/** * Joins array elements to string. * * @param arr Array. * @return String. */ @Nullable public static String compactArray(Object[] arr) { if (arr == null || arr.length == 0) return null; String sep = ", "; StringBuilder sb = new StringBuilder(); for (Object s : arr) sb.append(s).append(sep); if (sb.length() > 0) sb.setLength(sb.length() - sep.length()); return U.compact(sb.toString()); }