public static String concat(String[] array, String separator, int fromIndex, int toIndex) {
    StringBuilder buf = new StringBuilder();
    for (int i = fromIndex; i <= toIndex; i++) {
      if (buf.length() > 0)
        buf.append(separator);
      buf.append(array[i]);
    }
    return buf.toString();
  }
public static String concat ( String [ ] array , String separator , int fromIndex , int toIndex ) { StringBuilder buf = new StringBuilder ( ) ; for ( int i = fromIndex ; i <= toIndex ; i ++ ) { if ( buf . length ( ) > 0 ) buf . append ( separator ) ; buf . append ( array [ i ] ) ; } return buf . toString ( ) ; }
Concats elements in array between <tt>fromIndex</tt>, inclusive, to <tt>toIndex</tt>,
inclusive, inserting <tt>separator</tt> between them.