Join strings with different last delimiter

Question

Using stream.collect(Collectors.joining(\", \")) I can easily join all the strings of my stream delimited by a comma. A possible result would be \"a, b, c

Answer 1

This is not a Streams-API solution but is pretty fast. Enjoy!

public static final  String join(
    Iterable objects, String separator, String lastSeparator) 
{
    Objects.requireNonNull(objects);

    final String sep = separator == null ? "" : separator;
    final String lastSep = lastSeparator == null ? sep : lastSeparator;

    final StringBuilder builder = new StringBuilder();

    final Iterator iterator = objects.iterator();
    while (iterator.hasNext()) {
        final E next = iterator.next();
        if (builder.length() > 0) {
            if (iterator.hasNext()) {
                builder.append(sep);
            }
            else {
                builder.append(lastSep);
            }
        }
        builder.append(next);
    }

    return builder.toString();
}