Hello World using design patterns

DesignPatterns.java

// https://developers.slashdot.org/comments.pl?sid=33602&cid=3636102
public interface MessageStrategy {
	public void sendMessage();
}

public abstract class AbstractStrategyFactory {
	public abstract MessageStrategy createStrategy(MessageBody mb);
}

public class MessageBody {
	Object payload;
	public Object getPayload() {
		return payload;
	}
	public void configure(Object obj) {
		payload = obj;
	}
	public void send(MessageStrategy ms) {
		ms.sendMessage();
	}
}

public class DefaultFactory extends AbstractStrategyFactory {
	private DefaultFactory() {;}
	static DefaultFactory instance;
	public static AbstractStrategyFactory getInstance() {
		if (instance==null) instance = new DefaultFactory();
		return instance;
	}

	public MessageStrategy createStrategy(final MessageBody mb) {
		return new MessageStrategy() {
			MessageBody body = mb;
			public void sendMessage() {
				Object obj = body.getPayload();
				System.out.println((String)obj);
			}
		};
	}
}

public class HelloWorld {
	public static void main(String[] args) {
		MessageBody mb = new MessageBody();
		mb.configure("Hello World!");
		AbstractStrategyFactory asf = DefaultFactory.getInstance();
		MessageStrategy strategy = asf.createStrategy(mb);
		mb.send(strategy);
	}
}