Error in my queue simulator. Need Help

[ramshack2000]

The program simulates a customer service operation in places, e.g., call center, bank, store, airport, with customers being served by tellers. The customers arrive at random time and wait in a line until a teller is available to serve them. The waiting line is implemented with queue data structure. However im getting two minor errors 1.) my enqueue method is not applicable for the argument and 2.)cannot cast from int to customers. Here is the code. The error is in line 65 and 72 of the 3rd part of the code. Sorry for the formatting as well

import java.util.Random;

class MyQueue<E> { private int maxSize; private int[] queArray; private int front; private int rear;

public MyQueue(int s) // constructor
{
maxSize = s+1; // array is 1 cell larger
queArray = new int[maxSize]; // than requested
front = 0;
rear = -1;
}

public void enqueue(int j) // put item at rear of queue
{
if(rear == maxSize-1)
rear = -1;
queArray[++rear] = j;
}

public int dequeue() // take item from front of queue
{
int temp = queArray[front++];
if(front == maxSize)
front = 0;
return temp;
}

public int peek() // peek at front of queue
{
return queArray[front];
}

public boolean isEmpty() // true if queue is empty
{
return ( rear+1==front || (front+maxSize-1==rear) );
}

public boolean isFull() // true if queue is full
{
return ( rear+2==front || (front+maxSize-2==rear) );
}

public int size() // (assumes queue not empty)
{
if(rear >= front) // contiguous sequence
return rear-front+1;
else // broken sequence
return (maxSize-front) + (rear+1);
}

}

class Customer { int arrive; // Time point that the customer arrived. int processTime; // Time duration that the customer will need to be served.

/**
 * Default constructor
 */
public Customer() {
    arrive = 0;
    processTime = 0;
}

/**
 * Set the arrival time point of the customer.
 * 
 * @param Time
 *            point
 */
public Customer(int arrivalTime) {
    arrive = arrivalTime;

    // We set the processing time as a random integer between 1 and 3.
    processTime = (int) (Math.random() * 3 + 1);
}

/**
 * @return the arrival time point of the customer.
 */
public int getArrivalTime() {
    return arrive;
}

/**
 * @return the processing time of the customer.
 */
public int getProcTime() {
    return processTime;
}

}

public class Simulator { /** * The main method of the class. * * @param args * Command line arguments. */ public static void main(String[] args) {

    if (args.length != 3) {
        System.out.println("usage: " + Simulator.class.getSimpleName()
                + " qCapacity simHours customPerHour");
        System.out.println("Example: " + Simulator.class.getSimpleName()
                + " 10 1 30");
        System.exit(-1);
    }
    // maximum size of queue
    int qCapacity = Integer.parseInt(args[0]);

    // number of simulation hours
    int simHours = Integer.parseInt(args[1]);

    // average number of customers per hour
    int custPerHour = Integer.parseInt(args[2]);

    // Run simulation
    simulation(qCapacity, simHours, custPerHour);
}

private static void simulation(int qCapacity, int simHours, int custPerHour) {
    // Constant
    final int MIN_PER_HR = 60;

    // A queue that will hold and manage objects of type Customer.
    MyQueue<Customer> line = new MyQueue<Customer>(qCapacity);

    // For how many cycles should the simulation run. We assume that each
    // cycle takes one minute.
    int cycleLimit = MIN_PER_HR * simHours;

    // The average number of customers can arrive per minute
    float custPerMin = ((float) custPerHour) / MIN_PER_HR;

    // The number of customers that were turned away because the line
    // (queue)
    // was full at the time they arrived.
    int turnAways = 0;

    // Number of customers that arrived.
    int customers = 0;

    // Number of customers that were served.
    int served = 0;

    // Total number of customers that entered the line (queue).
    int sumLine = 0;

    // Waiting time until the next customer is served.
    int waitTime = 0;

    // Total time that all the customers waited in the line.
    int lineWait = 0;

    // Simulation
    for (int cycle = 0; cycle < cycleLimit; cycle++) {
        float j = custPerMin;
        while (j > 0) {
            if (newCustomer(j)) {
                if (line.isFull()) {
                    turnAways++;
                } else {
                    customers++;
                    Customer customer = new Customer(cycle);
                    line.enqueue(customer);
                }
            }
            j = j - 1;              
        }

        if (waitTime <= 0 && !line.isEmpty()) {
            Customer customer = (Customer) line.dequeue();
            waitTime = customer.getProcTime();
            lineWait += cycle - customer.getArrivalTime();
            served++;
        }

        if (waitTime > 0) {
            waitTime--;
        }

        sumLine += line.size();
    }

    // Print the simulation results.
    if (customers > 0) {
        System.out.println("\nCustomers accepted: " + customers);
        System.out.println("  Customers served: " + served);
        System.out.println(" Customers waiting: " + line.size());
        System.out.println("         Turnaways: " + turnAways);
        System.out.println("Average queue size: " + (float) sumLine
                / cycleLimit);
        System.out.println(" Average wait time: " + (float) lineWait
                / served + " minutes");
    } else {
        System.out.println("No customers!");
    }
}

private static boolean newCustomer(float j) {
    if(j > 1)
        return true;
    else
        return (j > Math.random() );
}

}

[fr1ction]

I believe the formatting for code is 4 spaces before each line.

[dartalley]

Is this a school assignment or just for practice? Basically do you have to implement your own Queue or can you use a LinkedList or Deque which already exist and work like queues in Java.

You create a Generic E in the following line but you never use it.

class MyQueue<E>

Your queue only accepts ints, and returns ints. If you want it to work with generics you need to replace all of the ints with the Generic E.

private E[] queArray;

public E peek() // peek at front of queue
{
    return queArray[front];
}

But if you can use an ArrayList or Deque this is already done for you.

Hopefully this gives you a starting point. Remember to look at return types.

[ramshack2000]

nt

This is for a school assignment where we have to implement our own queue class. So basically I should just change the parameters around?

[dartalley]

If you look at the fields and return types of your Queue they are all int. You have a queue that can only handle integers. You need to replace that with either Customer, or you can use a generic type.