Folder descriptor

What is a FolderDescriptor?

FileManagerModule supports folders for organizing file resources. A single folder can contain file resources or other folder resources.

A FolderDescriptor is the URI of a single folder resource in the system.

Just like FileDescriptor it can be represented as a string, for example:


A FolderDescriptor is made up of two segments:

Repository id

The unique id of the FileRepository where this file is located (my-repository). A repository id is always required.

Folder id

The id of the folder in the repository.

Most characters are allowed in descriptor segments, with the following exceptions:

  • colon (:) is not allowed

  • backward slash (\) will always be replaced by forward slash (/)

In the string representation the different segments are separated with a colon.

FolderDescriptor examples

URI Repository id Folder id






A folder descriptor URI should always end with a training forward slash (/).

Parsing a string URI to a FolderDescriptor can be done with FolderDescriptor.of().

FolderDescriptor.of( "my-repository:folder/" )

Calling FolderDescriptor.toString() will give you the normalized string representation.

The Spring ConversionService can automatically convert a String to a FolderDescriptor, making it easy to use in data binding scenarios.

Root folder

Every FileRepository has a virtual root folder, in which the file resources without a specific folder id will be located. The folder id of a root folder is always /.


A descriptor for a root folder can be created using FolderDescriptor.rootFolder( "repository-id" ).

Retrieving a FolderDescriptor

A FolderDescriptor is always part of a FileDescriptor and can be retrieved with FileDescriptor.getFolderDescriptor().

Whereas FileDescriptor.getFolderId() might return a null value for the root folder, a FolderDescriptor will never be null.

Parent folder descriptor

The descriptor contains the entire folder hierarchy as path segments separated with a forward slash (/).

The descriptor of the parent folder can be retrieved using FolderDescriptor.getParentFolderDescriptor(). The latter returns an Optional<FolderDescriptor> which will be empty if the current descriptor represents the root folder of the repository.