请定义一个交通工具(Vehicle)的类，其中有:  属性：速度(speed)，体积(size)等  方法：移动(move())，设置速度(setSpeed(int speed))，设置体积（s

vehicle类：

public class Vehicle {
int speed;
int size;

void  move() {

System.out.println("开始：");

}

 int getSpeed() {
return speed;

 }

void setSpeed(int speed) {
this.speed=speed;

}

int getSize() {
return size; 

}

void setSize(int size) {
this.size=size;

}

void speedUp() {
speed+=20;

}

void speedDown() {
speed-=30;

}

}

Test类：

public class TestVehicle {

public static void main(String[] args) {
// TODO Auto-generated method stub
Vehicle vehicle = new Vehicle();
vehicle.setSpeed(60);
vehicle.setSize(40);
vehicle.move();
System.out.println("自行车开始的速度:"+vehicle.getSpeed());
System.out.println("自行车的体积："+vehicle.getSize());
vehicle.speedUp();
System.out.println("自行车加速后速度为："+vehicle.getSpeed());
vehicle.speedDown();
System.out.println("自行车减速后的速度："+vehicle.getSpeed());

}

}