Plume File is a modular Java library that provides several modules to easily handle files in a project from storage to download. Its goal is to provide great performance with a great Java API: it can handle files of several gigabytes with a JVM that has an Xmx of only 128Mo.

Plume File that has some small dependencies on the Plume Framework, especially to the conf and scheduler modules.

Looking for a demo? Check out the file service implementation on the Plume Demo project.

Plume file library follows a modular architecture to make it easy to change the storage engine or the API technology.

Some necessary file storage choices has been taken for this library:

• The storage of the files binary data is separated from the storage of files metadata
• Files are uniquely identified by an UUID where the file extension is appended. So for example, the file cat.jpg might be stored in the file storage as the file 35a0da5e-1036-43ae-ae04-8c4076f5a9b3.jpg. The metadata will then enable to retrieve the original name.

To categorize file, each file is associated with a FileType. This consists of a user defined enum with values like LANDSCAPES or PROFILE_PICTURE. This category is especially used by the plume-file-metadata-database to provide a convenient way to delete files.

The main composant is the module plume-file-core which exposes file storage interfaces, FileMetadataService and FileStorageService that must be implemented. So to use the main entry point FileService:

• The module plume-file-core must be installed
• One of the metadata modules must be installed
• One of the file storage modules must be installed

Jersey connectors are provided to upload/expose files through API.

Some modules implement the FileUrlService to be able to retrieve the full URL of a file stored using Plume File. That is the case of:

• plume-file-web-download-jersey
• In the future, the AWS S3 file storage module

These are modules to be used with the main plume-file-core module.

The storage modules implements FileStorageService:

• plume-file-storage-database: store uploaded file in a database
• plume-file-storage-system: store uploaded file on a system disk

The metadata module implements FileMetadataService:

• plume-file-metadata-database: store file metadata in a database

Those modules provide API connectors to serve and upload files.

• plume-file-web-download-jersey: serve stored file through a Jersey based single web-service
• plume-file-web-upload: upload file using HTTP multipart

plume-file-core

# The time of day at which the cleaning task is scheduled
file.cleaning-hour = "03:00"
# The algorithm used for checksum file calculation
file.checksum-algorithm = "SHA-256"

plume-file-storage-system

# The directory in which the files are stored locally
file.storage.local-path = "plume-file-data/"

plume-file-web-download-jersey

# The Cache-Control response header value for max-age, it represents the time files will be stored in cache on browsers
file.cache.http.max-age = "365 days"
# Internal server file content configuration: the duration after which a file will be removed from the cache
file.cache.data.expires-after-access-duration = "1 day"
# Internal server file content configuration: the maximum size of the cache
file.cache.data.max-cache-size = "64 MB"
# Internal server file metadata configuration: the duration after which metadata will be removed from the cache
file.cache.metadata.expires-after-access-duration = "1 day"
# Internal server file metadata configuration: the maximum number of metadata elements stored in the cache
file.cache.metadata.max-elements = 10000
# The base file URL used by FileUrlService.url(). If the config value application.base-url is defined, this can be replaced by file.url.base-path = ${application.base-url}"/api/files"
file.url.base-path = "/api/files"

All migration guides are available in the Plume File Github releases.