package jiekou1;
public interface ShapePara
{
//定义常量PI
final double PI=3.14;
//定义抽象方法
//获得图形面积
double getArea();
//获得图形周长
double getCircumference();
}
package jiekou1;
public class Circle implements ShapePara {
//定义成员变量
public double radius;
public double x;
public double y;
//定义构造方法
Circle(double radius)
{
this.radius=radius;
this.x=0;
this.y=0;
}
//定义成员方法
//返回半径的值
double getRadius()
{
return radius;
}
//写入圆心的坐标
void setCenter(double x, double y)
{
this.x=x;
this.y=y;
}
//写入圆的半径
void setRadius(double radius)
{
this.radius=radius;
}
//完善得到面积和周长的方法
@Override
public double getArea() {
return PI*radius*radius;
}
@Override
public double getCircumference() {
return 2*PI*radius;
}
}
package jiekou1;
public class Shape
{
//成员变量
private ShapePara sp;
public ShapePara getSp() {
return sp;
}
public void setSp(ShapePara sp) {
this.sp = sp;
}
//定义成员方法获得图形面积
void getArea()
{
System.out.println(sp.getArea());
}
//定义成员方法获得图形周长
void getCircumference()
{
System.out.println(sp.getCircumference());
}
}
package jiekou1;
public class Rect extends Shape
{
//定义成员变量
private double a;
private double b;
public double getA() {
return a;
}
public void setA(double a) {
this.a = a;
}
public double getB() {
return b;
}
public void setB(double b) {
this.b = b;
}
void getArea()
{
System.out.println("矩形的面积为："+a*b);
}
}
package jiekou1;
public class Text_mianji {
public static void main(String[] args) {
Shape yy= new Shape();
//匿名对象
Circle cl= new Circle(5);
cl.setCenter(0, 1);
cl.setRadius(12);
yy.setSp(cl);
System.out.println("圆的圆心坐标为：("+cl.x+","+cl.y+")");
System.out.println("半径为："+cl.radius);
System.out.print("圆的面积为：");
yy.getArea();
System.out.print("圆的周长为：");
yy.getCircumference();
//实例化矩形对象
Rect re = new Rect();
re.setA(20);
re.setB(12.5);
System.out.println("矩形的长为："+re.getA()+" 矩形的宽为："+re.getB());
re.getArea();
}
}
