AsyncPrinter.java

import java.util.*;

public class AsyncPrinter extends Thread
{
	private Queue<String> queue;
	
	public AsyncPrinter()
	{
		this.queue=new LinkedList<>();
		this.setDaemon(true);
		this.start();
	}
	
	public void run()
	{
		String name;
		while(true)
		{
			while((name=this.queue.poll())!=null)
			{
				System.out.print("Hello, ");
				System.out.println(name);
			}
			try
			{
				this.wait();
			}
			catch(Exception ex)
			{
			}
		}
	}
	
	public boolean add(String name)
	{
		boolean ret=queue.offer(name);
		try
		{
			this.notifyAll();
		}
		catch(IllegalMonitorStateException ex)
		{
		}
		return ret;
	}
	
	public static void main(String... args)
	{
		AsyncPrinter printer=new AsyncPrinter();
		printer.add("Alan");
	}
}

For the demo, how about this.setDaemon(false); ?