Customization points during publish channel processing
Publish channels process outbound integration messages that do not require a response. The Java™ processing class that is associated with a publish channel includes several hooks where you can insert code to provide custom logic.
The illustration shows the customization points during outbound processing of integration messages by using publish channels.

- External exit class
- User exit class that runs before the external exit class
- User exit class that runs after the external exit class
- Event filter class
When you configure an external exit or user exit script for a publish channel, a predefined Java class is inserted on the channel that is used to run the script. The predefined classes are the com.ibm.tivoli.maximo.script.ScriptExternalExit class and the com.ibm.tivoli.maximo.script.ScriptUserExit class. You cannot implement a script and a Java class at the same processing point. If you attempt to create a script on a processing point where a Java class is configured, you cannot save the script.