code: public static List<String> split(
                      final String str
                      )
      {
          String  s = str;
          if (s != null) {
              s = s.trim();
          }
  
          List<String>  list = new ArrayList<String>();
          if (s == null || s.length() == 0) {
              return list;
          }
  
          String[]  tokens = s.split( "[ \t\n\r\f]" );
          // NOTE: tokens[i] may be an empty string "".
  
          // excludes empty strings.
          for (String  t : tokens) {
              if (t.length() > 0) {
                  list.add( t );
              }
          }
  
          return list;
      }
docs: Splits the specified string.
  The string is divided around matches of the space character.
  The continuous space characters are counted as one.
  
  @return
  a list of the result strings.