Best way to join the String

StringDemo.java

import java.util.StringJoiner;
import java.util.stream.Stream;

public class StringDemo {
    public static void main(String[] args) {
        StringJoiner sj = new StringJoiner(",", "[", "]");

        Stream.of("1", "2", "3").forEach(sj::add);

        System.out.println(sj.toString());
    }
}

since Java 1.8