Class-based exceptions are implemented as instances of exception classes. Exception classes are either predefined globally in the system or can be defined by the user (globally or locally). Class-based exceptions are raised either by the ABAP runtime environment or by a program.
- Exception situations detected by the system, and whose causes can be handled in the program, raise predefined class-based exceptions.
- The exceptions of all exception classes visible in a program can be raised as program-driven exceptions as follows:.
- Using the statement
- Class-based exceptions can be declared in the interface of
procedures. This is done using the addition
RAISINGof the statements
FORM. In Class Builder and Function Builder, this is done by selecting exception classes when defining exceptions in the interface. The declared exceptions can occur at the call position of a procedure if the exception is not handled in the procedure.
When an exception is raised, an exception object can be created, whose attributes contain information
about the error situation. A class-based exception can be handled in a
TRY control structure. The
TRY block defines a protected area
whose exceptions can be handled in subsequent
CATCH blocks. The statement
RETRY enables a full
block to be retried after an exception. Because all exception classes are subclasses of common superclasses, the associated exceptions can be handled at the same time by handling the respective superclass. The system
propagates the exception object or the class-based exception until the exception is handled or an interface is violated.
There are two different exception handling cases:
A prerequisite for the second case are
resumable exceptions. These exceptions must be raised using the addition
of the statement
and declared using the addition
RESUMABLE in the interface of the procedures
from which they were propagated. The statement
RESUME is used to resume the program.