I'm using jni4net to bridge between Java program & a C# dll file which controls a hardware device. The device and PC are connected by a network cable and I'm trying to handle the cable unplugged case while Java program is retrieving data from the hardware device via C# dll, frequently.
When unplugged the network cable, following exception is thrown by C# which is to be caught at Java side. But it's not happening even though I've tried catching with 'Exception', 'system.io.IOException' or 'Throwable' in Java.
What am I doing wrong? Is there other way around? Any input would be greatly appreciated. Thanks!
Code:
MyHardware f = new MyHardware();
f.Connection(DEVICE_IP);
if (f.ConnectionStatus()) {
try {
net.sf.jni4net.Ref<java.lang.String> refAmount = new Ref<String>(null),
refVolume = new Ref<String>(null), refPpu = new Ref<String>(null);
net.sf.jni4net.Ref<java.lang.Integer> refGrade = new Ref<Integer>(null),
refHose = new Ref<Integer>(hoseId);
f.GetLastSnapshot(Id, refAmount, refVolume, refPpu, refGrade, refHose);
} catch (Throwable t) {
logger.error("Error connecting device.");
}
}
Exception:
System.IO.IOException: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Send(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at MyHardwareThread.send(MyHardwareMsg msg)
at MyHardwareThread.sendReceive(MyHardwareMsg msg)
at MyHardwareClass.MyHardware.GetLastSnapshot(Int32 p_iPump, String& p_strAmount, String& p_strVolume, String& p_strPPU, Int32& p_iGrade, Int32& p_iHose)
at MyHardwareClass.__MyHardware.GetLastSnapshot20(IntPtr __envp, JniLocalHandle __obj, Int32 p_iPump, JniLocalHandle p_strAmount, JniLocalHandle p_strVolume, JniLocalHandle p_strPPU, JniLocalHandle p_iGrade, JniLocalHandle p_iHose)
at MyHardwareclass.MyHardware.GetLastSnapshot(Native Method)
at com.mno.MyHardware.pos.controller.pos.PosController.getLastSnapshot(PosController.java:774)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Unhandled Exception: System.InvalidOperationException: Once the socket has been disconnected, you can only reconnect again asynchronously, and only to a different EndPoint. BeginConnect must be called on a thread that won't exit until the operation has been completed.
at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
at System.Net.Sockets.TcpClient.Connect(IPEndPoint remoteEP)
at MyHardwareThread.connect()
at MyHardwareThread.mainLoop()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
Related
I am using hibernate to fetch only specific fields from and Entity. For that I am using Criteria API and using projections. I am getting ClassCastExcepiton when I try to traverse the list returned by the list() method of the Criteria API.
Please help me in finding out the missing of the below code.
#RequestMapping("/pResult")
public String retrieveLpnOnPagination(Model model) {
for (int i = 1; i <= 9; i += 3) {
List<MyLpn> lpns = lpnService.retrievePaginatedResult(i, 3,new String[]{"lpnId","status","whse"});
for (MyLpn lpn : lpns)
System.out.println(lpn.toString());
System.out.println();
}
return "home";
}
DaoImpl method
public List<MyLpn> retrievePResult(int i, int j, String[] projectionFields) {
Session currentSession = sessionFactory.getCurrentSession();
Criteria createCriteria = currentSession.createCriteria(MyLpn.class);
ProjectionList projectionList = Projections.projectionList();
for (String field : projectionFields)
projectionList.add(Projections.property(field));
createCriteria.setProjection(projectionList);
List<MyLpn> list = createCriteria.list();
for (MyLpn lpn : list)
System.out.println(lpn.toString());
return list;
}
Exception
SEVERE: Servlet.service() for servlet [spring] in context with path [/MyW2014] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.w.model.MyLpn] with root cause
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.w.model.MyLpn
at com.wmos.dao.LpnDaoImpl.retrievePResult(LpnDaoImpl.java:88)
at com.w.service.LpnService.retrievePaginatedResult(LpnService.java:43)
at com.wmos.service.LpnService$$FastClassBySpringCGLIB$$4e814eab.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655)
at com.wmos.service.LpnService$$EnhancerBySpringCGLIB$$bec224d4.retrievePaginatedResult(<generated>)
at com.wmos.controller.LpnController.retrieveLpnOnPagination(LpnController.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1136)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Thank you.
