hibernate报类型转换异常

java.lang.NullPointerException

at org.hibernate.type.LongType.next(LongType.java:76)

at org.hibernate.type.LongType.next(LongType.java:40)

at org.hibernate.engine.Versioning.increment(Versioning.java:131)

atorg.hibernate.event.def.DefaultFlushEntityEventListener.getNextVersion(DefaultFlushEntityEventListener.java:406)

at org.hibernate.event.def.DefaultFlushEntityEventListener.scheduleUpdate(DefaultFlushEntityEventListener.java:296) 

at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:155)

at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:219)

at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)

at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)

at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)

at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)

at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)

at org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:558)

at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:662)

at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:632)

at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:319)

at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:116)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)

at com.saicmotor.framework.exception.MethodExceptionAdvice.invoke(MethodExceptionAdvice.java:20)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)

at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)

at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)

at com.sun.proxy.$Proxy382.doSaveECUList(Unknown Source)

at com.saicmotor.gbom.webapp.action.tggb.GbECUChangeAction.executeEcu(GbECUChangeAction.java:182)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:606)

at org.apache.commons.beanutils.MethodUtils.invokeMethod(MethodUtils.java:216)

at com.saicmotor.framework.webapp.action.BaseDataGridAction.dynamicInvoke(BaseDataGridAction.java:1021)

at sun.reflect.GeneratedMethodAccessor1125.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

    报数据类型错误，说明是转换类型的时候错误。要么存在垃圾数据，要么代码中没有准换类型，或者是数据库中有字段类型不匹配。但是无法定位到是哪里出错了，通过跟踪代码发现，是标记版本的地方出现了类型错误。在hibernate中是体重没有标记字段是version的字段，最终找到有使用@version标注的字段。

    Bug：数据库字段定义了一个长整形字段，但是默认填充为null。

    Bug原因：查询得到的数据包含此字段，但是对数据进行修改时，由于null和正行之间无法转换所以报错类型转换错误。

解决方案：修改数据库默认值为0