下列程序实现求圆形的面积,请仔细阅读程序,将下列空格补充完整。 _______(1)________ java.util.Scanner; public class TestCircle { public static void main(String[] args) { System.out.println("请输入圆的半径:"); Scanner sc=__________(2)__________; double radius=sc.nextDouble(); Circle circle=new Circle(radius); ________(3)__________(“面积:”+circle.getArea()); } } class Circle{ private double radius;//半径 public Circle(double radius){ this.radius=radius; } public double getArea(){ return ____ } }