Java VM 初始化期间发生错误无法为对象堆预留足够 space

Question

这是我的代码：

import java.util.LinkedList;
import java.util.Scanner;
import java.util.InputMismatchException;
import java.util.*;




class Customer {
       public String lastName;
       public String firstName;
       public Customer() {
       }
       public Customer(String last, String first) {
          this.lastName = last;
          this.firstName = first;
       }
       public String toString() {
          return firstName + " " + lastName;
       }
    }
    class HourlyCustomer extends Customer {
       public double hourlyRate;
       public HourlyCustomer(String last, String first) {
          super(last, first);
       }
    }

class GenQueue<E> {
   private LinkedList<E> list = new LinkedList<E>();
   public void enqueue(E item) {
      list.addLast(item);
   }
   public E dequeue() {
      return list.poll();
   }
   public boolean hasItems() {
      return !list.isEmpty();
   }
   public boolean isEmpty()
   {
      return list == null;
   }
   public E removeFirst(){
       return list.removeFirst();
   }
   public E getFirst(){
       return list.getFirst();
   }
   public int size() {
      return list.size();
   }

   public void addItems(GenQueue<? extends E> q) {
      while (q.hasItems()) list.addLast(q.dequeue());
   }
}





public class something {

    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String input1;
        String input2;
        int choice = 1000;



        GenQueue<Customer> empList;
        empList = new GenQueue<Customer>();
        GenQueue<HourlyCustomer> hList;
        hList = new GenQueue<HourlyCustomer>(); 

        do{
            System.out.println("================");
            System.out.println("Queue Operations Menu");
            System.out.println("================");
            System.out.println("1,Enquene");
            System.out.println("2,Dequeue");
            System.out.println("0, Quit\n");
            System.out.println("Enter Choice:");
            try{

                choice = sc.nextInt();



                switch(choice){
                case 1:

                    do{


                    System.out.println("\nPlease enter last name:  ");
                    input1 = sc.next();
                    System.out.println("\nPlease enter first name:  ");
                    input2 = sc.next();
                    hList.enqueue(new HourlyCustomer(input1, input2));
                    empList.addItems(hList);

                    System.out.println("\n"+(input2 + " " +  input1) + " is successful queued");

                    System.out.println("\nDo you still want to enqueue?<1> or do you want to view all in queue?<0> or \nBack to main menu for dequeueing?<menu>: ");
                    choice = sc.nextInt();

                    }while (choice != 0);



                     System.out.println("\nThe customers' names are: \n");

                     while (empList.hasItems()) {
                     Customer emp = empList.dequeue();
                     System.out.println(emp.firstName + " " + emp.lastName + "\n" );
                     int choose=100;
                     System.out.println("\nGo back to main?<1=Yes/0=No>: \n");
                     choose = sc.nextInt();

                     if(choose == 1){
                         continue;
                     }
                     else
                     {
                         break;
                     }


                  }
                    break;

                case 2:


                    if (empList.isEmpty()) {
                        System.out.println("The queue is empty!");
                    }
                    else{
                    System.out.println("\nDequeued customer: "  +empList.getFirst());
                    empList.removeFirst();

                    System.out.println("\nNext customer in queue: "  +empList.getFirst()+"\n");

                    }
                    break;





                default:
                        System.out.println("Invalid choice");
                }

            }
            catch(InputMismatchException e){
                System.out.println("Please enter 1-5, 0 to quit");
                sc.nextLine();
            }
        }while(choice != 0);
    }
}

当我在case 1中添加if-else语句时出现了这个问题，我希望它在用户输入1时返回到main。我该如何解决这个问题？是否有替代此 if-else 语句的替代方法，以便它不会导致错误？第一天使用java，这里是新手，我需要一些帮助。

Error occurred during initialization of VM Could not reserve enough space for object heap

Answer 1

这个问题是由于JVM无法预留足够的内存space，这意味着你的OS 没有足够的内存来启动 JVM，此内存由 JAVA_OPTS vmargs 参数设置。

您可以尝试减少-Xmx和-Xms指定的内存。

有关以下内容的更多信息：Xms、Xmx

What are the Xms and Xmx parameters when starting JVMs?

Java VM 初始化期间发生错误无法为对象堆预留足够 space

Java Error occurred during initialization of VM Could not reserve enough space for object heap

java

virtual-machine

large-object-heap