question: public static String join ( Collection < ? > c , String delim ) { StringBuilder retval = new StringBuilder ( ) ; Iterator < ? > itr = c . iterator ( ) ; if ( itr . hasNext ( ) ) retval . append ( itr . next ( ) ) ; else return "" ; while ( itr . hasNext ( ) ) { retval . append ( delim ) ; retval . append ( itr . next ( ) ) ; } return retval . toString ( ) ; }
target:  Similar to perl's join() method on lists, but works with all collections.