IBM BPM, V8.0.1, All platforms > Get started with IBM BPM > Key concepts > Business objects > Business object parsing mode
Application migration and development considerations
If you are configuring an application that was originally developed using eager parsing mode to now use lazy parsing mode, or if you are planning to switch an application between lazy and eager parsing mode, be aware of the differences between modes and the considerations when switching modes.
Error handling
If the XML byte stream being parsed is ill-formed, parsing exceptions occur.
- In eager XML parsing mode, those exceptions occur as soon as the business object is parsed from the inbound XML stream.
- If lazy XML parsing mode is configured, the parsing exceptions occur latently when the business object properties are accessed and the portion of the XML that is ill-formed is parsed.
To deal with ill-formed XML, select one of the following options:
- Deploy an enterprise service bus on the edges to validate inbound XML
- Author lazy error-detection logic at the point where business object properties are accessed
Exception stacks and messages
Because the eager and lazy XML parsing modes have different underlying implementations, stack traces thrown by the business object programming interfaces and services have the same exception class name, but they might not contain the same exception message or wrapped set of implementation-specific exception classes.
XML serialization format
The lazy XML parsing mode provides a performance optimization that attempts to copy unmodified XML from the inbound byte stream to the outbound byte stream upon serialization. The result is increased performance, but the serialization format of the outbound XML byte stream might be different if the entire business object was updated in lazy XML parsing mode or if it was running in eager XML parsing mode.
Although the XML serialization format might not be precisely syntactically equivalent, the semantic value provided by the business object is equivalent independent of the parsing modes, and XML can be safely passed between applications running in different parsing modes with semantic equivalence.
Business object instance validator
The lazy XML parsing business object mode instance validator provides a higher fidelity validation of business objects, particularly facet validation of property values. Because of these improvements, the lazy parsing mode instance validator catches additional issues that are not caught in eager parsing mode and provides more detailed error messages.
Version 602 XML Maps
Mediation flows originally developed before WebSphere Integration Developer Version 6.1 might contain Mapping primitives that use a map or stylesheet that cannot run directly in lazy XML parsing mode. When an application is migrated for use in lazy XML parsing mode, map files associated with Mapping primitives can be automatically updated by the migration wizard to run in the new mode. However, if a Mapping primitive refers directly to a stylesheet that has been edited manually, the stylesheet is not migrated and cannot run in lazy XML parsing mode.
Private unpublished APIs
If an application is taking advantage of unpublished, private, implementation-specific business object programming interfaces, the application is likely to fail compilation when the parsing mode is switched. In eager parsing mode, these private interfaces are typically business object implementation classes defined by the Eclipse Modeling Framework (EMF).
In all cases, it is strongly recommend that private APIs be removed from the application.
Service Message Object EMF APIs
A mediation component in IBM Integration Designer provides the ability to manipulate message content using the Java™ classes and interfaces provided in the com.ibm.websphere.sibx.smobo package. In lazy XML parsing mode, the Java interfaces in the com.ibm.websphere.sibx.smobo package can still be used, but methods that refer directly to Eclipse Modeling Framework (EMF) classes and interfaces or that are inherited from EMF interfaces are likely to fail.
The ServiceMessageObject and its contents cannot be cast to EMF objects in lazy XML parsing mode.
BOMode service
The BOMode service is used to determine whether the currently executing XML parsing mode is eager or lazy.
Migration
All applications before version 7.0.0.0 are running in eager XML parsing mode. When they are runtime migrated using the BPM runtime migration tools, they continue to run in eager XML parsing mode.
To enable an application earlier than version 7.0.0.0 to be configured to use the lazy XML parsing mode, you first use Integration Designer to migrate the artifacts of the application. After migration, you then configure the application to use lazy XML parsing.
See Migrating source artifacts for information on migrating artifacts in Integration Designer, and see Configure the business object parsing mode of modules and libraries for information on setting the parsing mode.