我在尝试更新记录时遇到了 NPE。实体类使用@Version 注释，并且版本列不为空，具有默认（1）值。表中没有版本字段为空值的记录，但我仍然得到一个 NPE。以下是错误详情：
Oct 23, 2013 9:00:51 PM com.sun.xml.ws.server.sei.EndpointMethodHandler invoke
SEVERE: null
java.lang.NullPointerException
at org.hibernate.type.IntegerType.next(IntegerType.java:82)
at org.hibernate.type.IntegerType.next(IntegerType.java:39)
at org.hibernate.engine.Versioning.increment(Versioning.java:131)
at org.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.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:58)
at org.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1185)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1261)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.springframework.orm.hibernate3.HibernateTemplate$31.doInHibernate(HibernateTemplate.java:947)
at org.springframework.orm.hibernate3.HibernateTemplate$31.doInHibernate(HibernateTemplate.java:1)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374)
at org.springframework.orm.hibernate3.HibernateTemplate.findByNamedParam(HibernateTemplate.java:938)
at org.springframework.orm.hibernate3.HibernateTemplate.findByNamedParam(HibernateTemplate.java:929)
at server.dao.PatientDAOImpl.updatePatient(PatientDAOImpl.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy30.updatePatient(Unknown Source)
at server.service.PersistenceServiceImpl.updatePatient(PersistenceServiceImpl.java:125)
at server.service.ServiceEndpoint.updatePatient(ServiceEndpoint.java:170)
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:601)
at com.sun.xml.ws.api.server.InstanceResolver$1.invoke(InstanceResolver.java:246)
at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:146)
at com.sun.xml.ws.server.sei.EndpointMethodHandler.invoke(EndpointMethodHandler.java:257)
at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:95)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:629)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:588)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:573)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:470)
at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:295)
at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:519)
at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:288)
at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:143)
at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doGet(WSServletDelegate.java:155)
at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doPost(WSServletDelegate.java:189)
at com.sun.xml.ws.transport.http.servlet.WSServlet.doPost(WSServlet.java:76)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
注意：我通过添加版本列更新了旧数据库，因此必须获得休眠的乐观锁定功能。
数据库更改：
ALTER TABLE Patient ADD VERSION INT NOT NULL DEFAULT (1)
GO
实体类：
@Version
@Column(name = "VERSION")
private Integer version;
代码：
@SuppressWarnings("unchecked")
@Transactional(readOnly = false, propagation = Propagation.REQUIRED)
public Long updatePatient(Patient patient, String action) {
Long patientId = patient.getId();
long caseId = 0l;
long siteId = 0l;
long clientId = 0l;
if (patientId == null) { // new Patient
getHibernateTemplate().save(patient);
} else if(action!=null && action.equals("UPDATE")){
getHibernateTemplate().update(patient);
List<Case> caseList = getHibernateTemplate().findByNamedParam(
"select c from Case c where c.patient.id=:patientId and deleted=0", "patientId",patientId); // Line 158 - Error is raised here
if(caseList!=null && caseList.size()>0){
caseId = caseList.get(0).getId();
siteId = caseList.get(0).getSiteId();
}
List<Site> site = getHibernateTemplate().findByNamedParam(
"from Site where id=:siteId", "siteId",siteId);
if(site!=null && site.size()>0){
clientId = site.get(0).getClientId();
}
}else if(action!=null && action.equals("DELETE")){
getHibernateTemplate().delete(patient);
}
return patientId;
}