java - Batch fetching returning null in JPA(Eclipse-Link) -

i have query batch fetch query being executed against 2 tables. these relations between them.

//category_on_page @entity @cacheable(true) @table(name="category_on_page") @jsonignoreproperties({"hibernatelazyinitializer", "handler", "fieldhandler"}) @entitylisteners({jpatoeofchangenotifier.class, jpaobjectchangesubscriber.class}) @was(com.stratahealth.shared.model.categoryonpage.class) public class categoryonformjpaimpl implements categoryonform {  @notnull @manytoone(targetentity=categoryjpaimpl.class, fetch=fetchtype.lazy) @joincolumn(name="category_id") @org.eclipse.persistence.annotations.batchfetch(value=org.eclipse.persistence.annotations.batchfetchtype.join,size=990) private category category;  }  //category entity @entity @cacheable(true) @table(name="category") @entitylisteners({jpatoeofchangenotifier.class, jpaobjectchangesubscriber.class}) @jsonignoreproperties({"hibernatelazyinitializer", "handler", "fieldhandler"}) @jsonidentityinfo(generator=objectidgenerators.propertygenerator.class, property="id") @was(com.stratahealth.shared.model.category.class) public class categoryjpaimpl implements category {  @onetomany(targetentity=categoryonformjpaimpl.class, mappedby="category") private set<categoryonform> categoryforms; 

the relationship on categorys on form. when batchfetch retrieves category page, null pointer thrown. stack trace.

