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StorageVolume

public final class StorageVolume
extends Object implements Parcelable

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

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 Acess 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 is deprecated. 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 `DocumentsProvider`s 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`.
`String`	`getState()` Returns the current state of the volume.
`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 timeout, int nanos)` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
`final void`	`wait(long timeout)` Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
`final void`	`wait()` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

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

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

public static final Creator<StorageVolume> CREATOR

Public methods

createAccessIntent

public Intent createAccessIntent (String directoryName)

This method is deprecated.
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(String), 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

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.

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

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

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

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.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Parameters
`obj`	`Object`: the reference object with which to compare.

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

getDescription

public String getDescription (Context context)

Returns a user-visible description of the volume.

Parameters
`context`	`Context`

Returns
`String`	the volume description

getDirectory

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

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:

getState

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`.

getUuid

public String getUuid ()

Gets the volume UUID, if any.

Returns
`String`	This value may be `null`.

hashCode

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(Object) 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(java.lang.Object) 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.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

Returns
`int`	a hash code value for this object.

isEmulated

public boolean isEmulated ()

Returns true if the volume is emulated.

Returns
`boolean`	is removable

isPrimary

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

public boolean isRemovable ()

Returns true if the volume is removable.

Returns
`boolean`	is removable

toString

public String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())

Returns
`String`	a string representation of the object.

writeToParcel

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.
`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