我遇到了一个由一堆线程同时访问的方法的问题。场景是线程A遍历列表，创建并保存域对象。线程B在线程A仍在迭代时调用相同的方法，尝试访问线程A创建的域对象，并抛出StaleStateException。
举例说明：
def populateStudents(listOfStudents) {
listOfStudents.each { Student student ->
def schoolName = student.schoolName
def school = School.findByName(schoolName) ?: new School(name: schoolName).save(flush:true)
student.addToSchools(school)
// So Thread A creates a new School domain object and continues to iterate.
// Thread B comes along and finds the domain created by Thread A.
// However, it appears that the StaleStateException is thrown when Thread B tries to addToSchools
}
}
这是堆栈：
org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.app.School#60]
at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:1792)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2435)
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2335)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2635)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:115)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
at org.codehaus.groovy.grails.orm.hibernate.events.PatchedDefaultFlushEventListener.performExecutions(PatchedDefaultFlushEventListener.java:46)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
at org.springframework.orm.hibernate3.HibernateTemplate$28.doInHibernate(HibernateTemplate.java:883)
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.flush(HibernateTemplate.java:881)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.MergePersistentMethod$1.doInHibernate(MergePersistentMethod.java:60)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:339)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.MergePersistentMethod.performSave(MergePersistentMethod.java:54)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.AbstractSavePersistentMethod.doInvokeInternal(AbstractSavePersistentMethod.java:179)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.AbstractDynamicPersistentMethod.invoke(AbstractDynamicPersistentMethod.java:59)
at sun.reflect.GeneratedMethodAccessor23965.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:188)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:52)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:132)
at org.codehaus.groovy.grails.plugins.orm.hibernate.HibernatePluginSupport$_addBasicPersistenceMethods_closure73.doCall(HibernatePluginSupport.groovy:814)
at sun.reflect.GeneratedMethodAccessor845.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaMethod.invoke(ClosureMetaMethod.java:80)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoMetaMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:307)
at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.call(PogoMetaMethodSite.java:63)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:124)
at com.app.TransactionService$_populateStudents_closure3.doCall(TransactionService.groovy:96)
at sun.reflect.GeneratedMethodAccessor24059.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1058)
at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1070)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:886)
at groovy.lang.Closure.call(Closure.java:282)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.eachWithIndex(DefaultGroovyMethods.java:1213)
at org.codehaus.groovy.runtime.dgm$150.invoke(Unknown Source)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:270)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:52)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:124)
at com.app.TransactionService.populateStudents(TransactionService.groovy:49)
at com.app.TransactionService$$FastClassByCGLIB$$1b289e99.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:688)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:621)
at com.app.TransactionService$$EnhancerByCGLIB$$8986440c.populateStudents(<generated>)
INFO UpdateController - Object of class [com.app.School] with identifier [60]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.app.School#60]
任何想法
答案 0 :(得分：4)
您可以使用pessimistic locking：
解决此问题def school = School.findByName(schoolName, [lock: true]) ?: new School(name: schoolName).save(flush:true)