music.java.bak

来自「java编程思想的部分实现」· BAK 代码 · 共 37 行

//:c07:music:Music.java
class Note 
{
	private int value;
	private Note(int val)
	{
		value=val;
	}
	public static final Note MIDDLE_C=new Note(0),C_SHARP=new Note(1),B_FLAT=new Note(2);
}

class Instrument
{
	public void play(Note n)
	{
		System.out.println("Instrument.play()");
	}
}
class Wind extends Instrument
{
	public void play(Note n)
	{
		System.out.println("Wind.play()");
	}
}
public class Music
{
	public static void tune(Instrument i)
	{
		i.play(Note.MIDDLE_C);
	}
	pblic static void main(String []args)
	{
		Wind flute=new Wind();
		tune(flute);
	}
}