UserDefinedFileAttributeView Basics

UserDefinedFileAttributeView Basics

Some file systems support user-defined attributes (extended attributes), and Java 7 provides a way to read and write this custom metadata.

How it Works

Using UserDefinedFileAttributeView, you can store key-value pairs of metadata directly on the file system, which is separate from the file's content.

Java Example

import java.nio.file.*;
import java.nio.file.attribute.*;
import java.nio.ByteBuffer;
import java.io.IOException;

public class UserAttrExample {
    public static void main(String[] args) throws IOException {
        Path path = Paths.get("test.txt");
        UserDefinedFileAttributeView view = Files.getFileAttributeView(path, UserDefinedFileAttributeView.class);
        if (view != null) {
            System.out.println("User-defined attributes supported.");
        }
    }
}

Output

User-defined attributes supported.

Key Points

• Store custom metadata on files
• Depends on file system support (NTFS, ext4)
• Separate from file content
• Uses ByteBuffers for data