Try this
createCriteria.setResultTransformer(Transformers.aliasToBean(MyLpn.class));
List<MyLpn> list = createCriteria.list();
Getting socket timeout exception frequently in my web application. Let me explain what's the issue is while reading data at very first time application works fine and according to my idea after some time it goes to ideal state. While executing it again(after some time), getting socket timeout error as mentioned below. Please help me in finding solution, Thank you.
Dec 12, 2017 9:17:31 AM
com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The exception contained within MappableContainerException could not
be mapped to a response, re-throwing to the HTTP container
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:535)
at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:504)
at org.apache.coyote.http11.InternalInputBuffer$InputStreamInputBuffer.doRead(InternalInputBuffer.java:566)
at org.apache.coyote.http11.filters.IdentityInputFilter.doRead(IdentityInputFilter.java:137)
at org.apache.coyote.http11.AbstractInputBuffer.doRead(AbstractInputBuffer.java:341)
at org.apache.coyote.Request.doRead(Request.java:431)
at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:290)
at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:449)
at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:315)
at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:200)
at org.codehaus.jackson.impl.StreamBasedParserBase.loadMore(StreamBasedParserBase.java:107)
at org.codehaus.jackson.impl.Utf8StreamParser._skipWS(Utf8StreamParser.java:1689)
at org.codehaus.jackson.impl.Utf8StreamParser.nextToken(Utf8StreamParser.java:310)
at org.codehaus.jackson.map.deser.ArrayDeserializers$ByteDeser.deserialize(ArrayDeserializers.java:260)
at org.codehaus.jackson.map.deser.ArrayDeserializers$ByteDeser.deserialize(ArrayDeserializers.java:229)
at org.codehaus.jackson.map.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:230)
at org.codehaus.jackson.map.deser.SettableBeanProperty$MethodProperty.deserializeAndSet(SettableBeanProperty.java:334)
at org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:495)
at org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:351)
at org.codehaus.jackson.map.ObjectMapper._readValue(ObjectMapper.java:2112)
at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1004)
at org.codehaus.jackson.jaxrs.JacksonJsonProvider.readFrom(JacksonJsonProvider.java:410)
at com.sun.jersey.json.impl.provider.entity.JacksonProviderProxy.readFrom(JacksonProviderProxy.java:139)
at com.sun.jersey.spi.container.ContainerRequest.getEntity(ContainerRequest.java:474)
at com.sun.jersey.server.impl.model.method.dispatch.EntityParamDispatchProvider$EntityInjectable.getValue(EntityParamDispatchProvider.java:123)
at com.sun.jersey.server.impl.inject.InjectableValuesProvider.getInjectableValues(InjectableValuesProvider.java:46)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$EntityParamInInvoker.getParams(AbstractResourceMethodDispatchProvider.java:153)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:183)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.filters.CorsFilter.handleNonCORS(CorsFilter.java:438)
at org.apache.catalina.filters.CorsFilter.doFilter(CorsFilter.java:179)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
// Variables to build a client to call the Web Resource.
Client c = Client.create();
// Declaring WebResource to connect to the web application
WebResource r =
c.resource(UriBuilder.fromUri(ReallyMakeConstants.URL_SERVER)
.build());
MultivaluedMap<String, String> retrieveBidRequests = new
MultivaluedMapImpl();
// Binding the values
retrieveBidRequests.add("vendorId", vendorId);
retrieveBidRequests.add("makeType", makeType);
retrieveBidRequests.add("selectedStatus", selectedBidStatus);
String veRequestsList = r.path("bidResource")
.path("retrieveVendorBidRequests2")
.queryParams(retrieveBidRequests)
.accept(MediaType.APPLICATION_JSON).get(String.class);
String bidRequestsList = request
.getAttribute("veRequestsList ").toString();
JSONParser bidRequestJsonParser = new JSONParser();
JSONArray bidRequestJsonArray;
BidRequest bidRequest = null;
Model model = null;
Object obj = bidRequestJsonParser.parse(bidRequestsList);
bidRequestJsonArray = (JSONArray) obj;
I am converting all entities to JSON using Gson. I am using the Oracle 11g database, and when I open dialog the following exception occurs when I want to convert:
org.hibernate.exception.SQLGrammarException: ORA-01722: número no válido
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:82)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:129)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at com.sun.proxy.$Proxy321.executeQuery(Unknown Source)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1897)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1698)
