Here is an example of using the QueueOutputStream class from the org.apache.commons.io package in Java to write data to a queue of OutputStreams:

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

import org.apache.commons.io.output.QueueOutputStream;

public class QueueOutputStreamExample {
    public static void main(String[] args) throws IOException {
        // Create a BlockingQueue
        BlockingQueue<ByteArrayOutputStream> queue = new LinkedBlockingQueue<>();
        // Create a QueueOutputStream
        QueueOutputStream qos = new QueueOutputStream(queue);

        // Write to the QueueOutputStream
        qos.write("Hello World!".getBytes());
        // Close the QueueOutputStream
        qos.close();

        // Get the written data from the queue
        ByteArrayOutputStream baos = queue.take();
        System.out.println(new String(baos.toByteArray())); // "Hello World!"
    }
}

In this example, a BlockingQueue of ByteArrayOutputStreams is created and a QueueOutputStream is created to write to the queue. The QueueOutputStream is then used to write the string "Hello World!" to the queue, and the written data is taken from the queue and printed.

This class is useful when you need to write data to multiple OutputStreams in a concurrent environment. The QueueOutputStream class allows you to write data to a queue of OutputStreams, and the data can be consumed by multiple threads.

It can be used in situations where you want to write data to a queue for later processing, or when you want to write data to multiple OutputStreams in a concurrent environment.