Here's my code:
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);
}
}
This problem occured when I added the if-else statement inside case 1, I wanted it to go back to main if the user inputs 1. How do I fix this? Is there an alternative to this if-else statement so that it would not cause the error? First day using java, newbie here, I need some help.
Error occurred during initialization of VM Could not reserve enough space for object heap
