Exceptions are events in the execution of an ABAP program that interrupt the program when it is not possible for the program to continue in a meaningful way. Exception handling enables a reaction to these events.
Exception situations can be recognized either by the program or by the runtime environment. When an exception situation is recognized, either the ABAP program or the runtime environment raises an exception. Exceptions in the ABAP runtime environment are generally caused by error situations that cannot be predicted by the static program check.
Exceptions are either handleable or unhandleable.
- Handleable exceptions are class-based. They are predefined
in the system, or custom exceptions can be defined. They are raised either by the ABAP runtime environment
or by the statement
RAISE EXCEPTIONin a program and can be handled by
TRY - CATCH - ENDTRY. As well as these, non-class-based exceptions and (obsolete) catchable runtime errors also exist.
- Unhandleable exceptions are raised only be the ABAP runtime environment. They are a response to error situations that cannot generally be handled meaningfully in a program.