Here is an example of how to use the ContentReference class from the Apache Commons IO library:

import org.apache.commons.io.input.ContentReference;

public class Example {
    public static void main(String[] args) {
        // Create a ContentReference
        ContentReference reference = new ContentReference("http://example.com/file.txt");

        // Get the URL of the ContentReference
        String url = reference.getUrl();

        // Print the URL
        System.out.println("URL: " + url);

        // Get the filename of the ContentReference
        String filename = reference.getFileName();

        // Print the filename
        System.out.println("Filename: " + filename);
    }
}

In this example, the ContentReference class is being used to create a reference to a file located at "http://example.com/file.txt". The getUrl() method is used to get the URL of the ContentReference and the getFileName() method is used to get the filename of the ContentReference. The URL and the filename are then printed.

The ContentReference class is useful in cases where you want to reference a remote file, and you want to extract the URL and the filename of the file. This can be useful for example when you want to download a file and you want to give it the same name as it has in the remote server or you want to make a reference to a file that is not stored in the local filesystem.