Defining the Failure Message
You can use Groovy to create the error message to be displayed. In the example in the slide, two expressions are used to display the attribute and its value in the error message.
When you enter a word surrounded by braces, JDeveloper interprets this as a message token and automatically adds it to the Token Message Expressions section. You can then provide a value for each message token that displays in the error message at run time when validation fails.
The message token expressions shown in the example use Groovy syntax. Although these are very simple expressions, it is important to understand that developers can leverage the full power of Groovy when necessary.
Failure handling can also use error messages from a resource bundle.