OOPS ABAP: Exception class without Message class

Exception Class:

• Exception is a problem that arises during the execution of the program.
•  The purpose of exception class is to raise and handle the exceptions.
•  We use TRY block to raise the exception and CATCH block to handle the exception.
•  The exception class name must start with CX.
•  CX_ROOT is the global class(Parent class) for all the exceptions.

There are 3 sub classes for parent class CX_ROOT.
1.CX_STATIC_CHECK - It is checked by both the compiler and runtime systems.
2.CX_DYNAMIC_CHECK - It is checked only at run time.
3.CX_NO_CHECK - It is not checked either by compiler or run time systems.

Note: While creating the exception class,system by default provide CX_STATIC_CHECK as the super class.

Example:

Steps:

• Go to se24 and enter class name.(Eg: ZCX_STU).
• Select radio button ' Exception class' and Uncheck the check box 'with messages of message classes as exception texts'.
• Press enter.
  

 

•  Click on 'Attributes' tab and enter variable lv_id.

 

• Enter exception ID and text.

•  Click on check and activate.

Using Exception class in program:

 

*&---------------------------------------------------------------------*
*& Report ZVB_STU_EXC_CLS
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
REPORT zvb_stu_exc_cls.

*TABLES: zvb_stu.
PARAMETERS:p_id TYPE zvb_stu-zstu_id.

DATA:lv_id   TYPE zstu_id,
     lv_name TYPE zstu_name,
     lv_dep  TYPE zstu_dep.

DATA:lo_exception TYPE REF TO zcx_stu,
     lv_msg       TYPE string.

AT SELECTION-SCREEN.
  TRY.
      IF p_id IS INITIAL.
        RAISE EXCEPTION TYPE zcx_stu
          EXPORTING
            textid = zcx_stu=>zcx_mandt
*           previous =
          .
      ENDIF.

    CATCH zcx_stu INTO lo_exception.
      CALL METHOD lo_exception->if_message~get_text
        RECEIVING
          result = lv_msg.
      MESSAGE lv_msg TYPE 'E'.

  ENDTRY.
  
  TRY.
      SELECT SINGLE zstu_id zstu_name zstu_dep
        FROM zvb_stu
        INTO ( lv_id,lv_name,lv_dep )
        WHERE zstu_id = p_id.
      IF sy-subrc <> 0.
        RAISE EXCEPTION TYPE zcx_stu
          EXPORTING
            textid = zcx_stu=>zcx_stu
*           previous =
            lv_id = p_id
          .
      ENDIF.

    CATCH zcx_stu INTO lo_exception.

      CALL METHOD lo_exception->if_message~get_text
        RECEIVING
          result = lv_msg.
      MESSAGE lv_msg TYPE 'E'.
  ENDTRY.

  START-OF-SELECTION.
  WRITE: LV_ID,
        / LV_NAME,
        / LV_DEP.