(Note: the article is from 2019, but it is still relevant and interesting.)

If all you're doing is deduplicating string objects in order to save memory, the article makes a good case to use `HashMap` or `ConcurrentHashMap` instead of `String.intern`.

The reason to use `String.intern` is in the fairly narrow case where you want to use `==` to compare strings, and some of these strings originated as string literals in Java source code. Java specifies that string literals for equal strings are always the same Java object, even if they occur in different class files that are compiled separately. This is accomplished by interning the strings, and `String.intern` provides user-level access to this same intern pool.