Roland Turner

This comes up pretty frequently and seems like an odd omission from the standard library, particularly given that String now has split(). Most attempts are a little untidy, here’s the simplest expression of it that I could come up with:

public static String join(String separator, Object... items)
  {
  StringBuffer result = new StringBuffer();

  for (Object item : items)
    {
    if (result.length() > 0)
      result.append(separator);

    result.append(item);
    }

  return result.toString();
  }

There is a theoretical performance improvement to be had in not repeatedly calling length() but without an actual bottleneck situation to solve, I’d err on the side of simplicity.