javax.el.elexception: //usr/local/jsp/loader_194859196/meta-inf/resources/informationprofile.xhtml @28,59 listener="#{editinformationprofilecontroller.init()}": java.lang.nullpointerexception     @ com.sun.faces.facelets.el.tagmethodexpression.invoke(tagmethodexpression.java:111)     @ com.sun.faces.facelets.tag.jsf.core.declarativesystemeventlistener.processevent(eventhandler.java:128)     @ javax.faces.component.uicomponent$componentsystemeventlisteneradapter.processevent(uicomponent.java:2486)     @ javax.faces.event.systemevent.processlistener(systemevent.java:106)     @ com.sun.faces.application.applicationimpl.processlisteners(applicationimpl.java:2163)     @ com.sun.faces.application.applicationimpl.invokecomponentlistenersfor(applicationimpl.java:2111)     @ com.sun.faces.application.applicationimpl.publishevent(applicationimpl.java:289)     @ com.sun.faces.application.applicationimpl.publishevent(applicationimpl.java:247)     @ com.sun.faces.lifecycle.renderresponsephase.execute(renderresponsephase.java:107)     @ com.sun.faces.lifecycle.phase.dophase(phase.java:101)     @ com.sun.faces.lifecycle.lifecycleimpl.render(lifecycleimpl.java:139)     @ javax.faces.webapp.facesservlet.service(facesservlet.java:594)     @ org.apache.catalina.core.standardwrapper.service(standardwrapper.java:1550)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:343)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:217)     @ org.primefaces.webapp.filter.fileuploadfilter.dofilter(fileuploadfilter.java:100)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:256)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:217)     @ com.stratahealth.shared.common.filters.mainfilter.dofilter(mainfilter.java:30)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:256)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:217)     @ com.clickspace.csutilities.jsf.utf8characterencodingfilter.dofilter(utf8characterencodingfilter.java:15)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:256)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:217)     @ com.stratahealth.shared.common.filters.requireloginfilter.dofilter(requireloginfilter.java:63)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:256)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:217)     @ org.apache.catalina.core.standardwrappervalve.invoke(standardwrappervalve.java:279)     @ org.apache.catalina.core.standardcontextvalve.invoke(standardcontextvalve.java:175)     @ org.apache.catalina.core.standardpipeline.doinvoke(standardpipeline.java:655)     @ org.apache.catalina.core.standardpipeline.invoke(standardpipeline.java:595)     @ org.apache.catalina.core.standardhostvalve.invoke(standardhostvalve.java:161)     @ org.apache.catalina.connector.coyoteadapter.doservice(coyoteadapter.java:331)     @ org.apache.catalina.connector.coyoteadapter.service(coyoteadapter.java:231)     @ com.sun.enterprise.v3.services.impl.containermapper$adaptercallable.call(containermapper.java:317)     @ com.sun.enterprise.v3.services.impl.containermapper.service(containermapper.java:195)     @ com.sun.grizzly.http.processortask.invokeadapter(processortask.java:860)     @ com.sun.grizzly.http.processortask.doprocess(processortask.java:757)     @ com.sun.grizzly.http.processortask.process(processortask.java:1056)     @ com.sun.grizzly.http.defaultprotocolfilter.execute(defaultprotocolfilter.java:229)     @ com.sun.grizzly.defaultprotocolchain.executeprotocolfilter(defaultprotocolchain.java:137)     @ com.sun.grizzly.defaultprotocolchain.execute(defaultprotocolchain.java:104)     @ com.sun.grizzly.defaultprotocolchain.execute(defaultprotocolchain.java:90)     @ com.sun.grizzly.http.httpprotocolchain.execute(httpprotocolchain.java:79)     @ com.sun.grizzly.protocolchaincontexttask.docall(protocolchaincontexttask.java:54)     @ com.sun.grizzly.selectionkeycontexttask.call(selectionkeycontexttask.java:59)     @ com.sun.grizzly.contexttask.run(contexttask.java:71)     @ com.sun.grizzly.util.abstractthreadpool$worker.dowork(abstractthreadpool.java:532)     @ com.sun.grizzly.util.abstractthreadpool$worker.run(abstractthreadpool.java:513)     @ java.lang.thread.run(thread.java:662) caused by: java.lang.nullpointerexception     @ org.eclipse.persistence.queries.readallquery.executeobjectlevelreadquery(readallquery.java:431)     @ org.eclipse.persistence.queries.objectlevelreadquery.executedatabasequery(objectlevelreadquery.java:1168)     @ org.eclipse.persistence.queries.databasequery.execute(databasequery.java:899)     @ org.eclipse.persistence.queries.objectlevelreadquery.execute(objectlevelreadquery.java:1127)     @ org.eclipse.persistence.queries.readallquery.execute(readallquery.java:403)     @ org.eclipse.persistence.internal.sessions.abstractsession.internalexecutequery(abstractsession.java:3214)     @ org.eclipse.persistence.internal.sessions.abstractsession.executequery(abstractsession.java:1804)     @ org.eclipse.persistence.internal.sessions.abstractsession.executequery(abstractsession.java:1786)     @ org.eclipse.persistence.mappings.onetoonemapping.executebatchquery(onetoonemapping.java:806)     @ org.eclipse.persistence.mappings.foreignreferencemapping.extractresultfrombatchquery(foreignreferencemapping.java:643)     @ org.eclipse.persistence.internal.indirection.batchvalueholder.instantiate(batchvalueholder.java:58)     @ org.eclipse.persistence.internal.indirection.querybasedvalueholder.instantiate(querybasedvalueholder.java:116)     @ org.eclipse.persistence.internal.indirection.databasevalueholder.getvalue(databasevalueholder.java:89)     @ org.eclipse.persistence.internal.indirection.unitofworkvalueholder.instantiateimpl(unitofworkvalueholder.java:173)     @ org.eclipse.persistence.internal.indirection.unitofworkvalueholder.instantiate(unitofworkvalueholder.java:234)     @ org.eclipse.persistence.internal.indirection.databasevalueholder.getvalue(databasevalueholder.java:89)     @ com.stratahealth.shared.model.restimpl.jpa.categoryonformjpaimpl._persistence_get_category(categoryonformjpaimpl.java)     @ com.stratahealth.shared.model.restimpl.jpa.categoryonformjpaimpl.getcategory(categoryonformjpaimpl.java:60)     @ com.stratahealth.shared.common.services.impl.categoryserviceimpl.sortedcategoriesforformwithcaretypes(categoryserviceimpl.java:104)     @ com.stratahealth.shared.common.controllers.editinformationprofilecontroller.getcategoriesonformforcaretype(editinformationprofilecontroller.java:1421)     @ com.stratahealth.shared.common.controllers.editinformationprofilecontroller.init(editinformationprofilecontroller.java:442)     @ sun.reflect.generatedmethodaccessor1206.invoke(unknown source)     @ sun.reflect.delegatingmethodaccessorimpl.invoke(delegatingmethodaccessorimpl.java:25)     @ java.lang.reflect.method.invoke(method.java:597)     @ javax.el.beanelresolver.invokemethod(beanelresolver.java:779)     @ javax.el.beanelresolver.invoke(beanelresolver.java:528)     @ javax.el.compositeelresolver.invoke(compositeelresolver.java:257)     @ com.sun.el.parser.astvalue.invoke(astvalue.java:248)     @ com.sun.el.methodexpressionimpl.invoke(methodexpressionimpl.java:302)     @ com.sun.faces.facelets.el.tagmethodexpression.invoke(tagmethodexpression.java:105)     ... 49 more 

inside readallquery.executeobjectlevelreadquery method, null pointer being thrown. because "translationrow" being rendered null. not consistent, have been able reproduce luck.

the line npe is:

object sopobject = gettranslationrow().getsopobject(); 

when gettranslationrow() called, null value return , exception thrown. method npe happening inside eclipse link library.

