Using Regex to validate CNPJ number

This regular expressions matches CNPJ number. CNPJ is a Registration Number of Brazilian Companies.

REPORT ZADN_SAMPLE.

*----------------------------------------------------------------------*
* -> CLASS cl_regex_test DEFINITION
*----------------------------------------------------------------------*
CLASS cl_regex_test DEFINITION FINAL.

  PUBLIC SECTION.

    METHODS : check_cnpj IMPORTING p_cnpj TYPE string.

  PRIVATE SECTION.

    DATA: o_regex   TYPE REF TO cl_abap_regex,
          o_matcher TYPE REF TO cl_abap_matcher.

ENDCLASS.                    "cl_regex_test DEFINITION

*----------------------------------------------------------------------*
* -> CLASS cl_regex_test IMPLEMENTATION
*----------------------------------------------------------------------*
CLASS cl_regex_test IMPLEMENTATION.

  METHOD check_cnpj.

* Create the regular expression:

    CREATE OBJECT o_regex
      EXPORTING
        pattern = '\d{2}.?\d{3}.?\d{3}/?\d{4}-?\d{2}'.

* Check to see if the CNPJ number matches the regular expression:

    CREATE OBJECT o_matcher
      EXPORTING
        regex = o_regex
        text  = p_cnpj.

    IF o_matcher->match( ) NE abap_true.

      MESSAGE 'Enter valid CNPJ number...' TYPE 'E'.

    ELSE.

      MESSAGE 'This is a valid CNPJ number...' TYPE 'S'.

    ENDIF.

  ENDMETHOD.                    "check_cnpj

ENDCLASS.                    "cl_regex_test IMPLEMENTATION

************************************************************************
************************************************************************
*                                                                      *
*                           PROGRAM FLOW LOGIC                         *
*                                                                      *
************************************************************************

START-OF-SELECTION.

  DATA : ocl_regex_test TYPE REF TO cl_regex_test.

  CREATE OBJECT ocl_regex_test.

  ocl_regex_test->check_cnpj( '12.043.129/0001-98' ). " IS VALID

  "ocl_regex_test->check_cnpj( '02.025.659/0001-981' ). " IS INVALID