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Summary: Methods | Inherited Methods | [Expand All]

DocumentFile

public abstract class DocumentFile
extends Object

java.lang.Object
↳	android.support.v4.provider.DocumentFile

Representation of a document backed by either a DocumentsProvider or a raw file on disk. This is a utility class designed to emulate the traditional File interface. It offers a simplified view of a tree of documents, but it has substantial overhead. For optimal performance and a richer feature set, use the DocumentsContract methods and constants directly.

There are several differences between documents and traditional files:

Documents express their display name and MIME type as separate fields, instead of relying on file extensions. Some documents providers may still choose to append extensions to their display names, but that's an implementation detail.
A single document may appear as the child of multiple directories, so it doesn't inherently know who its parent is. That is, documents don't have a strong notion of path. You can easily traverse a tree of documents from parent to child, but not from child to parent.
Each document has a unique identifier within that provider. This identifier is an opaque implementation detail of the provider, and as such it must not be parsed.

Before using this class, first consider if you really need access to an entire subtree of documents. The principle of least privilege dictates that you should only ask for access to documents you really need. If you only need the user to pick a single file, use ACTION_OPEN_DOCUMENT or ACTION_GET_CONTENT. If you want to let the user pick multiple files, add EXTRA_ALLOW_MULTIPLE. If you only need the user to save a single file, use ACTION_CREATE_DOCUMENT. If you use these APIs, you can pass the resulting getData() into fromSingleUri(Context, Uri) to work with that document.

If you really do need full access to an entire subtree of documents, start by launching ACTION_OPEN_DOCUMENT_TREE to let the user pick a directory. Then pass the resulting getData() into fromTreeUri(Context, Uri) to start working with the user selected tree.

As you navigate the tree of DocumentFile instances, you can always use getUri() to obtain the Uri representing the underlying document for that object, for use with openInputStream(Uri), etc.

To simplify your code on devices running KITKAT or earlier, you can use fromFile(File) which emulates the behavior of a DocumentsProvider.

See also:

Summary

Public methods
`abstract boolean`	`canRead()` Indicates whether the current context is allowed to read from this file.
`abstract boolean`	`canWrite()` Indicates whether the current context is allowed to write to this file.
`abstract DocumentFile`	`createDirectory(String displayName)` Create a new directory as a direct child of this directory.
`abstract DocumentFile`	`createFile(String mimeType, String displayName)` Create a new document as a direct child of this directory.
`abstract boolean`	`delete()` Deletes this file.
`abstract boolean`	`exists()` Returns a boolean indicating whether this file can be found.
`DocumentFile`	`findFile(String displayName)` Search through `listFiles()` for the first document matching the given display name.
`static DocumentFile`	`fromFile(File file)` Create a `DocumentFile` representing the filesystem tree rooted at the given `File`.
`static DocumentFile`	`fromSingleUri(Context context, Uri singleUri)` Create a `DocumentFile` representing the single document at the given `Uri`.
`static DocumentFile`	`fromTreeUri(Context context, Uri treeUri)` Create a `DocumentFile` representing the document tree rooted at the given `Uri`.
`abstract String`	`getName()` Return the display name of this document.
`DocumentFile`	`getParentFile()` Return the parent file of this document.
`abstract String`	`getType()` Return the MIME type of this document.
`abstract Uri`	`getUri()` Return a Uri for the underlying document represented by this file.
`abstract boolean`	`isDirectory()` Indicates if this file represents a directory.
`static boolean`	`isDocumentUri(Context context, Uri uri)` Test if given Uri is backed by a `DocumentsProvider`.
`abstract boolean`	`isFile()` Indicates if this file represents a file.
`abstract long`	`lastModified()` Returns the time when this file was last modified, measured in milliseconds since January 1st, 1970, midnight.
`abstract long`	`length()` Returns the length of this file in bytes.
`abstract DocumentFile[]`	`listFiles()` Returns an array of files contained in the directory represented by this file.
`abstract boolean`	`renameTo(String displayName)` Renames this file to `displayName`.

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 millis, 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 millis)` 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.

Public methods

canRead

boolean canRead ()

Indicates whether the current context is allowed to read from this file.

Returns
`boolean`	`true` if this file can be read, `false` otherwise.

canWrite

boolean canWrite ()

Indicates whether the current context is allowed to write to this file.

Returns
`boolean`	`true` if this file can be written, `false` otherwise.

See also:

createDirectory

DocumentFile createDirectory (String displayName)

Create a new directory as a direct child of this directory.

Parameters
`displayName`	`String`: name of new directory

Returns
`DocumentFile`	file representing newly created directory, or null if failed

Throws
`UnsupportedOperationException`	when working with a single document created from `fromSingleUri(Context, Uri)`.

See also:

createDocument(ContentResolver, Uri, String, String)

createFile

DocumentFile createFile (String mimeType, 
                String displayName)

Create a new document as a direct child of this directory.

Parameters
`mimeType`	`String`: MIME type of new document, such as `image/png` or `audio/flac`
`displayName`	`String`: name of new document, without any file extension appended; the underlying provider may choose to append the extension

Returns
`DocumentFile`	file representing newly created document, or null if failed

Throws
`UnsupportedOperationException`	when working with a single document created from `fromSingleUri(Context, Uri)`.

