If an application needs to implement customized event handling, it must implement this interface and then register it with either the Unmarshaller, the Validator, or the Marshaller. The JAXB Provider will then report validation errors and warnings encountered during the unmarshal, marshal, and validate operations to these event handlers.

If the handleEvent method throws an unchecked runtime exception, the JAXB Provider must treat that as if the method returned false, effectively terminating whatever operation was in progress at the time (unmarshal, validate, or marshal).

Modifying the Java content tree within your event handler is undefined by the specification and may result in unexpected behaviour.

Failing to return false from the handleEvent method after encountering a fatal error is undefined by the specification and may result in unexpected behavior.

Default Event Handler

See: Validator javadocs