ABAP Exception Classes: Create Custom Exceptions

Category
ABAP-Statements
Published
Author
Johannes

Exception Classes enable structured error handling in ABAP. Custom exceptions (CX_ classes) transport error data, support multi-language texts and integrate seamlessly with TRY-CATCH.

Exception Hierarchy

CX_ROOT
  │
  ├── CX_STATIC_CHECK      " Must be declared (RAISING)
  │     └── CX_DYNAMIC_CHECK  " Can but doesn't have to be declared
  │
  └── CX_NO_CHECK          " Doesn't have to be declared (Runtime)
Base ClassRAISING requiredTypical Use
CX_STATIC_CHECKYesBusiness exceptions
CX_DYNAMIC_CHECKOptionalTechnical errors
CX_NO_CHECKNoCritical system errors

Creating Exception Classes

1. Simple Exception (SE24/ADT)

CLASS zcx_validation_error DEFINITION
  PUBLIC
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    " Interface for texts
    INTERFACES: if_t100_message.
    INTERFACES: if_t100_dyn_msg.


    " Constants for message texts
    CONSTANTS:
      BEGIN OF invalid_input,
        msgid TYPE symsgid VALUE 'ZMSG',
        msgno TYPE symsgno VALUE '001',
        attr1 TYPE scx_attrname VALUE 'MV_FIELD',
        attr2 TYPE scx_attrname VALUE '',
        attr3 TYPE scx_attrname VALUE '',
        attr4 TYPE scx_attrname VALUE '',
      END OF invalid_input.


    " Attributes for error data
    DATA: mv_field TYPE string READ-ONLY.


    " Constructor
    METHODS: constructor
      IMPORTING
        textid   LIKE if_t100_message=>t100key OPTIONAL
        previous LIKE previous OPTIONAL
        iv_field TYPE string OPTIONAL.


ENDCLASS.


CLASS zcx_validation_error IMPLEMENTATION.
  METHOD constructor.
    super->constructor( previous = previous ).


    mv_field = iv_field.


    CLEAR me->textid.
    IF textid IS INITIAL.
      if_t100_message~t100key = invalid_input.
    ELSE.
      if_t100_message~t100key = textid.
    ENDIF.
  ENDMETHOD.
ENDCLASS.

2. Exception with Multiple Texts

CLASS zcx_order_error DEFINITION
  PUBLIC
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    INTERFACES: if_t100_message.


    " Different error texts
    CONSTANTS:
      BEGIN OF order_not_found,
        msgid TYPE symsgid VALUE 'ZORDER',
        msgno TYPE symsgno VALUE '001',
        attr1 TYPE scx_attrname VALUE 'MV_ORDER_ID',
        attr2 TYPE scx_attrname VALUE '',
        attr3 TYPE scx_attrname VALUE '',
        attr4 TYPE scx_attrname VALUE '',
      END OF order_not_found,


      BEGIN OF order_already_shipped,
        msgid TYPE symsgid VALUE 'ZORDER',
        msgno TYPE symsgno VALUE '002',
        attr1 TYPE scx_attrname VALUE 'MV_ORDER_ID',
        attr2 TYPE scx_attrname VALUE 'MV_SHIP_DATE',
        attr3 TYPE scx_attrname VALUE '',
        attr4 TYPE scx_attrname VALUE '',
      END OF order_already_shipped,


      BEGIN OF invalid_quantity,
        msgid TYPE symsgid VALUE 'ZORDER',
        msgno TYPE symsgno VALUE '003',
        attr1 TYPE scx_attrname VALUE 'MV_QUANTITY',
        attr2 TYPE scx_attrname VALUE 'MV_MAX_QUANTITY',
        attr3 TYPE scx_attrname VALUE '',
        attr4 TYPE scx_attrname VALUE '',
      END OF invalid_quantity.


    " Attributes
    DATA: mv_order_id     TYPE string READ-ONLY,
          mv_ship_date    TYPE d READ-ONLY,
          mv_quantity     TYPE i READ-ONLY,
          mv_max_quantity TYPE i READ-ONLY.


