Design Patterns and Best Practices in Java

copyOf method for collections

The copyOf method is introduced to create an unmodifiable copy of collections. For example, suppose you have a list and you need an immutable or unmodifiable copy, you can use the copyOf function. If you have used collections, you may wonder how it is different than Collections.unmodifiableCollection, which promises to do the same thing, that is create an unmodifiable copy of the collection. Well, although both methods give us an unmodifiable copy, when we use copyOf on a collection, say a list, it returns a list that cannot further be modified plus any changes to the original list do not impact the copied list. On the other hand, Collections.unmodifiableCollection does return an unmodifiable list in the aforementioned ...