Firebird + JayBird + Hibernate + Tomcat

Boa tarde, estou enfrentando o seguinte problema:

Quando eu inicio o tomcat no servidor a conecção com o banco de dados funciona normalmente, mas se eu ficar algum tempo (umas 2 horas) sem realizar alguma transação com o firebird ele começa a dar erro: org.hibernate.exception.GenericJDBCException: could not execute query.
Se eu reiniciar o tomcat ele volta a funcionar normalmente. O que pode estar acontecendo? E qual seria a solução?

Obrigado!

segue abaixo o erro e as configurações:


HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

br.com.caelum.vraptor.InterceptionException: an exception was raised while executing resource method
	br.com.caelum.vraptor.interceptor.ExecuteMethodInterceptor.intercept(ExecuteMethodInterceptor.java:86)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ParametersInstantiatorInterceptor.intercept(ParametersInstantiatorInterceptor.java:77)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InstantiateInterceptor.intercept(InstantiateInterceptor.java:42)
	br.com.caelum.vraptor.core.InstantiatedInterceptorHandler.execute(InstantiatedInterceptorHandler.java:47)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InterceptorListPriorToExecutionExtractor.intercept(InterceptorListPriorToExecutionExtractor.java:46)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.FlashInterceptor.intercept(FlashInterceptor.java:80)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ResourceLookupInterceptor.intercept(ResourceLookupInterceptor.java:67)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.DefaultRequestExecution.execute(DefaultRequestExecution.java:70)
	br.com.caelum.vraptor.VRaptor$1.insideRequest(VRaptor.java:92)
	br.com.caelum.vraptor.ioc.spring.SpringProvider.provideForRequest(SpringProvider.java:56)
	br.com.caelum.vraptor.VRaptor.doFilter(VRaptor.java:89)

root cause

org.hibernate.exception.GenericJDBCException: could not execute query
	org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)
	org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)
	org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
	org.hibernate.loader.Loader.doList(Loader.java:2231)
	org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
	org.hibernate.loader.Loader.list(Loader.java:2120)
	org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
	org.hibernate.impl.SessionImpl.list(SessionImpl.java:1596)
	org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
	org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:328)
	br.com.cencob.dao.DevedorDao.busca(DevedorDao.java:35)
	br.com.cencob.controller.BoletosController.mostraBusca(BoletosController.java:48)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	br.com.caelum.vraptor.interceptor.ExecuteMethodInterceptor.intercept(ExecuteMethodInterceptor.java:57)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ParametersInstantiatorInterceptor.intercept(ParametersInstantiatorInterceptor.java:77)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InstantiateInterceptor.intercept(InstantiateInterceptor.java:42)
	br.com.caelum.vraptor.core.InstantiatedInterceptorHandler.execute(InstantiatedInterceptorHandler.java:47)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InterceptorListPriorToExecutionExtractor.intercept(InterceptorListPriorToExecutionExtractor.java:46)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.FlashInterceptor.intercept(FlashInterceptor.java:80)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ResourceLookupInterceptor.intercept(ResourceLookupInterceptor.java:67)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.DefaultRequestExecution.execute(DefaultRequestExecution.java:70)
	br.com.caelum.vraptor.VRaptor$1.insideRequest(VRaptor.java:92)
	br.com.caelum.vraptor.ioc.spring.SpringProvider.provideForRequest(SpringProvider.java:56)
	br.com.caelum.vraptor.VRaptor.doFilter(VRaptor.java:89)

