EclipseLink adding a Converter causes ValidationException intermittently

Question

I am building a new application using EclipseLink for the first time.

Everything was going okay until I added an entity that uses JSR310 Instant for a timestamp column.

So I created a converter class and mapped it to the the associated field like so:

@Convert(converter = JSR310InstantTypeConverter.class)
private Instant   pwdChangeCodeExpiresOn = null;

However since I added that converter the application has started throwing the following exception:

SEVERE: Servlet.service() for servlet [APIJerseyServlet] in context with path [/Sclera] threw exception [org.glassfish.jersey.server.ContainerException: java.lang.ExceptionInInitializerError] with root cause
Local Exception Stack: 
Exception [EclipseLink-7351] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The converter class [com.sclera.utils.JSR310InstantTypeConverter] specified on the mapping attribute [pwdChangeCodeExpiresOn] from the class [com.sclera.entity.Admin] was not found. Please ensure the converter class name is correct and exists with the persistence unit definition.
    at org.eclipse.persistence.exceptions.ValidationException.converterClassNotFound(ValidationException.java:2317)
    at org.eclipse.persistence.internal.jpa.metadata.converters.ConvertMetadata.process(ConvertMetadata.java:248)

This will start happening after a code change (when Eclipse restarts the server). I have to stop and start (and/or restart) the server manually a few times until it finally starts working again. Then it will work fine until a code change or two later when it will start throwing the exception again.

This is an enormous pain. Anyone know the cause and how to fix it?

Answer 1

Okay solution found. Adding the converter class to the persistence.xml file - as suggested by the error message - seems to have resolved the problem.

<persistence-unit name="example" transaction-type="RESOURCE_LOCAL">
  ....
  <class>com.example.utils.JSR310InstantTypeConverter</class>
  ...
</persistence-unit>

I should have tried that earlier. The fact that is working some of the time without this made me think it wouldn't make a difference.