strongly encouraged to interact with media on storage volumes via the MediaStore APIs.

This directory does not give apps any additional access beyond what they already have via MediaStore.

Returns
File	directory where this volume is mounted, or null if the volume is not currently mounted.

getMediaStoreVolumeName

Added in API level 30

public String getMediaStoreVolumeName ()

Return the volume name that can be used to interact with this storage device through MediaStore.

Returns
String	opaque volume name, or null if this volume is not indexed by MediaStore.

See also:

• MediaStore.Audio.Media.getContentUri(String)
• MediaStore.Video.Media.getContentUri(String)
• MediaStore.Images.Media.getContentUri(String)

getOwner

Added in API level 33

public UserHandle getOwner ()

Returns the user that owns this volume

Returns
UserHandle	This value cannot be null.

getState

Added in API level 24

public String getState ()

Returns the current state of the volume.

Returns
String	one of Environment#MEDIA_UNKNOWN, Environment#MEDIA_REMOVED, Environment#MEDIA_UNMOUNTED, Environment#MEDIA_CHECKING, Environment#MEDIA_NOFS, Environment#MEDIA_MOUNTED, Environment#MEDIA_MOUNTED_READ_ONLY, Environment#MEDIA_SHARED, Environment#MEDIA_BAD_REMOVAL, or Environment#MEDIA_UNMOUNTABLE.

getStorageUuid

Added in API level 31

public UUID getStorageUuid ()

Gets the converted volume UUID. If a valid UUID is returned, it is compatible with other APIs that make use of UUID like StorageManager#allocateBytes and ApplicationInfo.storageUuid

Returns
UUID	the UUID for the volume or null for "portable" storage devices which haven't been adopted.

See also:

• Adoptable storage

getUuid

Added in API level 24

public String getUuid ()

Gets the volume UUID, if any.

Returns
String	This value may be null.

hashCode

Added in API level 24

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns
int	a hash code value for this object.

isEmulated

Added in API level 24

public boolean isEmulated ()

Returns true if the volume is emulated.

Returns
boolean	is emulated

isPrimary

Added in API level 24

public boolean isPrimary ()

Returns true if the volume is the primary shared/external storage, which is the volume backed by Environment#getExternalStorageDirectory().

Returns
boolean

isRemovable

Added in API level 24

public boolean isRemovable ()

Returns true if the volume is removable.

Returns
boolean	is removable

toString

Added in API level 24

public String toString ()

Returns a string representation of the object.

Returns
String	a string representation of the object.

writeToParcel

Added in API level 24

public void writeToParcel (Parcel parcel, 
                int flags)

Flatten this object in to a Parcel.

Parameters
parcel	Parcel: The Parcel in which the object should be written. This value cannot be null.
flags	int: Additional flags about how the object should be written. May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES