topic Re: Using exceptions in SE24 global class Builder in Application Development and Automation Discussions

Using exceptions in SE24 global class Builder

Former Member — Thu, 10 Apr 2008 19:30:13 GMT

Hello all

I'm trying to learn how to use SE24 and I'm a bit stumped on handling exception.

Here's a trivial example showing what I'd like to do.

Can anyone tell me what's wrong. Or point me to a reference.


*& N1	TYPE INT1	Byte Value
*& N2	TYPE INT1	Byte Value
*& OUT	TYPE INT1	Byte Value
*& CX_SY_ARITHMETIC_ERROR		System Exception for Arithmetic Errors

METHOD mult2.
  data: exc type REF TO cx_sy_arithmetic_error .
  out = n1 * n2 .
  IF out > 9.
    RAISE EXCEPTION type exc
  ENDIF.
ENDMETHOD.

Re: Using exceptions in SE24 global class Builder

uwe_schieferstein — Thu, 10 Apr 2008 19:52:23 GMT

Hello Ed

Using exception classes the rule is the same as in Java:

Either THROW or CATCH the exception.

To catch means to surround the problematic piece of coding using a TRY-CATCH-ENDTRY block.

To throw means to define the exception class as part of the method signature.

The sample report ZUS_SDN_EXCEPTION_IN_LOCCLASS demonstrates how to throw and catch the exception.


*&---------------------------------------------------------------------*
*& Report  ZUS_SDN_EXCEPTION_IN_LOCCLASS
*&
*&---------------------------------------------------------------------*
*& Thread: Using exceptions in SE24 global class Builder
*& <a class="jive_macro jive_macro_thread" href="" __jive_macro_name="thread" modifiedtitle="true" __default_attr="817903"></a>
*&---------------------------------------------------------------------*

REPORT  zus_sdn_exception_in_locclass.


*----------------------------------------------------------------------*
*       CLASS lcl_myclass DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_myclass DEFINITION.
  PUBLIC SECTION.

    CLASS-METHODS:
      divide
        IMPORTING
          id_enumerator TYPE i
          id_denominator  TYPE i
        RETURNING
          value(rd_result)  TYPE i
        RAISING
          cx_sy_zerodivide.

ENDCLASS.                    "lcl_myclass DEFINITION



*----------------------------------------------------------------------*
*       CLASS lcl_myclass IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_myclass IMPLEMENTATION.

  METHOD divide.

    " raises division by zero error if id_denominator = 0
        rd_result = id_enumerator / id_denominator.

    " NOTE: since the exception class is defined within the
    "       method signature we do not need to catch it here.

    " BUT: Either catch or throw. Since we throw the exception class
    "      the caller of the method (= main program) must catch it.

  ENDMETHOD.                    "divide

ENDCLASS.                    "lcl_myclass IMPLEMENTATION


DATA: go_error      TYPE REF TO cx_root,
      gd_msg        TYPE bapi_msg.

DATA: go_myclass    TYPE REF TO lcl_myclass,
      gd_result     TYPE i.

PARAMETER:
  p_enum      TYPE i  DEFAULT '10',
  p_denom     TYPE i  DEFAULT '1'.

START-OF-SELECTION.


  TRY.
      CALL METHOD lcl_myclass=>divide
        EXPORTING
          id_enumerator  = p_enum
          id_denominator = p_denom
        RECEIVING
          rd_result      = gd_result.

      WRITE: / p_enum, '/', p_denom, '=', gd_result.

    CATCH cx_sy_zerodivide INTO go_error.
      gd_msg = go_error->get_text( ).
      MESSAGE gd_msg TYPE 'I'.
  ENDTRY.


END-OF-SELECTION.

Regards

Uwe

Re: Using exceptions in SE24 global class Builder

Former Member — Thu, 10 Apr 2008 20:09:29 GMT

Thanks for replying Uwe. I'm afraid I'm not asking the question correctly.

What I want to have is an "IF" or "CASE" statement in my method.

When the IF test is false, I want to RAISE an exception similar to what you'd do in a function module.

Re: Using exceptions in SE24 global class Builder

uwe_schieferstein — Thu, 10 Apr 2008 21:11:25 GMT

Hello Ed

I have modified my sample report to show both ways: classical exceptions and exception classes. However, since exception classes are much more powerful I recommend to use them instead of classical exceptions.

Please note that you cannot mix classical exceptions with exception classes in the same class. Therefore I inactivated method DIVIDE_3.


