对象中—练习9

Circle.java

package com.atguigu.exer3;

public class Circle extends GeometricObject {
	
	private double radius;

	public Circle() {
		super();
		radius = 1.0;
//		color = "white";
//		weight = 1.0;
	}

	public Circle(double radius) {
		super();
		this.radius = radius;
	}
	public Circle(double radius,String color,double weight) {
		super(color,weight);
		this.radius = radius;
	}

	public double getRadius() {
		return radius;
	}

	public void setRadius(double radius) {
		this.radius = radius;
	}
	//求圆的面积
	public double findArea(){
		return 3.14 * radius * radius;
	}
	//比较两个圆的半径是否相等，如相等，返回true。
	@Override
	public boolean equals(Object obj) {
		
		if(this == obj){
			return true;
		}
		
		if(obj instanceof Circle){
			Circle c = (Circle)obj;
			return this.radius == c.radius;
		}
		
		return false;
		
	}

	@Override
	public String toString() {
		return "Circle [radius=" + radius + "]";
	}
	
	
}

GeometricObject.java

package com.atguigu.exer3;

public class GeometricObject {
	
	protected String color;
	protected double weight;
	public GeometricObject() {
		super();
		this.color = "white";
		this.weight = 1.0;
	}
	public GeometricObject(String color, double weight) {
		super();
		this.color = color;
		this.weight = weight;
	}
	public String getColor() {
		return color;
	}
	public void setColor(String color) {
		this.color = color;
	}
	public double getWeight() {
		return weight;
	}
	public void setWeight(double weight) {
		this.weight = weight;
	}
	
	
	
}

CircleTest.java

package com.atguigu.exer3;
/*
 * 写一个测试类，创建两个Circle对象，判断其颜色是否相等；
 * 利用equals方法判断其半径是否相等；利用toString()方法输出其半径。
 */
public class CircleTest {
	public static void main(String[] args) {
		
		Circle circle1 = new Circle(2.3);
		Circle circle2 = new Circle(3.3, new String("white"), 2.0);
		
		System.out.println("颜色是否相等：" + circle1.getColor().equals(circle2.getColor()));
		
		System.out.println("半径是否相等：" + circle1.equals(circle2));
		
		System.out.println(circle1);
		System.out.println(circle2.toString());
		
	}
}