title: How to identify EJB entity property changes in @PreUpdate?
body: <p>when persisting (updating) an entity you would call <strong>EntityManager.persist(entity)</strong> passing the complete entity. It is possible to intercept with <strong>@PreUpdate</strong>.</p>
  
  <p>Does anyone have a recipe how to <em>identify which properties have changed</em> in this interceptor method ? Somehow comparing the old and the new entity ? Even better to implement a generic method instead of comparing field by field for each class.</p>
  
  <p>Thanks for any input !</p>
  
  <p>Sven</p>