How to remove duplicates from a list?

Question

I want to remove duplicates from a list but what I am doing is not working:

List<Customer> listCustomer = new ArrayList<Customer>();    
for (Customer customer: tmpListCustomer)
{
  if (!listCustomer.contains(customer)) 
  {
    listCustomer.add(customer);
  }
 }

Answer 1

Assuming you want to keep the current order and don't want a Set, perhaps the easiest is:

List<Customer> depdupeCustomers =
    new ArrayList<>(new LinkedHashSet<>(customers));

If you want to change the original list:

Set<Customer> depdupeCustomers = new LinkedHashSet<>(customers);
customers.clear();
customers.addAll(dedupeCustomers);