root cause

org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544726. Error reading data from the connection.
null
Reason: Error reading data from the connection.
null
	org.firebirdsql.jdbc.InternalTransactionCoordinator$AutoCommitCoordinator.ensureTransaction(InternalTransactionCoordinator.java:224)
	org.firebirdsql.jdbc.InternalTransactionCoordinator$AutoCommitCoordinator.executionStarted(InternalTransactionCoordinator.java:213)
	org.firebirdsql.jdbc.InternalTransactionCoordinator.executionStarted(InternalTransactionCoordinator.java:38)
	org.firebirdsql.jdbc.AbstractStatement.notifyStatementStarted(AbstractStatement.java:235)
	org.firebirdsql.jdbc.AbstractStatement.notifyStatementStarted(AbstractStatement.java:226)
	org.firebirdsql.jdbc.AbstractPreparedStatement.<init>(AbstractPreparedStatement.java:121)
	org.firebirdsql.jdbc.FBPreparedStatement.<init>(FBPreparedStatement.java:41)
	sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	org.firebirdsql.jdbc.FBStatementFactory.createPreparedStatement(FBStatementFactory.java:90)
	org.firebirdsql.jdbc.AbstractConnection.prepareStatement(AbstractConnection.java:869)
	org.firebirdsql.jdbc.AbstractConnection.prepareStatement(AbstractConnection.java:824)
	org.firebirdsql.jdbc.AbstractConnection.prepareStatement(AbstractConnection.java:817)
	org.firebirdsql.jdbc.AbstractConnection.prepareStatement(AbstractConnection.java:293)
	org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:534)
	org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:452)
	org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
	org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
	org.hibernate.loader.Loader.doQuery(Loader.java:696)
	org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
	org.hibernate.loader.Loader.doList(Loader.java:2228)
	org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
	org.hibernate.loader.Loader.list(Loader.java:2120)
	org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
	org.hibernate.impl.SessionImpl.list(SessionImpl.java:1596)
	org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
	org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:328)
	br.com.cencob.dao.DevedorDao.busca(DevedorDao.java:35)
	br.com.cencob.controller.BoletosController.mostraBusca(BoletosController.java:48)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	br.com.caelum.vraptor.interceptor.ExecuteMethodInterceptor.intercept(ExecuteMethodInterceptor.java:57)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ParametersInstantiatorInterceptor.intercept(ParametersInstantiatorInterceptor.java:77)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InstantiateInterceptor.intercept(InstantiateInterceptor.java:42)
	br.com.caelum.vraptor.core.InstantiatedInterceptorHandler.execute(InstantiatedInterceptorHandler.java:47)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.InterceptorListPriorToExecutionExtractor.intercept(InterceptorListPriorToExecutionExtractor.java:46)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.FlashInterceptor.intercept(FlashInterceptor.java:80)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.interceptor.ResourceLookupInterceptor.intercept(ResourceLookupInterceptor.java:67)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
	br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:65)
	br.com.caelum.vraptor.core.DefaultRequestExecution.execute(DefaultRequestExecution.java:70)
	br.com.caelum.vraptor.VRaptor$1.insideRequest(VRaptor.java:92)
	br.com.caelum.vraptor.ioc.spring.SpringProvider.provideForRequest(SpringProvider.java:56)
	br.com.caelum.vraptor.VRaptor.doFilter(VRaptor.java:89)

hibernate.cfg.xml

<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
		<property name="hibernate.connection.username">user</property>
		<property name="hibernate.connection.password">123</property>
		<property name="hibernate.connection.url">jdbc:firebirdsql:111.11.1.111/1234:/home/banco/BANCO.FDB</property>
   		<property name="hibernate.dialect">org.hibernate.dialect.FirebirdDialect</property>  
		<property name="hibernate.connection.driver_class">org.firebirdsql.jdbc.FBDriver</property>
		<property name="hibernate.connection.autocommit">true</property>
		<property name="hibernate.hbm2ddl.auto">validade</property>
		<property name="hibernate.show_sql">true</property>
		<property name="hibernate.format_sql">true</property>

		<property name="hibernate.connection.pool_size">10</property>
		<property name="hibernate.current_session_context_class">thread</property>
		<property name="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
		
		<!-- configuration pool via c3p0-->
		<property name="hibernate.c3p0.min_size">5</property>
		<property name="hibernate.c3p0.max_size">10</property>
		<property name="hibernate.c3p0.timeout">180</property> 
		<property name="hibernate.c3p0.idle_test_period">100</property>		
		
	</session-factory>

</hibernate-configuration>