ArrayList occurance of object type

I have a class of orders and I want to see how many times a unique customerNumber will get mapped to a status reading "On Hold"

public class Orders {
private String status = null;
private int customerNumber = 0;

public Orders(String status, int customerNumber) {
	super();
	this.status = status;
	this.customerNumber = customerNumber;
}
}




public int NumberOfOrdersOnHold(List<Orders> orders) {
	int sum = 0;
	for (Orders o : orders) {
		if(o.getStatus().contentEquals("On Hold"));
	}
	
}

I was thinking a counter method would work but it wouldnt. how will i achieve this method.I need numbers of orders in hold for each customerNumber not the total number.

You can use a Map! Try something like this:

public Map<Integer, Integer> numberOfOrdersOnHold(List<Orders> orders) {
    final Map<Integer, Integer> map = new HashMap<>();
    for (Orders o : orders) {
        int currentNumber = o.getCustomerNumber();

        // if map doesn't contain the key to the corresponding customer, were gonna add it
        if (!map.containsKey(currentNumber)) {
            map.put(currentNumber, 0);
        }

        // if the status is "On hold", increment the counter to the current customer
        if ("On hold".equals(o.getStatus())) {
            map.put(currentNumber, map.get(currentNumber) + 1);
        }
    }
    return map;
}

Do it as follows:

import java.util.List;
enum OrderStatus {
ONHOLD("On Hold"), APPROVED("Approved"), DELIVERED("Delivered");
private final String statusCode;
private OrderStatus(String statusCode) {
this.statusCode = statusCode;
}
}
class Order {
private OrderStatus status = null;
private int customerNumber = 0;
public Order(OrderStatus status, int customerNumber) {
this.status = status;
this.customerNumber = customerNumber;
}
public OrderStatus getStatus() {
return status;
}
public void setStatus(OrderStatus status) {
this.status = status;
}
public int getCustomerNumber() {
return customerNumber;
}
public void setCustomerNumber(int customerNumber) {
this.customerNumber = customerNumber;
}
@Override
public String toString() {
return "Order [status=" + status + ", customerNumber=" + customerNumber + "]";
}
}
public class Main {
public static void main(String[] args) {
List<Order> orders = List.of(new Order(OrderStatus.ONHOLD, 1234), new Order(OrderStatus.APPROVED, 1234),
new Order(OrderStatus.ONHOLD, 2345), new Order(OrderStatus.APPROVED, 1234),
new Order(OrderStatus.ONHOLD, 1234), new Order(OrderStatus.ONHOLD, 2345));
System.out.println("Customer#1234 has " + numberOfOrdersOnHold(orders, 1234) + " order(s) on hold");
}
static int numberOfOrdersOnHold(List<Order> orders, int customerNumber) {
int count = 0;
for (Order order : orders) {
if (order.getCustomerNumber() == customerNumber && order.getStatus() == OrderStatus.ONHOLD) {
count++;
}
}
return count;
}
}

Output:

Customer#1234 has 2 order(s) on hold

Notes:

1. Use enum for status values as it makes easy for you to write and maintain the code. Check this to learn more about Java enum.
2. Follow Java naming conventions e.g. NumberOfOrdersOnHold should be named as numberOfOrdersOnHold.
3. The function, numberOfOrdersOnHold also requires the customer number whose order status has to be found.