*&---------------------------------------------------------------------*
*& Report  ZUS_SDN_EXCEPTION_IN_LOCCLASS
*&
*&---------------------------------------------------------------------*
*& Thread: Using exceptions in SE24 global class Builder
*& <a class="jive_macro jive_macro_thread" href="" __jive_macro_name="thread" modifiedtitle="true" __default_attr="817903"></a>
*&---------------------------------------------------------------------*

REPORT  zus_sdn_exception_in_locclass.


*----------------------------------------------------------------------*
*       CLASS lcl_myclass DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_myclass DEFINITION.
  PUBLIC SECTION.

    CLASS-METHODS:
      " use exception class
      divide
        IMPORTING
          id_enumerator TYPE i
          id_denominator  TYPE i
        RETURNING
          value(rd_result)  TYPE i
        RAISING
          cx_sy_zerodivide,

      " use exception class
      divide_2
        IMPORTING
          id_enumerator TYPE i
          id_denominator  TYPE i
        RETURNING
          value(rd_result)  TYPE i
        RAISING
          cx_sy_zerodivide.


**      " use classical exception
**      divide_3
**        IMPORTING
**          id_enumerator TYPE i
**          id_denominator  TYPE i
**        RETURNING
**          value(rd_result)  TYPE i
**        EXCEPTIONS
**          arithmetic_error.


ENDCLASS.                    "lcl_myclass DEFINITION



*----------------------------------------------------------------------*
*       CLASS lcl_myclass IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_myclass IMPLEMENTATION.

  METHOD divide.

    " raises division by zero error if id_denominator = 0
    rd_result = id_enumerator / id_denominator.

    " NOTE: since the exception class is defined within the
    "       method signature we do not need to catch it here.

    " BUT: Either catch or throw. Since we throw the exception class
    "      the caller of the method (= main program) must catch it.

  ENDMETHOD.                    "divide


  METHOD divide_2.

    IF ( id_denominator = 0 ).
      RAISE EXCEPTION TYPE cx_sy_zerodivide
        EXPORTING
          textid = cx_sy_zerodivide=>cx_sy_arithmetic_error
          operation = 'DIVIDE'.

    ELSE.
      rd_result = id_enumerator / id_denominator.
    ENDIF.


  ENDMETHOD.                                                "divide_2


**  METHOD divide_3.
**    IF ( id_denominator = 0 ).
**      RAISE EXCEPTION arithmetic_error.
**    ELSE.
**      rd_result = id_enumerator / id_denominator.
**    ENDIF.
**  ENDMETHOD.                                                "divide_3

ENDCLASS.                    "lcl_myclass IMPLEMENTATION


DATA: go_error      TYPE REF TO cx_root,
      gd_msg        TYPE bapi_msg.

DATA: go_myclass    TYPE REF TO lcl_myclass,
      gd_result     TYPE i.

PARAMETER:
  p_enum      TYPE i  DEFAULT '10',
  p_denom     TYPE i  DEFAULT '1'.

START-OF-SELECTION.


**  TRY.
**      CALL METHOD lcl_myclass=>divide
**        EXPORTING
**          id_enumerator  = p_enum
**          id_denominator = p_denom
**        RECEIVING
**          rd_result      = gd_result.
**
**      WRITE: / p_enum, '/', p_denom, '=', gd_result.
**
**    CATCH cx_sy_zerodivide INTO go_error.
**      gd_msg = go_error->get_text( ).
**      MESSAGE gd_msg TYPE 'I'.
**  ENDTRY.


  TRY.
      CALL METHOD lcl_myclass=>divide_2
        EXPORTING
          id_enumerator  = p_enum
          id_denominator = p_denom
        RECEIVING
          rd_result      = gd_result.

      WRITE: / p_enum, '/', p_denom, '=', gd_result.

    CATCH cx_sy_zerodivide INTO go_error.
      gd_msg = go_error->get_text( ).
      MESSAGE gd_msg TYPE 'I'.
  ENDTRY.


**  CALL METHOD lcl_myclass=>divide_3
**    EXPORTING
**      id_enumerator    = p_enum
**      id_denominator   = p_denom
**    RECEIVING
**      rd_result        = gd_result
**    EXCEPTIONS
**      arithmetic_error = 1.
**  IF ( syst-subrc = 0 ).
**    WRITE: / p_enum, '/', p_denom, '=', gd_result.
**  ELSE.
**    MESSAGE 'Arithmetic error'  TYPE 'I'.
**  ENDIF.


END-OF-SELECTION.

Regards

Uwe

Re: Using exceptions in SE24 global class Builder

Former Member — Thu, 10 Apr 2008 21:31:10 GMT

Perfect. That REALLY helped a great deal.

Thanks so much.