jakarta regexp (java strutsÕýÔò±í´ïʽ)

  Character Classes
      [abc]                  Simple character class
      [a-zA-Z]               Character class with ranges
      [^abc]                 Negated character class
NOTE: Incomplete ranges will be interpreted as "starts from zero" or "ends with last character".
I.e. [-a] is the same as [\\u0000-a], and [a-] is the same as [a-\\uFFFF], [-] means "all characters".
  Standard POSIX Character Classes
      [:alnum:]              Alphanumeric characters.
      [:alpha:]              Alphabetic characters.
      [:blank:]              Space and tab characters.
      [:cntrl:]              Control characters.
      [:digit:]              Numeric characters.
      [:graph:]              Characters that are printable and are also visible.
                           (A space is printable, but not visible, while an