Why does the code compare the order type using != instead of equals?

In Java, the != operator compares object references, while the equals() method compares the contents of objects. If in the code the comparison of the order type is done using !=, it is most likely that the order type is an enumeration (enum). For enums, comparison using != or == is safe and preferred because each enum element is a singleton, and comparing them by reference is correct and faster.

Example:

enum OrderType { ONLINE, OFFLINE }

OrderType type = OrderType.ONLINE;
if (type != OrderType.OFFLINE) {
    // logic
}

If equals() were used, it would be redundant and less efficient. For strings and other objects, it is better to use equals().