    METHODS: constructor
      IMPORTING
        textid          LIKE if_t100_message=>t100key OPTIONAL
        previous        LIKE previous OPTIONAL
        iv_order_id     TYPE string OPTIONAL
        iv_ship_date    TYPE d OPTIONAL
        iv_quantity     TYPE i OPTIONAL
        iv_max_quantity TYPE i OPTIONAL.


ENDCLASS.


CLASS zcx_order_error IMPLEMENTATION.
  METHOD constructor.
    super->constructor( previous = previous ).


    mv_order_id = iv_order_id.
    mv_ship_date = iv_ship_date.
    mv_quantity = iv_quantity.
    mv_max_quantity = iv_max_quantity.


    CLEAR me->textid.
    IF textid IS INITIAL.
      if_t100_message~t100key = order_not_found.
    ELSE.
      if_t100_message~t100key = textid.
    ENDIF.
  ENDMETHOD.
ENDCLASS.

3. Raise Exception (RAISE EXCEPTION)

CLASS lcl_order_service DEFINITION.
  PUBLIC SECTION.
    METHODS: get_order
      IMPORTING iv_order_id TYPE string
      RETURNING VALUE(rs_order) TYPE ty_order
      RAISING   zcx_order_error.


    METHODS: ship_order
      IMPORTING iv_order_id TYPE string
      RAISING   zcx_order_error.
ENDCLASS.


CLASS lcl_order_service IMPLEMENTATION.
  METHOD get_order.
    " Search for order
    SELECT SINGLE * FROM ztorders
      WHERE order_id = @iv_order_id
      INTO @rs_order.


    IF sy-subrc <> 0.
      RAISE EXCEPTION TYPE zcx_order_error
        EXPORTING
          textid      = zcx_order_error=>order_not_found
          iv_order_id = iv_order_id.
    ENDIF.
  ENDMETHOD.


  METHOD ship_order.
    DATA: ls_order TYPE ty_order.


    ls_order = get_order( iv_order_id ).


    IF ls_order-status = 'SHIPPED'.
      RAISE EXCEPTION TYPE zcx_order_error
        EXPORTING
          textid       = zcx_order_error=>order_already_shipped
          iv_order_id  = iv_order_id
          iv_ship_date = ls_order-ship_date.
    ENDIF.


    " Process shipping...
  ENDMETHOD.
ENDCLASS.

4. Catch and Process Exception

DATA: lo_service TYPE REF TO lcl_order_service,
      ls_order   TYPE ty_order.


lo_service = NEW #( ).


TRY.
    ls_order = lo_service->get_order( '12345' ).


  CATCH zcx_order_error INTO DATA(lx_error).
    " Output error text
    DATA(lv_message) = lx_error->get_text( ).
    WRITE: / 'Error:', lv_message.


    " Access specific attributes
    WRITE: / 'Order ID:', lx_error->mv_order_id.


    " Re-throw error
    " RAISE EXCEPTION lx_error.
ENDTRY.

5. Exception Chain (PREVIOUS)

METHOD process_order.
  TRY.
      " Database operation
      validate_order( is_order ).


    CATCH zcx_validation_error INTO DATA(lx_val).
      " Pass original exception as PREVIOUS
      RAISE EXCEPTION TYPE zcx_order_error
        EXPORTING
          textid   = zcx_order_error=>order_not_found
          previous = lx_val
          iv_order_id = is_order-id.
  ENDTRY.
ENDMETHOD.




" When catching: Traverse chain
TRY.
    process_order( ls_order ).


  CATCH cx_root INTO DATA(lx_error).
    " Output all exceptions in the chain
    DATA(lx_current) = lx_error.


    WHILE lx_current IS BOUND.
      WRITE: / lx_current->get_text( ).
      lx_current = lx_current->previous.
    ENDWHILE.
ENDTRY.

6. Exception without Message Class

CLASS zcx_simple_error DEFINITION
  PUBLIC
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    " Simple text without T100
    DATA: mv_message TYPE string READ-ONLY.


