JAVA多态主板示例

public class DuoTaiDemo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		MainBoard mBoard = new MainBoard();
		mBoard.run();
		mBoard.usePCI(null);
		mBoard.usePCI(new NetCard());
		mBoard.usePCI(new SoundCard());
	}
}

interface PCI{
	public void open();
	public void close();
}

class MainBoard{
	public void run() {
		System.out.println("mainboard run");
	}
	public void usePCI(PCI p){
		if(p != null)
		{
			p.open();
			p.close();
		}
	}
}

class NetCard implements PCI{
	public void open() {
		System.out.println("netcard open");
	}
	public void close() {
		System.out.println("netcard close");
	}
}

class SoundCard implements PCI{
	public void open() {
		System.out.println("SoundCard open");
	}
	public void close() {
		System.out.println("SoundCard close");
	}
}