学习内容：以圆类 Circle 及立体图形类 Solid 为基础设计圆锥类 Cone

代码示例：

import java.util.Scanner;

class Point4{

private double x;

private double y;

public Point4(double x,double y) {

this.x=x;

this.y=y;

System.out.println("Point Constructor run");

}

public void setX(double x) {//设置x坐标

this.x=x;

}

public double getX(){//返回x坐标

return x;

}

public void setY(double y) {//设置y坐标

this.y=y;

}

public double getY(){//返回y坐标

return y;

}

public void show() {//显示点的坐标

System.out.println("Point(X="+x+",Y="+y+")");

}

}

abstract class Plane4 extends Point4{

public Plane4(double x, double y) {

super(x, y);

}

double length() {

return 0;

}

double area() {

return 0;

}

}

class Circle2 extends Plane2 {

public Circle2(double x, double y,double radius) {

super(x,y);

this.x=x;

this.y=y;

this.radius=radius;

System.out.println("Circle Constructorrun");

}

private double x;

private double y;

final double PI=3.14159;

private double radius;

public void setX(double x) {//设置x坐标

this.x=x;

}

public final double getX(){//返回x坐标

return x;

}

public void setY(double y) {//设置y坐标

this.y=y;

}

public final double getY(){//返回y坐标

return y;

}

public void setR(double r) {

radius=r;

}

public final double getR() {

return radius;

}

public final void show() {

System.out.println("Circle(Point("+x+","+y+"),Radius="+radius+")");

}

public final double area() {

double area=PI*radius*radius;

System.out.println("Area="+area);

return 0;

}

public final double length() {

double length=2*PI*radius;

System.out.println("Length="+length);

return 0;

}

}

abstract class Solid1 extends Circle{

private double x;

private double y;

private double radius;

public Solid1(double x, double y, double radius) {

super(x, y, radius);

this.x=x;

this.y=y;

this.radius=radius;

}

public double volume() {//计算体积

return 0;

}

public double s_Area() {//计算表面积

return 0;

}

}

public class Cone extends Solid1{

private double x;

private double y;

private double radius;

private double height;

public void setX(double x) {//设置x坐标

this.x=x;

}

public void setY(double y) {//设置y坐标

this.y=y;

}

public void setR(double r) {

radius=r;

}

public void setH(double height) {

this.height=height;

}

public double getH() {

return height;

}

public Cone(double x, double y, double radius,double height) {

super(x, y, radius);

this.x=x;

this.y=y;

this.radius=radius;

this.height=height;

System.out.println("Cone Constructorrun");

}

public final void show() {

System.out.println("Cone(Circle(Point("+x+","+y+"),Radius="+radius+"),Height="+height+")");

}

public final double s_Area() {

double l=Math.sqrt(radius*radius+height*height);

double sarea=PI*radius*(radius+l);

System.out.println("s_Area="+sarea);

return 0;

}

public final double volume() {

double volume=(1.0/3.0)*PI*radius*radius*height;

System.out.println("Volume="+volume);

return 0;

}

public static void main(String[] args) {

double h;

System.out.println("请输入h：");

Scanner sc=new Scanner(System.in);

h=sc.nextDouble();

Cone co1=new Cone(1,2,3,4);

Cone co2=co1;

co1.show();

System.out.println();

co1.area();

co1.length();

co1.s_Area();

co1.volume();

System.out.println("............................................................................................");

co2.setH(h);

co2.show();

System.out.println();

co2.area();

co2.length();

co2.s_Area();

co2.volume();

}

}

运行截图：

明天任务：异常处理