  /**      * internal:      * execute query.      * rows , build object rows.      * @exception  databaseexception - error has occurred on database      * @return java.lang.object collection of objects resulting execution of query.      */     @override     protected object executeobjectlevelreadquery() throws databaseexception {         object result = null;          if (this.containerpolicy.overridesread()) {             this.executiontime = system.currenttimemillis();             return this.containerpolicy.execute();         }          if (this.descriptor.isdescriptorforinterface()) {             object returnvalue = this.descriptor.getinterfacepolicy().selectallobjectsusingmultipletablesubclassread(this);             this.executiontime = system.currenttimemillis();             return returnvalue;         }          if (this.descriptor.hastableperclasspolicy() && this.descriptor.isabstract()) {             result = this.containerpolicy.containerinstance();         } else {             object sopobject = gettranslationrow().getsopobject();             boolean useoptimization = false;             if (sopobject == null) {                 useoptimization = usesresultsetaccessoptimization();              }                      if (useoptimization) {                 databasecall call = ((datasourcecallquerymechanism)this.querymechanism).selectresultset();                 this.executiontime = system.currenttimemillis();                 statement statement = call.getstatement();                 resultset resultset = call.getresult();                 databaseaccessor dbaccessor = (databaseaccessor)getaccessor();                 boolean exceptionoccured = false;                 try {                     if (this.session.isunitofwork()) {                         result = registerresultsetinunitofwork(resultset, call.getfields(), call.getfieldsarray(), (unitofworkimpl)this.session, this.translationrow);                      } else {                         result = this.containerpolicy.containerinstance();                         this.descriptor.getobjectbuilder().buildobjectsfromresultsetinto(this, resultset, call.getfields(), call.getfieldsarray(), result);                     }                 } catch (sqlexception exception) {                     exceptionoccured = true;                     databaseexception commexception = dbaccessor.processexceptionforcommerror(this.session, exception, call);                     if (commexception != null) {                         throw commexception;                     }                     throw databaseexception.sqlexception(exception, call, dbaccessor, this.session, false);                 } {                     try {                         if (resultset != null) {                             resultset.close();                         }                         if (dbaccessor != null) {                             if (statement != null) {                                 dbaccessor.releasestatement(statement, call.getsqlstring(), call, this.session);                             }                         }                         if (call.hasallocatedconnection()) {                             getexecutionsession().releaseconnectionaftercall(this);                         }                     } catch (runtimeexception cleanupexception) {                         if (!exceptionoccured) {                             throw cleanupexception;                         }                     } catch (sqlexception cleanupsqlexception) {                         if (!exceptionoccured) {                             throw databaseexception.sqlexception(cleanupsqlexception, call, dbaccessor, this.session, false);                         }                     }                 }                             } else {                 list<abstractrecord> rows;                 if (sopobject != null) {                     object valuesiterator = this.containerpolicy.iteratorfor(gettranslationrow().getsopobject());                     int size = this.containerpolicy.sizefor(sopobject);                     rows =  new arraylist<abstractrecord>(size);                     while (this.containerpolicy.hasnext(valuesiterator)) {                         object membersopobject = this.containerpolicy.next(valuesiterator, this.session);                         databaserecord memberrow = new databaserecord(0);                         memberrow.setsopobject(membersopobject);                         rows.add(memberrow);                                             }                     this.executiontime = system.currenttimemillis();                 } else {                     rows = getquerymechanism().selectallrows();                     this.executiontime = system.currenttimemillis();                      // if using 1-m joins, must set rows.                     if (hasjoining() && this.joinedattributemanager.istomanyjoin()) {                         this.joinedattributemanager.setdataresults(rows, this.session);                     }                     // batch fetching in in requires access rows build id array.                     if ((this.batchfetchpolicy != null) && this.batchfetchpolicy.isin()) {                         this.batchfetchpolicy.setdataresults(rows);                     }                 }                  if (this.session.isunitofwork()) {                     result = registerresultinunitofwork(rows, (unitofworkimpl)this.session, this.translationrow, true);//                  } else {                     if (rows instanceof threadcursoredlist) {                         result = this.containerpolicy.containerinstance();                     } else {                         result = this.containerpolicy.containerinstance(rows.size());                     }                     this.descriptor.getobjectbuilder().buildobjectsinto(this, rows, result);                 }                  if (sopobject != null) {                     if (!this.descriptor.getobjectbuilder().issimple()) {                         // remove sopobject it's not stuck in value holder.                         (abstractrecord row : rows) {                             row.setsopobject(null);                         }                     }                 } else {                     if (this.shouldincludedata) {                         complexqueryresult complexresult = new complexqueryresult();                         complexresult.setresult(result);                         complexresult.setdata(rows);                         result = complexresult;                     }                 }             }         }          // add other (already registered) results , return them.         if (this.descriptor.hastableperclasspolicy()) {             result = this.containerpolicy.concatenatecontainers(                     result, this.descriptor.gettableperclasspolicy().selectallobjectsusingmultipletablesubclassread(this), this.session);         }          // if results empty, ensure cached still.         if (shouldcachequeryresults() && this.containerpolicy.isempty(result)) {             this.temporarycachedqueryresults = invalidobject.instance();         }          return result;     } 

from limited understanding of eclipse link.i believe translation row row retrieved batch fetch query. have ideas why being rendered null.....any appreciated.