    METHODS: constructor
      IMPORTING
        iv_message TYPE string OPTIONAL
        previous   LIKE previous OPTIONAL.


    METHODS: if_message~get_text REDEFINITION.


ENDCLASS.


CLASS zcx_simple_error IMPLEMENTATION.
  METHOD constructor.
    super->constructor( previous = previous ).
    mv_message = iv_message.
  ENDMETHOD.


  METHOD if_message~get_text.
    result = mv_message.
  ENDMETHOD.
ENDCLASS.




" Usage
RAISE EXCEPTION TYPE zcx_simple_error
  EXPORTING iv_message = 'An error occurred'.

7. COND/SWITCH with THROW

DATA: lv_age TYPE i VALUE -5.


" Throw exception in expression
DATA(lv_status) = COND string(
  WHEN lv_age >= 0 AND lv_age < 18 THEN 'Minor'
  WHEN lv_age >= 18 THEN 'Adult'
  ELSE THROW zcx_validation_error(
    textid   = zcx_validation_error=>invalid_input
    iv_field = 'AGE'
  )
).




" With SWITCH
DATA(lv_result) = SWITCH string( lv_status
  WHEN 'A' THEN 'Active'
  WHEN 'I' THEN 'Inactive'
  ELSE THROW zcx_validation_error( iv_field = 'STATUS' )
).

8. Local Exception Class

" For tests or local usage
CLASS lcx_local_error DEFINITION
  INHERITING FROM cx_static_check.


  PUBLIC SECTION.
    DATA: mv_info TYPE string READ-ONLY.


    METHODS: constructor
      IMPORTING iv_info TYPE string OPTIONAL
                previous LIKE previous OPTIONAL.


    METHODS: if_message~get_text REDEFINITION.
ENDCLASS.


CLASS lcx_local_error IMPLEMENTATION.
  METHOD constructor.
    super->constructor( previous = previous ).
    mv_info = iv_info.
  ENDMETHOD.


  METHOD if_message~get_text.
    result = |Local error: { mv_info }|.
  ENDMETHOD.
ENDCLASS.

9. Exception Hierarchy for Domain

" Base class for all order exceptions
CLASS zcx_order_base DEFINITION
  PUBLIC
  ABSTRACT
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    DATA: mv_order_id TYPE string READ-ONLY.


    METHODS: constructor
      IMPORTING iv_order_id TYPE string OPTIONAL
                previous LIKE previous OPTIONAL.
ENDCLASS.




" Specific exceptions
CLASS zcx_order_not_found DEFINITION
  PUBLIC
  INHERITING FROM zcx_order_base
  CREATE PUBLIC.
  " ...
ENDCLASS.


CLASS zcx_order_locked DEFINITION
  PUBLIC
  INHERITING FROM zcx_order_base
  CREATE PUBLIC.
  " ...
ENDCLASS.


CLASS zcx_order_invalid_state DEFINITION
  PUBLIC
  INHERITING FROM zcx_order_base
  CREATE PUBLIC.
  " ...
ENDCLASS.




" Catch by hierarchy
TRY.
    process_order( ).


  CATCH zcx_order_not_found INTO DATA(lx_not_found).
    " Specific handling


  CATCH zcx_order_locked INTO DATA(lx_locked).
    " Specific handling


  CATCH zcx_order_base INTO DATA(lx_order).
    " All other order exceptions


  CATCH cx_static_check INTO DATA(lx_other).
    " All other static exceptions


ENDTRY.

10. MESSAGE Integration

" Message class ZMSG with message 001:
" "Field & contains invalid value"


CLASS zcx_with_message DEFINITION
  PUBLIC
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    INTERFACES: if_t100_message.
    INTERFACES: if_t100_dyn_msg.


    CONSTANTS:
      BEGIN OF field_invalid,
        msgid TYPE symsgid VALUE 'ZMSG',
        msgno TYPE symsgno VALUE '001',
        attr1 TYPE scx_attrname VALUE 'MV_FIELD',
        attr2 TYPE scx_attrname VALUE '',
        attr3 TYPE scx_attrname VALUE '',
        attr4 TYPE scx_attrname VALUE '',
      END OF field_invalid.


