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

import java.io.IOException;
import org.apache.commons.io.input.NullReader;

class Example {
    public static void main(String[] args) {
        try (NullReader nr = new NullReader()) {
            char[] buffer = new char[1024];
            int charsRead = nr.read(buffer);
            System.out.println("Chars read: " + charsRead); // -1
        } catch (IOException e) {
            // handle exception
        }
    }
}

This code creates a NullReader which is a reader that discards any characters read from it and always returns -1 when read.

In this example, it read from the NullReader using the read method, it returns -1, since it's an empty reader.

It can be used to test code that requires a Reader, or when you want to discard data from a Reader but don't want to modify the original code.

It is equivalent to the NullInputStream, but for character data.