Aug 17, 2010 11:23:26 PM dustin.examples.MapContainsGet generateStatesMapSEVERE: java.util.concurrent.ConcurrentHashMap does not allow for null values – java.lang ...

JPA and Hibernate enum mapping. The Java enum, introduced in Java 5, will map to the underlying database without any intervention. The JPA framework, be it Hibernate or Toplink or DataNucleus, will ...