我有一个j2ee Web应用程序，我正在使用hibernate和struts2框架。 该项目在本地服务器上运行正常，但是当我在Web上传应用程序并且更多用户同时访问它时，会抛出此错误：
Illegal attempt to associate a collection with two open sessions
突然整个hibernate系统崩溃，我无法执行任何查询。 这是stacktrace：
'org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
at org.hibernate.collection.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:432)
at org.hibernate.event.def.WrapVisitor.processCollection(WrapVisitor.java:67)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:124)
at org.hibernate.event.def.WrapVisitor.processValue(WrapVisitor.java:121)
at org.hibernate.event.def.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:78)
at org.hibernate.event.def.DefaultFlushEntityEventListener.wrapCollections(DefaultFlushEntityEventListener.java:218)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:152)
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:1175)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1251)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.hibernate.impl.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:859)
at com.hposg.login.LoginFactory.doLogin(LoginFactory.java:31)
at com.hposg.controller.struts.LoginAction.execute(LoginAction.java:50)
at sun.reflect.GeneratedMethodAccessor489.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:636)
这是引起这个问题的代码：
public static Player doLogin(String ID, String pass) throws LoginException , BanedUser{
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
Player player = (Player) session.createQuery(
"from Player as player where player.loginName = " + "'" + ID
+ "' and player.passWord ='" + pass + "'")
.uniqueResult();
if (player == null)
throw new LoginException();
else if (!player.getIsActive())
throw new BanedUser();
UserSession.getInstance();
UserSession.addPlayer(player);
session.beginTransaction().commit();
return player;
}
错误不定期发生（每周一次，每隔一天等），任何可能导致此问题的想法？
这是我的hibernate.cfg.xml：
<?xml version='1.0' encoding='utf-8'?>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">
jdbc:mysql://localhost/hposg?characterEncoding=UTF-8
</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property>
<!-- Mapping files -->
<mapping resource="com/hposg/hibernate/resources/Player.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Game.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Portfolio.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Purchase.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Sale.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Message.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Admin.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/News.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Invitation.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/CustomGameCreationRequest.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Alert.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/AlertLimits.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/StockIndex.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/HPOSG.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Tradeable.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/GlobalGameConfig.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/Announcement.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/AdviserMsg.hbm.xml"/>
<mapping resource="com/hposg/hibernate/resources/SystemConfiguration.hbm.xml"/>
</session-factory>
以下是我的LoginAction作为我使用hibernate的策略的一个例子：
try {
Player player = LoginFactory.doLogin(username.toLowerCase(),
password);
Session lSession = HibernateUtil.getSessionFactory()
.getCurrentSession();
lSession.beginTransaction();
lSession.lock(player, LockMode.NONE);
player.getInbox().size();
Collection<Message> unreadMsgs = lSession
.createQuery(
"FROM Message message WHERE Respondent.id='"
+ player.getId()
+ "' AND message.isRead=false").list();
lSession.getTransaction().commit();
UserSession.getInstance().addPlayer(player);
Map session = (Map) ActionContext.getContext().get("session");
session.put("UID", username.toLowerCase());
session.put("TYPE", "PLAYER");
session
.put("NAME", player.getName() + " "
+ player.getFamily());
session.put("UNREADMSGS", unreadMsgs.size());
session.put("LAST_VIEWED_GAME_ID", 0);
return SUCCESS;
} catch (LoginException a) {
addActionError(a.getMessage());
return "error";
} catch (Exception a) {
addActionError(e.getMessage());
return "error";
}
答案 0 :(得分：2)
您的代码显示您创建了2个交易....试试这个： -
public static Player doLogin(String ID, String pass) throws LoginException , BanedUser{
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
Transaction tx = session.beginTransaction();
...
tx.commit();
return player;
}
答案 1 :(得分：0)
请确认您使用XWork操作类作为Spring bean？ 如果是这种情况，可能你忘了遵循Struts2 / Spring中的指令，当你有动作bean作为Spring bean时（在Dependency Injection控制器中）... 你需要将bean声明为非单例！ 在声明中确保您有 singleton =“false”属性。
如果你忘记这样做会怎么样？一个用户访问相同的操作，一切正常。超过1个用户访问您的bean，您在单例bean中有竞争条件。我怀疑你的应用程序确实发生了什么。
答案 2 :(得分：0)
显然使用合并可能会解决问题
myInstance = (myInstanceClass) Session.merge(myInstance);