异常描述：在执行以下方法出现此异常：
注：类Role 与类Function 呈多对多关联，这里是添加一个role并添加三个function
@Test//fail
public void add(){
Role r = new Role();
r.setRname("Java项目经理");
Function f = functionService.findById(98);
Function f1 = functionService.findById(99);
Function f2 = functionService.findById(100);
r.getFunctions().add(f);
r.getFunctions().add(f1);
r.getFunctions().add(f2);
roleService.saveOrUpdate(r);
}
具体异常信息：
org.springframework.dao.DuplicateKeyException: a different object with the same identifier value was already associated with the session: [com.chen.vo.Function#99]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.chen.vo.Function#99]
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:662)
at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411)
at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374)
at org.springframework.orm.hibernate3.HibernateTemplate.saveOrUpdate(HibernateTemplate.java:737)
at com.chen.dao.RoleDaoImpl.saveOrUpdate(RoleDaoImpl.java:52)
at com.chen.service.RoleService.saveOrUpdate(RoleService.java:38)
at com.chen.service.RoleService$$FastClassByCGLIB$$be28c933.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:713)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:646)
at com.chen.service.RoleService$$EnhancerByCGLIB$$3b898394.saveOrUpdate(<generated>)
at com.chen.test.RoleTest.add(RoleTest.java:37)
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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.chen.vo.Function#99]
at org.hibernate.engine.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:613)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:307)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:246)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:112)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:527)
at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:241)
at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:292)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:240)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:193)
at org.hibernate.engine.Cascade.cascadeCollectionElements(Cascade.java:320)
at org.hibernate.engine.Cascade.cascadeCollection(Cascade.java:266)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:243)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:193)
at org.hibernate.engine.Cascade.cascade(Cascade.java:154)
at org.hibernate.engine.Cascade.cascade(Cascade.java:121)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.cascadeOnUpdate(DefaultSaveOrUpdateEventListener.java:380)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:352)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:246)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:112)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:527)
at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:241)
at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:292)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:240)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:193)
at org.hibernate.engine.Cascade.cascadeCollectionElements(Cascade.java:320)
at org.hibernate.engine.Cascade.cascadeCollection(Cascade.java:266)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:243)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:193)
at org.hibernate.engine.Cascade.cascade(Cascade.java:154)
at org.hibernate.event.def.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:479)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:357)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:204)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:144)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:117)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:527)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:523)
at org.springframework.orm.hibernate3.HibernateTemplate$16.doInHibernate(HibernateTemplate.java:740)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
... 45 more
分析：根据异常的字面信息及网上提示总结原因是在com.chen.vo.Function中定义了相同的Object，类Function代码如下：
public class Function implements Serializable{
private int fid;
private String fname;
private String namespace;
private String actioname;
private String method;
// private int parentid;
private Function parent;
private Set<Function> childs = new HashSet<Function>();
private Set<Role> roles = new HashSet<Role>();
//...
}
类Role的代码：
public class Role {
private int rid;
private String rname;//角色名
private Set<Empl> empls = new HashSet<Empl>();
private Set<Function> functions = new HashSet<Function>();
//..
}
从以上代码可看出在类Function与类Role中均有Set<Function>的定义，因此在添加role级联添加function时出现此异常。
解决方法：
采用session.merge (object o)方法，这里是hibernateTemplate.merge(object o);
代码：
@Test//success
public void add2(){
Role r = new Role();
r.setRname("Java项目经理");
Function f = functionService.findById(98);
Function f1 = functionService.findById(99);
Function f2 = functionService.findById(100);
r.getFunctions().add(f);
r.getFunctions().add(f1);
r.getFunctions().add(f2);
hibernateTemplate.merge(r);
}
具体原理现在也不多去分析了，详情参见：
http://lcy0202.iteye.com/blog/1453868