程序一 InterfaceDemo
package hh;
public class InterfaceDemo {
public static void main(String[] args){
JuXing j=new JuXing(2,4);
System.out.println("矩形面积="+j.getArea()+"矩形周长"+j.getZhouchang());
YuanXing y=new YuanXing(3);
System.out.println("圆形面积="+y.getArea()+"圆形周长="+y.getZhouchang());
}
}
程序二 ShapeArea
package hh;
public interface ShapeArea {
public abstract double getArea();
public abstract double getZhouchang();
}
程序三 JuXing
package hh;
public class JuXing implements ShapeArea{
double s;
double l;
double a;
double b;
JuXing(double a,double b){
this.a=a;
this.b=b;
}
public double getArea(){
return s=a*b;
}
public double getZhouchang(){
return l=(a+b)*2;
}
}
程序四 YuanXing
package hh;
public class YuanXing implements ShapeArea{
double s1;
double l1;
double r;
final double PI=3.14;
YuanXing(double r){
this.r=r;
}
public double getArea(){
return s1=r*r*PI;
}
public double getZhouchang(){
return l1=r*PI*2;
}
}