定义一个交通工具(Vehicle)的类,定义私有属性: 速度(speed)、方向(direction),定义方法:设置速度setSpeed(int 
speed))、改变速度changeSpeed(int speed),设置方向setDirection(int 
direction),改变速度changeDirection(int direction)。最后在测试类 Vehicle 中的 
main()中实例化一个交通工具对象direction:
1:North
2:South
3:East
4:West
输入:一行两个数
第一个数表示调用哪个方法(1:setSpeed 2:changeSpeed 3:setDirection 4:changeDirection)
第二个数表示输入的值
输出:方法名和私有属性的值
初始化速度为0,方向为North
例
输入:
1 1
输出:
setSpeed
speed = 1 direction = North
输入用例:
1 1
输出用例:
setSpeed
speed = 1 direction = North
输入用例:
2 1
输出用例:
changeSpeed
speed = 1 direction = North
输入用例:
3 2
输出用例:
setDirection
speed = 0 direction = South
以下为源码:
import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
            Vehicle vehicle=new Vehicle();
            int n=sc.nextInt();
            int m=sc.nextInt();
            switch (n){
                case 1:  System.out.println("setSpeed");
                        vehicle.setSpeed(m);
                        System.out.print("speed = "+vehicle.getSpeed()+" direction = North");
                        break;
                case 2:  System.out.println("changeSpeed");
                        vehicle.setSpeed(m);
                        System.out.print("speed = "+vehicle.getSpeed()+" direction = North");break;
                case 3:System.out.println("setDirection");
                    vehicle.setDirection(m);
                    System.out.print("speed = 0"+" direction = "+vehicle.str);
                    break;
                case 4:System.out.println("changeDirection");
                    vehicle.setDirection(m);
                    System.out.print("speed = 0"+" direction = "+vehicle.str);
                    break;
                }
    }
}
class Vehicle{
    private int speed=0;
    private int direction;
    String str;
    
    public void setSpeed(int speed){
        this.speed=speed;
    }
    public int getSpeed(){
        return speed;
    }
    public void setDirection(int direction){
        switch (direction){
        case 1:str="North";break;
        case 2:str="South";break;
        case 3:str="East";break;
        case 4:str="West";break;
    }
    }
    public void changeSpeed(int speed){
        this.speed=speed;
    }
    public void changeDirection(int direction){
            switch (direction){
        case 1:str="North";break;
        case 2:str="South";break;
        case 3:str="East";break;
        case 4:str="West";break;
    }   
    }
}