DocumentFile

public abstract class DocumentFile
extends Object

java.lang.Object
   ↳ androidx.documentfile.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 Intent.ACTION_OPEN_DOCUMENT or Intent.ACTION_GET_CONTENT. If you want to let the user pick multiple files, add Intent.EXTRA_ALLOW_MULTIPLE. If you only need the user to save a single file, use Intent.ACTION_CREATE_DOCUMENT. If you use these APIs, you can pass the resulting Intent.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 Intent.ACTION_OPEN_DOCUMENT_TREE to let the user pick a directory. Then pass the resulting Intent.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 ContentResolver.openInputStream(Uri), etc.

To simplify your code on devices running Build.VERSION_CODES.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.