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public class Shape { protected String color; public void printColor(){     System.out.println ("颜色是:"+color); } public Shape (String color){     this.color = color public Shape() { } } public class Circle extends Shape{     private double radius; public Circle() { radius = 0; } public Circle (double radius,string color) {     this. radius = radius;     this color = color; } public double getRadius () {  return radius; } public void setRadius (double radius) {     this. radius = radius; } public double getPerimeter() { return 2 * Math.PI * radius; } public double getArea() {     return Math.PI * radius * radius; } void disp(){ System . out.println("圆的周长为: "+ getPer imeter());