Hi,

I have too much headache on MySql and Hibernate.

Since I replaced DB2 with MySql, EJB2.1 with Hibernate, I always have different errors from Hibernate.

some times the data in hibernate session is missing before close session.

Today I met another exception:
don't flush the Session after an exception occurs

javax.ejb.TransactionRolledbackLocalException: ; nested exception is: org.hibernate.AssertionFailure: null id in com.loyaltycentral.model.Merchant entry (don't flush the Session after an exception occurs)
at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:55)
at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:164)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:120)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:196)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:76)
at org.hibernate.event.def.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:35)
at org.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:969)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1114)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
at com.loyaltycentral.ejb.entity.service.ClientManagementEJBBean.getMerchantLocationTerminals(ClientManagementEJBBean.java:90)
at com.loyaltycentral.ejb.entity.service.client.EJSLocalStatelessClientManagementEJB_7b100336.getMerchantLocationTerminals(EJSLocalStatelessClientManagementEJB_7b100336.java:307)
at com.loyaltycentral.ejb.session.LoyaltyCentralEJBBean.findAllTerminalsByMerchantLocationId(LoyaltyCentralEJBBean.java:1953)
at com.loyaltycentral.ejb.session.EJSRemoteStatelessLoyaltyCentralEJB_e9271f65.findAllTerminalsByMerchantLocationId(EJSRemoteStatelessLoyaltyCentralEJB_e9271f65.java:1902)
at com.loyaltycentral.ejb.session._LoyaltyCentralEJB_Stub.findAllTerminalsByMerchantLocationId(_LoyaltyCentralEJB_Stub.java:4340)
at com.loyaltycentral.facade.LoyaltyCentral.findAllTerminalsByMerchantLocationId(LoyaltyCentral.java:679)
at com.ibm._jsp._deployLocationProgram._jspService(_deployLocationProgram.java:190)
at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:85)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:989)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:501)
at com.ibm.ws.wswebcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:464)
at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:122)
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:205)
at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:321)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:274)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:320)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
at com.loyaltycentral.web.LcRequestProcessor.process(LcRequestProcessor.java:100)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:763)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:989)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:501)
at com.ibm.ws.wswebcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:464)
at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:90)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:744)
at com.ibm.ws.wswebcontainer.WebContainer.handleRequest(WebContainer.java:1455)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:113)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:454)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:383)
at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:102)
at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:136)
at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:195)
at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:743)
at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:873)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1469)


Does anybody can help me?

http://www.google.com.au/search?q=%22don%27t+flush+the+Session+after+an+exception+occurs%22

Most likely, your app code is catching an exception from Hibernate somewhere earlier and is trying to continue using the failed Session instead of closing it and then re-trying with a new session. That is broken and will not work, as the Hibernate documentation clearly says.

Do your work within transactions and be prepared to re-try your work in a new session.

Yes, I do.

First, I tried to insert a row within a transaction, but the row validated constaint. So I have to insert it again after I corrected it.

I used persist or merge method to insert/update a row. of course I have to flush them so that a row can be insert into database.

so what should I do if I don't use flush? which is the place I should change?

Yes, you do what?

Anyway ... if the row fails a constraint check, the persistence exception thrown as a result trashes your Session. You'll need to close it and re-run your work in a new session with the fixed data.

If that's not very appealing, you can always pre-check the validity of your data rather than just inserting it and praying.

I mean I did my work within transaction.

I did close the session in every hibernate calling, which is in finally section.

because I used hibernate CRUD in session bean, which is CMT, so do I need to catch each exception and rollback the transaction?