I have a blob field that don't want updated when I do a save on other fields in the table. Hibernate seems to be doing an areEqual check despite the fact that I've designated the field as updatable=false. Because the field is lazy loaded it's null and I get a ClassCastException when it does the areEqual check on save. Why is it doing a compare on that field when it's not updatable?

So my field is designated as such:

@Basic(fetch = FetchType.LAZY)
@Column(
insertable = true,
updatable = false,
name = "documentData"
)
@Lob private Blob documentData;
On org.springframework.data.repository.CrudRepository.save() I get the following error:

java.lang.ClassCastException: org.hibernate.bytecode.instrumentation.spi.LazyPropertyInitializer$1 cannot be cast to java.sql.Blob
at org.hibernate.type.descriptor.java.BlobTypeDescriptor.areEqual(BlobTypeDescriptor.java:45)
at org.hibernate.type.AbstractStandardBasicType.isEqual(AbstractStandardBasicType.java:196)
at org.hibernate.ejb.event.EJB3FlushEntityEventListener.copyState(EJB3FlushEntityEventListener.java:79)
at org.hibernate.ejb.event.EJB3FlushEntityEventListener.invokeInterceptor(EJB3FlushEntityEventListener.java:66)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.handleInterception(DefaultFlushEntityEventListener.java:334)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.scheduleUpdate(DefaultFlushEntityEventListener.java:285)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:164)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:225)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1214)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:403)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:175)
at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:75)
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:512)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:394)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.data.jpa.repository.support.LockModeRepositoryPostProcessor$LockModePopulatingMethodIntercceptor.invoke(LockModeRepositoryPostProcessor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy216.save(Unknown Source)