How to use Class Exeptions in ABAP

ABAP Class Exception Example..abap

* Prerequirements:
*
*  1. Create an Exception Class /{PACKAGE}/CX_{NAME} in the working package.
*  2. Open the Exception Class and add Interface: "IF_T100_MESSAGE" to it.
*  3. Create a 'Nachrichtenklasse' with the name /{Package}/(...)_{NAME}_NK
*
*Then:
*
*  1. Open the working Class and select a method to which to add an exception.
*  2. Open the Parameter Section for the Method then choose the exception section and add the exception name /{PACKAGE}/CX_{NAME} to the Method! 
*  3. Open the methods program code and add this data dekleration (structure for the output).
*  4. Fill the structure with information to be passed to the user.
*  5. Raise the exception in the method after an error or errouros state was entered using the syntax RAISE EXCEPTION TYPE /{PACKAGE}/CX_{NAME} EXPORTING ________ .

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* EXAMPLE: CLASS/METHOD
********************************************************

DATA: ls_t100_key type scx_t100key.

*... some code to be executed ... 

IF SY-SUBRC <> 0. "error
  ls_t100_key-msgid = '/PACKACKGE/test_messegeclass'.
  ls_t100_key-msgno = 000. " TEXT TO BE PRINTED FROM MESSEGE CLASS! (USE & FOR ATTRIBUTES) 
  RAISE EXCEPTION TYPE /package/cx_text_exception_class EXPORTING textid = ls_t100_key.
ENDIF.

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* EXAMPLE: Optional Implement this as Method in the Class:
********************************************************
  class-methods THROW_EXCEPTION
    importing
      !IV_MSG_ID type SYMSGID optional
      !IV_MSG_NUMBER type SYMSGNO
      !IV_ATTRIBUT1 type SCX_ATTRNAME optional
      !IV_ATTRIBUT2 type SCX_ATTRNAME optional
      !IV_ATTRIBUT3 type SCX_ATTRNAME optional
      !IV_ATTRIBUT4 type SCX_ATTRNAME optional
    raising
      /PSI/CX_DYNAMIC_ALV .


method THROW_EXCEPTION.
    DATA: ls_t100_key type scx_t100key.
    if iv_msg_id is initial.
    ls_t100_key-msgid = 'nachrichtenklasse'.
    else.
    ls_t100_key-msgid = iv_msg_id.
    endif.
    ls_t100_key-msgno = iv_msg_number.
    ls_t100_key-attr1 = iv_attribut1.
    ls_t100_key-attr2 = iv_attribut2.
    ls_t100_key-attr3 = iv_attribut3.
    ls_t100_key-attr4 = iv_attribut4.
    RAISE EXCEPTION TYPE /package/cx_name EXPORTING textid = ls_t100_key.
endmethod.


*  6. Declare the exception as reference in the program code.
*  7. Finally wrap the messege call with a TRY. CATCH. ENDTRY. block. 

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* EXAMPLE: PROGRAM
********************************************************

data: lx_exception type ref to /package/cx_text_exception_class.

Try.
  Class->Method()
CATCH /package/cx_text_exception_class into lx_exception.
  MESSAGE lx_exception TYPE 'I' DISPLAY LIKE 'E'.
  LEAVE LIST-PROCESSING.
Endtry.