4109阅读以下说明和Java代码,填充程序中的空缺,将解答填入答题纸的对应栏内。【说明】某应急交通控制系1613

阅读以下说明和Java代码,填充程序中的空缺,将解答填入答题纸的对应栏内。 【说明】 某应急交通控制系统(TraficControIS,stem)在红灯时控制各类车辆(Vehicle)的通 行,其类图如图6-1所示,在紧急状态下应急车辆在红灯时可通行,其余车辆按正常规 则通行。 下面的Java代码实现以上设计,请完善其中的空缺。 【Java代码】 abstract class Vehicle public Vehicle () { } abstract void run }; interface Emergency { (1) ; (2) ; } class Car extends Vehicle { public Car () { } void run () { } }; class Truck extends Vehicle { public Truck () { } void run () { } class PoliceCar (3) boolean isEmergency = false; public PoliceCar () { } public PoliceCar(boolean b) { this . isEmergency =b; } public boolean isEmergent () { return (4); } public void runRedLight () { } } public class TraficControISystem {/。交通控制类。/ private Vehicle[ ]V=new Vehiele [24]; int numVehicles; public void control() { for (int i=0; i<numVehicles; i++) { if (v[i] instanceof Enu rgency&& ((Emergency)V [i]) isEmergent()) { (5 ) . runRedLigh&39;: () ; }else (6).run() } } void add (Vehicle vehicle) { v[numVehicles++]=vehicle;)/*添加车辆*/ void shutDown()(/*代码略*/} public static void main (Stri.ng [ ] args) { TraficControlSystem tcs = new TraficControlSystem() ; tcs . add (new Car () ; tcs .add (new PoliceCar () ; tcs .add (new Ambulance () ; tcs . add (new Ambulance (true》 ; tcs . add (new FireEngine (true》 ; tcs . add (new Truck () ; tcs . add (new FireEngine () ; tcs . control () ; tcs . shutDown () ; } } 请帮忙给出正确答案和分析,谢谢!

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