See also:

createDocument(ContentResolver, Uri, String, String)

delete

boolean delete ()

Deletes this file.

Note that this method does not throw IOException on failure. Callers must check the return value.

Returns
`boolean`	`true` if this file was deleted, `false` otherwise.

See also:

deleteDocument(ContentResolver, Uri)

exists

boolean exists ()

Returns a boolean indicating whether this file can be found.

Returns
`boolean`	`true` if this file exists, `false` otherwise.

findFile

DocumentFile findFile (String displayName)

Search through listFiles() for the first document matching the given display name. Returns null when no matching document is found.

Parameters
`displayName`	`String`

Returns
`DocumentFile`

Throws
`UnsupportedOperationException`	when working with a single document created from `fromSingleUri(Context, Uri)`.

fromFile

DocumentFile fromFile (File file)

Create a DocumentFile representing the filesystem tree rooted at the given File. This doesn't give you any additional access to the underlying files beyond what your app already has.

getUri() will return file:// Uris for files explored through this tree.

Parameters
`file`	`File`

Returns
`DocumentFile`

fromSingleUri

DocumentFile fromSingleUri (Context context, 
                Uri singleUri)

Create a DocumentFile representing the single document at the given Uri. This is only useful on devices running KITKAT or later, and will return null when called on earlier platform versions.

Parameters
`context`	`Context`
`singleUri`	`Uri`: the `getData()` from a successful `ACTION_OPEN_DOCUMENT` or `ACTION_CREATE_DOCUMENT` request.

Returns
`DocumentFile`

fromTreeUri

DocumentFile fromTreeUri (Context context, 
                Uri treeUri)

Create a DocumentFile representing the document tree rooted at the given Uri. This is only useful on devices running LOLLIPOP or later, and will return null when called on earlier platform versions.

Parameters
`context`	`Context`
`treeUri`	`Uri`: the `getData()` from a successful `ACTION_OPEN_DOCUMENT_TREE` request.

Returns
`DocumentFile`

getName

String getName ()

Return the display name of this document.

Returns
`String`

See also:

COLUMN_DISPLAY_NAME

getParentFile

DocumentFile getParentFile ()

Return the parent file of this document. Only defined inside of the user-selected tree; you can never escape above the top of the tree.

The underlying DocumentsProvider only defines a forward mapping from parent to child, so the reverse mapping of child to parent offered here is purely a convenience method, and it may be incorrect if the underlying tree structure changes.

Returns
`DocumentFile`

getType

String getType ()

Return the MIME type of this document.

Returns
`String`

See also:

COLUMN_MIME_TYPE

getUri

Uri getUri ()

Return a Uri for the underlying document represented by this file. This can be used with other platform APIs to manipulate or share the underlying content. You can use isDocumentUri(Context, Uri) to test if the returned Uri is backed by a DocumentsProvider.

Returns
`Uri`

See also:

isDirectory

boolean isDirectory ()

Indicates if this file represents a directory.

Returns
`boolean`	`true` if this file is a directory, `false` otherwise.

See also:

MIME_TYPE_DIR

isDocumentUri

boolean isDocumentUri (Context context, 
                Uri uri)

Test if given Uri is backed by a DocumentsProvider.

Parameters
`context`	`Context`
`uri`	`Uri`

Returns
`boolean`

isFile

boolean isFile ()

Indicates if this file represents a file.

Returns
`boolean`	`true` if this file is a file, `false` otherwise.

See also:

COLUMN_MIME_TYPE

lastModified

long lastModified ()

Returns the time when this file was last modified, measured in milliseconds since January 1st, 1970, midnight. Returns 0 if the file does not exist, or if the modified time is unknown.

Returns
`long`	the time when this file was last modified.

See also:

COLUMN_LAST_MODIFIED

length

long length ()

Returns the length of this file in bytes. Returns 0 if the file does not exist, or if the length is unknown. The result for a directory is not defined.

Returns
`long`	the number of bytes in this file.

See also:

COLUMN_SIZE

listFiles

DocumentFile[] listFiles ()

Returns an array of files contained in the directory represented by this file.

Returns
`DocumentFile[]`	an array of files or `null`.

Throws
`UnsupportedOperationException`	when working with a single document created from `fromSingleUri(Context, Uri)`.

See also:

buildChildDocumentsUriUsingTree(Uri, String)

renameTo

boolean renameTo (String displayName)

Renames this file to displayName.

Note that this method does not throw IOException on failure. Callers must check the return value.

Some providers may need to create a new document to reflect the rename, potentially with a different MIME type, so getUri() and getType() may change to reflect the rename.

When renaming a directory, children previously enumerated through listFiles() may no longer be valid.

Parameters
`displayName`	`String`: the new display name.

Returns
`boolean`	true on success.

Throws
`UnsupportedOperationException`	when working with a single document created from `fromSingleUri(Context, Uri)`.

See also:

renameDocument(ContentResolver, Uri, String)