added in version 22.1.0
belongs to Maven artifact com.android.support:documentfile:28.0.0-alpha1
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.

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 boolean isVirtual()

Indicates if this file represents a virtual document.

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

Public methods

canRead

added in version 22.1.0
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

added in version 22.1.0
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.

createDirectory

added in version 22.1.0
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).

createFile

added in version 22.1.0
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).

delete

added in version 22.1.0
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.

exists

added in version 22.1.0
boolean exists ()

Returns a boolean indicating whether this file can be found.

Returns
boolean true if this file exists, false otherwise.

findFile

added in version 22.1.0
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

added in version 22.1.0
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

added in version 22.1.0
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

added in version 22.1.0
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

added in version 22.1.0
String getName ()

Return the display name of this document.

Returns
String

getParentFile

added in version 22.1.0
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

added in version 22.1.0
String getType ()

Return the MIME type of this document.

Returns
String

See also:

getUri

added in version 22.1.0
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: