Java 无效的数组显示

你好，我有以下任务：

我的问题是第四项的第一项作业。我规定用随机对象填充数组，但是，当我想在屏幕上显示这个数组时，我总是得到不同的结果。 我的代码：

接口本身：

interface VehicleAndWorkers
{
  String cars();
}

实现接口的第一个类：

   public class TaxiStation implements VehicleAndWorkers{
   TrucksLogistic trucks = new TrucksLogistic();

   public String[] cars = {"KIA", "Hyundai", "Volkswagen", "Lada", "Datsun", "Skoda"};
   int quantCars = 150;
   int workers = 300;

   public String cars() {
   System.out.println("List of models of our taxi fleet: ");
      for (int i = 0; i < cars.length; i++) {
           System.out.println(cars[i]);
       }
           return null;
   }

   @Override
     public boolean equals(Object obj)
     {
       return trucks.quantTrucks == this.quantCars;
     }

    @Override
      public int hashCode() {
         return Objects.hash(trucks, quantCars);
      }

    @Override
      public String toString() {
           return cars();
       }
     }

public class TrucksLogistic implements VehicleAndWorkers {

String[] trucks = {"Kenworth W900", "Volvo FH16", "Scania R730", "MAN TGS 18.400", "МАЗ 6430", 
"КАМАЗ-5490 НЕО 2"};

int quantTrucks = 40;
int workers = 100;

public String cars()
{
    System.out.println("Our company model list: ");

    for (int i = 0; i < trucks.length; i++)
    {
        System.out.println(trucks[i]);
    }
    System.out.println("Amount of workers: " + workers);
    System.out.println("Number of trucks: " + quantTrucks);
    System.out.println("The ratio of the number of truck models to the number of trucks: " + 
      Math.round(trucks.length / quantTrucks));

    return null;
}

@Override
public String toString() {

    return cars();
 }
}

公共类出租车站实施车辆作业{
卡车物流卡车=新卡车物流（）；
公共字符串[]汽车={“起亚”、“现代”、“大众”、“拉达”、“达特桑”、“斯柯达”}；
int-quantCars=150；
国际工人=300；
公共小型车（）{
System.out.println（“我们的出租车车队模型列表：”）；
对于（int i=0；i

实现接口的第二个类：

   public class TaxiStation implements VehicleAndWorkers{
   TrucksLogistic trucks = new TrucksLogistic();

   public String[] cars = {"KIA", "Hyundai", "Volkswagen", "Lada", "Datsun", "Skoda"};
   int quantCars = 150;
   int workers = 300;

   public String cars() {
   System.out.println("List of models of our taxi fleet: ");
      for (int i = 0; i < cars.length; i++) {
           System.out.println(cars[i]);
       }
           return null;
   }

   @Override
     public boolean equals(Object obj)
     {
       return trucks.quantTrucks == this.quantCars;
     }

    @Override
      public int hashCode() {
         return Objects.hash(trucks, quantCars);
      }

    @Override
      public String toString() {
           return cars();
       }
     }

public class TrucksLogistic implements VehicleAndWorkers {

String[] trucks = {"Kenworth W900", "Volvo FH16", "Scania R730", "MAN TGS 18.400", "МАЗ 6430", 
"КАМАЗ-5490 НЕО 2"};

int quantTrucks = 40;
int workers = 100;

public String cars()
{
    System.out.println("Our company model list: ");

    for (int i = 0; i < trucks.length; i++)
    {
        System.out.println(trucks[i]);
    }
    System.out.println("Amount of workers: " + workers);
    System.out.println("Number of trucks: " + quantTrucks);
    System.out.println("The ratio of the number of truck models to the number of trucks: " + 
      Math.round(trucks.length / quantTrucks));

    return null;
}

@Override
public String toString() {

    return cars();
 }
}

公共级卡车物流实施车辆工人{
字符串[]卡车={“Kenworth W900”、“沃尔沃FH16”、“斯堪尼亚R730”、“曼恩TGS 18.400”、“МА3 6430”，
"КАМАЗ-5490 НЕО 2"};
int-quantTrucks=40；
国际工人=100；
公共小型车（）
{
System.out.println（“我们公司的型号列表：”）；
对于（int i=0；i<1.length；i++）
{
系统输出打印LN（卡车[i]）；
}
System.out.println（“工人数量：+工人”）；
System.out.println（“卡车数量：+quantTrucks”）；
System.out.println（“卡车型号与卡车数量的比率：”+
数学圆（卡车长度/数量卡车）；
返回null；
}
@凌驾
公共字符串toString（）{
归还车辆（）；
}
}

我试图在其中实现使用ArrayList（填充、显示等）的类：

公共类接口阵列{
ArrayList数组=新的ArrayList（）；
公共void setArray（）{
int randomLength=（int）数学地板（random（）*10）；
for（int i=0；i

那么，应用上一个类中的方法的类：

public class ConsoleInterface {
 void doChoice()
  {
    InterfaceArray interfaceArray = new InterfaceArray();

printOptions();

Scanner scan = new Scanner(System.in);
int choice = scan.nextInt();

while (choice >= 0 && choice < 5) {
    if (choice == 0) {
        interfaceArray.setArray();
        interfaceArray.getArray();
        printOptions();
        choice = scan.nextInt();
    }
    else if (choice == 1) {
        interfaceArray.setArray();
        printOptions();
        choice = scan.nextInt();
    }
    else if (choice == 2) {
        interfaceArray.sameElements();
        printOptions();
        choice = scan.nextInt();
    }
    else if (choice == 3) {
        interfaceArray.sameTypeElements();
        printOptions();
        choice = scan.nextInt();
    }
    else if (choice == 4) {
        interfaceArray.getArray();
        printOptions();
        choice = scan.nextInt();
    }
 }
}

void printOptions()
{
    System.out.println("Choose an action: \n");
    System.out.println("0 - Fill the array with random elements and display it on the screen. \n");
    System.out.println("1 - Fill the array with random elements. \n");
    System.out.println("2 - Find objects in the array,\n" +
            "      whose functional method returns the same result. \n");
    System.out.println("3 - Split the original array into two arrays, \n" +
                    "      which will store the same type of elements. \n");
    System.out.println("4 - Display the array(-s) to the screen.\n");
    System.out.println("Any key - Exit the application.\n");
 }
}

公共类控制台界面{
void docoice（）
{
InterfaceArray InterfaceArray=新InterfaceArray（）；
打印选项（）；
扫描仪扫描=新扫描仪（System.in）；
int choice=scan.nextInt（）；
而（选项>=0&&choice<5）{
如果（选项==0）{
interfaceArray.setArray（）；
interfaceArray.getArray（）；
打印选项（）；
choice=scan.nextInt（）；
}
else if（选项==1）