以Point类为基础，定义一个平面中的Circle类

public class Circle {
	int radius;
	int x;
	int y;
	public Circle(){
		radius=1;
		x=1;
		y=1;
	}
	public Circle(int radius,int x,int y ){
		this.radius=radius;
		this.x=x;
		this.y=y;
	}
	public void judgement(Circle C){
		if((radius==C.radius)&&(x==C.x)&&(y==C.y))
			System.out.println("c1和c2相重叠");
		else
			System.out.println("c1和c2不重叠");
	}
}

import java.util.*;
public class TestCircle {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Circle c1=new Circle();          //调用无参的构造函数
		System.out.println("c1圆的原点坐标是:("+c1.x+","+c1.y+"),c2圆的半径是:"+c1.radius);
		Scanner input=new Scanner(System.in);
		System.out.println("输入c2圆的半径r:");
		int r=input.nextInt();
		System.out.println("输入c2圆的横坐标x:");
		int x=input.nextInt();
		System.out.println("输入c2圆的纵坐标y:");
		int y=input.nextInt();
		Circle c2=new Circle(r,x,y);
		System.out.println("c2圆的原点坐标是:("+c2.x+","+c2.y+"),c2圆的半径是:"+c2.radius);
		c1.judgement(c2);
	}

}