依赖倒置原则示例

package packagedemo;

public class 键盘  implements Reader{

	@Override
	public int read() {
		System.out.println("从键盘读取：");
		//return  Keyboard.Read();
		return 0;
	}

}

　　

package packagedemo;

public class 其他读设备 implements Reader {

    @Override
    public int read() {
        System.out.println("其他设备读取");
        return 0;
    }
    

}

package packagedemo;

public interface Writer {

	void write();
}

　　

package packagedemo;

public class 其他写设备 implements Writer {

    @Override
    public void write() {
        // Printer.write();
        System.out.println("其他设备写");
        
        
    }
    

}

【Copy类】

package packagedemo;

public class Copy {

	private Reader r;//接口
	private Writer w;//接口
	
	public Copy(Reader r,Writer w)
	{
		this.r = r;
		this.w = w;
		
	}
	
	void read()//du
	{
		r.read();
	}
	
	void write()//xie
	{
		w.write();
	}
}

　　

 

【测试类】

 

package packagedemo;

public class Test {

    public static void main(String []args)//main（）函数
    {
        Copy c = new Copy(new 其他读设备(), new 显示器());
        
        c.write();
        
        c.read();
    }
}