cylinder.java

（1） 编写一个代表圆柱体的Cylinder类

import p3.circle;
import p2.Point;
public class Cylinder extends p3.circle
{
	int height;
	Cylinder(){}
	Cylinder(Point p,int r,int h)
	{
	  super(p,r);
	  height=h;	
	}
	Cylinder(int x,int y,int r,int h)
	{
		super(x,y,r);
		height=h;
	}
 	int getHeight()
	{
		return height;
	}
	double volume()
	{     return height*super.area();
	  	//return Math.PI*r*r*height;
	}
	double surfaceArea()
	{
	  return (2*Math.PI*r*r+2*Math.PI*r*height); 	
	}
	public boolean equals(Cylinder c)
	{
		return center.equals(c.center)&&c.r==r&&c.getHeight()==height;
	}
	public String toString()
	{
	  return 	super.toString()+"the heigth is "+height;
	}
}