Java 8 StringJoiner

StringJoiner was introduced in Java 8. It joins String separated by a delimiter, starting with a supplied prefix and ending with a supplied suffix.

Let us understand it by looking into the below examples.

Join Strings using only delimiter

Output:

Join String with delimiter, prefix and suffix

Output

Merging two joiners

Output

Using Collectors.joining

Output

Using String.join

The static method join of String internally uses StringJoiner.