java继承

package aa;
public class Vehicle {
    private int capacity;
    public Vehicle() {
        this.capacity = 2;
        System.out.println("执行交通工具类的无参构造方法。");
    }
    public Vehicle(int capacity) {
        this.capacity = capacity;
        System.out.println("执行交通工具的有参构造方法。");
    }
    public int getCapacity() {
        return capacity;
    }
    public void setCapacity(int capacity) {
        this.capacity = capacity;
    }
    public void print(){
        System.out.println("载客人数为："+this.capacity);
    }
}

package aa;
public class Car extends Vehicle{
    private int speed;

    public int getSpeed() {
        return speed;
    }
    public void setSpeed(int speed) {
        this.speed = speed;
    }
    public Car(){
        this.speed=0;
        System.out.println("执行汽车类的无参构造方法。");
    }
    public Car(int speed){
        super(22);
        this.speed=speed;
        System.out.println("执行汽车类的有参构造方法。");
    }
    public int speedup(int data){
        for(;data>0;data--){
        this.speed+=10;
        }
        return this.speed;
    }
    public int speeddown(int data){
        for(;data>0;data--){
        this.speed-=15;
        }
        return this.speed;
    }
    public void print (){
        System.out.println("速度："+this.speed+"载客量："+getCapacity());
    }
}

package bb;

import aa.Car;
public final class Bus extends Car{
private int capacity;
public Bus(){
this.capacity=20;
System.out.println(“执行公交车类的无参构造方法。”);
}
public Bus(int capacity){
super(50);
this.capacity=capacity;
System.out.println(“执行公交车类的有参构造方法。”);
}
public void print(){
System.out.println(“速度：”+getSpeed()+”载客量”+capacity+”父类的载客量”+getCapacity());
}
}

package bb;

import aa.Car;

public class Text {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Car car=new Car();
    car.speedup(5);
    car.print();
    car.speeddown(2);
    car.print();
    Bus bus=new Bus(20);
    bus.print();
}

}
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