Application design considerations for exceptions and faults

In order to create a comprehensive error handling strategy, solution architects need to understand howIBM Workflow Server represents declared and undeclared exceptions.

The SCA programming model provides two types of exceptions:

• Service Business Exceptions

  Service Business Exceptions are checked exceptions declared in a business method's function signature (WSDL faults or Java™ throws). Service Business Exceptions identify error conditions that are anticipated by the application or service. These exceptions are sometimes referred to as "checked exceptions"

  An example is an InvalidSymbolException for a stock quote service. Such exceptions are wrapped by ServiceBusinessException and passed back to the client.

• Service Runtime Exceptions

  Also known as "system exceptions" service runtime exceptions are not declared in the method signature. In general, they represent error conditions that are not anticipated by the application, such as a NullPointerException in a Java Component.

  These exceptions are wrapped by ServiceRuntimeException and passed back to the client, which can interrogate the ServiceRuntimeException to determine the cause.

  Note: When working at the SCA level these exceptions are sometimes referred to as faults. However, when using Java code they are usually referred to as exceptions.

  When a ServiceRuntimeException is thrown from a component, the current transaction will be rolled back.