​Car类

public class Car {

private String color;

private String userName;

public Car() {

}

public Car(String color, String userName) {

this.setColor(color);

this.setUserName(userName);

}

public String getColor() {

return color;

}

public void setColor(String color) {

this.color = color;

}

public String getUserName() {

return userName;

}

public void setUserName(String userName) {

this.userName = userName;

}

public void use() {

System.out.println("我是机动车！");

}

public boolean equals(Object obj) {

if (obj == null)

return false;

Car temp = (Car) obj;

if ((this.getColor().equals(temp.getColor())) && (this.getUserName().equals(temp.getUserName())))

return true;

else

return false;

}

}

Taxi类

public class Taxi extends Car {

private String company;

    public Taxi() {

     }

public Taxi(String color, String userName, String company) {

super(color, userName);

this.setCompany(company);

}

public String getCompany() {

return company;

}

public void setCompany(String company) {

this.company = company;

}

final void ride() {

System.out.println(this.getUserName() + "的出租车是所属于" + this.getCompany() + "公司的。");

}

public void use() {

System.out.println("出租车是提高市民生活质量的重要条件之一。");

}

public String toString() {

return "taxi的信息是:" + this.getUserName() + "拥有一辆" + this.getColor() + "的出租车。";

}

}

HomeCar类

public final class HomeCar extends Car {

private int num;

public HomeCar() {

}

public HomeCar(String color, String userName, int num) {

super(color, userName);

this.setNum(num);

}

public int getNum() {

return num;

}

public void setNum(int num) {

this.num = num;

}

public void display() {

System.out.println(this.getUserName() + "拥有的" + this.getColor() + "颜色的私家车有" + this.getNum() + "个座位");

}

public void display(int num) {

System.out.println("家用汽车大多有" + num + "个座位。");

}

}

Test类

public class Test {

public static void main(String[] args) {

// 实例化父类对象，并传入两组相同的属性值

Car car1 = new Car("黑色", "小张");

Car car2 = new Car("黑色", "小张");

// 调用父类use方法

car1.use();

// 通过重写equals方法，比较两个对象是否相等

System.out.println("car1和car2的引用比较：" + car1.equals(car2));

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

// 实例化子类Taxi对象，并传入属性值

Taxi taxi = new Taxi("蓝色", "张小泉", "长生公司");

// 调用ride和use方法

taxi.ride();

taxi.use();

// 输出重写toString后的taxi信息

System.out.println(taxi.toString());

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

// 实例化子类HomeCar对象，并传入属性值

HomeCar homeCar = new HomeCar("紫色", "孙二娘", 7);

// 调用display方法及它的重载方法

homeCar.display();

homeCar.display(5);

}

}