package text;
public class Vehicle {
private String brand;
private String color;
private double speed;
public Vehicle(String brand, String color, double speed) {
super();
this.brand = brand;
this.color = color;
this.speed = 0;
}
public String getBrand() {
return brand;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public double getSpeed() {
return speed;
}
public void setSpeed(double speed) {
this.speed = speed;
}
public void run(){
System.out.println("品牌是"+brand+",颜色是"+color+"的汽车,正在以"+speed+"速度奔跑");
}
}
package text;
public class Car extends Vehicle{
int loader;
public int getLoader() {
return loader;
}
public void setLoader(int loader) {
this.loader = loader;
}
public Car(String brand, String color, double speed, int loader) {
super(brand, color, speed);
this.loader = loader;
}
public void run(){
System.out.println("品牌是"+super.getBrand()+",颜色是"+super.getColor()+",载人数为"+loader+"的汽车,正在以"+super.getSpeed()+"速度奔跑");
}
}
package text;
public class test {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Vehicle v=new Vehicle("benz", "black", 120);
v.setSpeed(120);
v.run();
Car c=new Car("Honda", "red", 100, 2);
c.setSpeed(200);
c.run();
}
}![]()
设计三个类,分别如下:(知识点:抽象类及抽象方法) [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 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。
package text;
public class Shape {
double area;
double per;
String color;
public Shape() {
super();
}
public Shape( String color) {
super();
this.color = 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 void showAll(){
System.out.println("面积是"+area+"周长是"+per+"颜色是"+color);
}
}
package text;
public class Rectangle extends Shape {
double Width;
double height;
public double getper(){
return (Width + height) * 2;
}
public double getArea(){
return (Width * height);
}
public Rectangle( String color, double width,double height) {
super();
this.Width = width;
this.height = height;
this.color = color;
}
public Rectangle() {
super();
}
public void showAll(){
System.out.println("矩形的长是"+Width+" 矩形的宽是"+height+" 矩形的面积是"+getArea()+" 矩形的周长是"+getper()+"矩形的颜色是"+color);
}
}
package text;
public class Circle extends Shape {
double radius;
public double getper(){
return radius*3.14*2;
}
public double getArea(){
return radius*3.14*radius;
}
public void showAll(){
System.out.println("圆的半径是"+radius+"圆的周长是"+getper()+"圆的面积是"+getArea()+"圆的颜色是"+color);
}
public Circle(String color, double radius) {
super();
this.radius = radius;
this.color = color;
}
}
![]()