Hibernate exception java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.util.Date

Question

In our project we are facing exceptions with stack trace below. It happens sometimes during object merge (I can't reproduce it). I don't exactly know which object causes this error because lot of cascades. Environment does not matter, it occurs both in production and development environment.

We use Hibernate 4.2.5.Final, Spring 3.2.2.RELEASE, Java 7, Tomcat 7.

java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.util.Date
at org.hibernate.type.descriptor.java.JdbcTimestampTypeDescriptor.areEqual(JdbcTimestampTypeDescriptor.java:41)
at org.hibernate.type.AbstractStandardBasicType.isEqual(AbstractStandardBasicType.java:205)
at org.hibernate.type.AbstractStandardBasicType.isSame(AbstractStandardBasicType.java:195)
at org.hibernate.type.AbstractStandardBasicType.isDirty(AbstractStandardBasicType.java:231)
at org.hibernate.type.AbstractStandardBasicType.isDirty(AbstractStandardBasicType.java:227)
at org.hibernate.type.TypeHelper.findDirty(TypeHelper.java:294)
at org.hibernate.persister.entity.AbstractEntityPersister.findDirty(AbstractEntityPersister.java:4037)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.dirtyCheck(DefaultFlushEntityEventListener.java:527)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:234)
at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:163)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:228)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:100)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1234)
at org.springframework.orm.hibernate4.SpringSessionSynchronization.beforeCommit(SpringSessionSynchronization.java:91)
at org.springframework.transaction.support.TransactionSynchronizationUtils.triggerBeforeCommit(TransactionSynchronizationUtils.java:95)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.triggerBeforeCommit(AbstractPlatformTransactionManager.java:925)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:738)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:724)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:475)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:270)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at com.sun.proxy.$Proxy115.method(Unknown Source)
at com.some.package.OurClass.method(OurClass.java:114)

Edit: method "com.some.package.OurClass.method" just did Hibernate merge() operation.

Answer 1

I looked at it once more and I found the reason. We have field in our domain object with name "created" (of type date) and transient method isCreated. Methods look like this:

@Column(...)
public Date getCreated() {
    return created;
}

@Transient
public boolean isCreated() {
    return isStatus(StatusType.CREATED);
}

I solved it with renaming the method isCreated to isCreatedStatus().