Jimfs is an in-memory file system for Java that fully implements the java.nio.file API introduced in Java 7 and enhanced in Java 8 and beyond. Developed by Google, it allows developers to create and manipulate file systems entirely in memory, making it ideal for testing, simulation, and temporary file operations without touching the actual disk. Jimfs supports most standard file operations, including file and directory creation, deletion, copying, symbolic and hard links, as well as stream-based file reading and writing. It also provides robust support for features like SecureDirectoryStream, WatchService for directory change notifications, and multiple attribute views (basic, posix, unix, dos, and acl). Users can configure Jimfs to mimic UNIX or Windows-style paths and behaviors, depending on the environment they need to simulate.
Features
- Fully in-memory implementation of Java’s java.nio.file API
- Supports creating, moving, copying, and deleting files and directories
- Provides symbolic and hard link functionality
- Supports multiple file attribute views, including POSIX and DOS
- Compatible with WatchService for monitoring directory changes
- Configurable to emulate UNIX or Windows-style file systems