    DATA: mv_field TYPE string READ-ONLY.


    METHODS: constructor
      IMPORTING textid   LIKE if_t100_message=>t100key OPTIONAL
                previous LIKE previous OPTIONAL
                iv_field TYPE string OPTIONAL.


ENDCLASS.




" Throw exception
RAISE EXCEPTION TYPE zcx_with_message
  EXPORTING
    textid   = zcx_with_message=>field_invalid
    iv_field = 'KUNNR'.




" Retrieve text
CATCH zcx_with_message INTO DATA(lx_error).
  " get_text() returns: "Field KUNNR contains invalid value"
  DATA(lv_msg) = lx_error->get_text( ).


  " Or as MESSAGE
  MESSAGE lx_error TYPE 'I'.

11. RESUMABLE Exceptions

CLASS zcx_resumable_error DEFINITION
  PUBLIC
  INHERITING FROM cx_static_check
  CREATE PUBLIC.


  PUBLIC SECTION.
    DATA: mv_value TYPE i READ-ONLY.


    METHODS: constructor
      IMPORTING iv_value TYPE i OPTIONAL
                previous LIKE previous OPTIONAL.
ENDCLASS.




METHOD process_values.
  LOOP AT lt_values INTO DATA(lv_value).
    IF lv_value < 0.
      " RESUMABLE: Can be continued with RESUME
      RAISE RESUMABLE EXCEPTION TYPE zcx_resumable_error
        EXPORTING iv_value = lv_value.
    ENDIF.


    " Further processing...
  ENDLOOP.
ENDMETHOD.




" Call with RESUME
TRY.
    process_values( ).


  CATCH BEFORE UNWIND zcx_resumable_error INTO DATA(lx_error).
    WRITE: / 'Warning: Negative value', lx_error->mv_value.
    RESUME.  " Continue after RAISE RESUMABLE
ENDTRY.

12. Best Practice: Exception Factory

CLASS zcx_factory DEFINITION.
  PUBLIC SECTION.
    CLASS-METHODS:
      not_found
        IMPORTING iv_entity TYPE string
                  iv_id     TYPE string
        RETURNING VALUE(ro_exception) TYPE REF TO zcx_not_found,


      validation_failed
        IMPORTING iv_field   TYPE string
                  iv_message TYPE string
        RETURNING VALUE(ro_exception) TYPE REF TO zcx_validation_error.
ENDCLASS.


CLASS zcx_factory IMPLEMENTATION.
  METHOD not_found.
    ro_exception = NEW #(
      iv_entity = iv_entity
      iv_id     = iv_id
    ).
  ENDMETHOD.


  METHOD validation_failed.
    ro_exception = NEW #(
      iv_field   = iv_field
      iv_message = iv_message
    ).
  ENDMETHOD.
ENDCLASS.




" Usage
RAISE EXCEPTION zcx_factory=>not_found(
  iv_entity = 'Customer'
  iv_id     = '12345'
).

Creating Exception Class in SE24

  1. SE24 → Create class (name starts with ZCX_ or YCX_)
  2. Superclass: CX_STATIC_CHECK (or other)
  3. Interfaces: Add IF_T100_MESSAGE
  4. Attributes: Define error data (e.g., MV_ORDER_ID)
  5. Texts: Link exception IDs with message class
  6. Constructor: Define parameters for attributes

Important Notes / Best Practice

  • CX_STATIC_CHECK for business exceptions (must be declared in RAISING).
  • Custom hierarchy for business domains (e.g., ZCX_ORDER_BASE).
  • IF_T100_MESSAGE for multi-language texts with message class.
  • PREVIOUS for exception chains (trace root cause).
  • READ-ONLY for exception attributes (immutability).
  • Catch specific exceptions first, then more general ones.
  • THROW in COND/SWITCH for inline exceptions.
  • RESUMABLE for warnings that can be skipped.
  • Exception texts in message class for translatability.
  • get_text() for formatted error message.