2018/12/12
设计四个类,分别如下: [必做题]
3.1 设计Shape表示图形类,有面积属性area、周长属性per,颜色属性color,
有两个构造方法(一个是默认的、一个是为颜色赋值的),还有3个抽象方法,分别是:
getArea计算面积、getPer计算周长、showAll输出所有信息,还有一个求颜色的方法getColor。
3.2 设计 2个子类:
3.2.1 Rectangle表示矩形类,增加两个属性,Width表示长度、height表示宽度,
重写getPer、getArea和showAll三个方法,另外又增加一个构造方法(一个是默认的、一个是为高度、宽度、颜色赋值的)。
3.2.2 Circle表示圆类,增加1个属性,radius表示半径,重写getPer、getArea和showAll三个方法,
另外又增加两个构造方法(为半径、颜色赋值的)。
3.3 测试类中,在main方法中,声明创建每个子类的对象,并调用2个子类的showAll方法。
public abstract class Shape {
private double area;
private double per;
private String color;
public double getArea() {
return area;
}
public void setArea(double area) {
this.area = area;
}
public double getPer() {
return per;
}
public void setPer(double per) {
this.per = per;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public Shape(String color) {
this.color = color;
}
public abstract double getArea1();
public abstract double getPer1();
public abstract void showAll();
public void getColor1() {
System.out.println("颜色为: " + color);
}
}
public class Rectangle extends Shape {
private int width;
private int height;
public Rectangle(String color, int width, int height) {
super(color);
this.width = width;
this.height = height;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
@Override
public double getArea1() {
int area = width * height;
super.setArea(area);
return area;
}
@Override
public double getPer1() {
int per = 2 * (width + height);
super.setArea(per);
return per;
}
@Override
public void showAll() {
System.out.print("矩形的周长为: " + getPer1() + " 面积为: " + getArea1() + " 颜色为: " + getColor());
System.out.println();
}
}
public class Circle extends Shape {
private int radius;
public Circle(String color, int radius) {
super(color);
this.radius = radius;
}
public int getRadius() {
return radius;
}
public void setRadius(int radius) {
this.radius = radius;
}
@Override
public double getArea1() {
double area = Math.PI * radius * radius;
super.setArea(area);
return area;
}
@Override
public double getPer1() {
double per = Math.PI * 2 * radius;
super.setArea(per);
return per;
}
@Override
public void showAll() {
System.out.println("圆的周长为: " + getPer1() + " 面积为: " + getArea1() + " 颜色为: " + getColor());
}
}
public class Test {
public static void main(String[] args) {
Shape rectangle = new Rectangle("black", 10, 20);
Shape circle = new Circle("red", 15);
rectangle.showAll();
circle.showAll();
}
}