at org.hibernate.loader.Loader.doQuery(Loader.java:832)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:293)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:263)
at org.hibernate.loader.Loader.loadCollection(Loader.java:2094)
at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:61)
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:678)
at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:82)
at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:1801)
at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:524)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:212)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:520)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:125)
at org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:266)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:95)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:113)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:240)
at com.google.gson.Gson.toJson(Gson.java:605)
at com.google.gson.Gson.toJson(Gson.java:584)
at com.google.gson.Gson.toJson(Gson.java:539)
at com.google.gson.Gson.toJson(Gson.java:519)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.el.parser.AstValue.invoke(AstValue.java:278)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:273)
at org.apache.myfaces.view.facelets.el.ContextAwareTagMethodExpression.invoke(ContextAwareTagMethodExpression.java:96)
at org.apache.myfaces.view.facelets.tag.jsf.core.EventHandler$Listener.processEvent(EventHandler.java:273)
at javax.faces.component.UIComponent$EventListenerWrapper.processEvent(UIComponent.java:1579)
at javax.faces.event.SystemEvent.processListener(SystemEvent.java:43)
at org.apache.myfaces.application.ApplicationImpl._traverseListenerList(ApplicationImpl.java:2493)
at org.apache.myfaces.application.ApplicationImpl.publishEvent(ApplicationImpl.java:586)
at org.apache.myfaces.application.ApplicationImpl.publishEvent(ApplicationImpl.java:616)
at javax.faces.application.ApplicationWrapper.publishEvent(ApplicationWrapper.java:336)
at javax.faces.application.ApplicationWrapper.publishEvent(ApplicationWrapper.java:336)
at javax.faces.application.ApplicationWrapper.publishEvent(ApplicationWrapper.java:336)
at org.apache.deltaspike.jsf.impl.injection.InjectionAwareApplicationWrapper.publishEvent(InjectionAwareApplicationWrapper.java:148)
at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:84)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:241)
at org.apache.deltaspike.jsf.impl.listener.request.DeltaSpikeLifecycleWrapper.render(DeltaSpikeLifecycleWrapper.java:111)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:199)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:100)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at util.HibernateSessionRequestFilter.executeChain(HibernateSessionRequestFilter.java:91)
at util.HibernateSessionRequestFilter.doFilter(HibernateSessionRequestFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
And how do I convert using the following code?
builder = new GsonBuilder();
builder.excludeFieldsWithoutExposeAnnotation()
.setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE)
.registerTypeAdapterFactory(HibernateProxyTypeAdapter.FACTORY)
.excludeFieldsWithModifiers(Modifier.STATIC)
.serializeNulls();
gson2 = builder.create();
this.setJson(gson2.toJson(obj));
I don't use native SQL queries before executing.
I wrote a custom strategy in order to clone an entity TrainTimetable with its collection of slots.
Below an extract of the model :
Entity('TrainTimetable') {
list 'slots' , ref:'Slot', composition:true
}
Entity('Slot') {
reference 'trainTimetable' , ref:'TrainTimetable', reverse:'TrainTimetable-slots'
}
And below the method :
package fr.yc.rail.backend;
import java.util.ArrayList;
import java.util.List;
import org.jspresso.framework.model.entity.IEntity;
import org.jspresso.framework.model.entity.IEntityFactory;
import org.jspresso.framework.model.entity.SmartEntityCloneFactory;
import fr.yc.rail.model.Slot;
import fr.yc.rail.model.TrainTimetable;
public class CloneTrainTimetableFactory extends SmartEntityCloneFactory {
#Override
public <E extends IEntity> E cloneEntity(E entityToClone,
IEntityFactory entityFactory) {
TrainTimetable clonedTrainTimetable = (TrainTimetable) super.cloneEntity(entityToClone, entityFactory);
TrainTimetable trainTimetableToClone = (TrainTimetable) entityToClone;
List<Slot> clonedSlots = new ArrayList<Slot>();
trainTimetableToClone.getSlots().each {
Slot clonedSlot = super.cloneEntity(it, entityFactory);
clonedSlots.add(clonedSlot);
}
clonedTrainTimetable.setSlots(clonedSlots);
return (E) clonedTrainTimetable;
}
}
When the method is called, the code below raises the ConcurrentModificationException error on the second iteration :
trainTimetableToClone.getSlots().each {
Slot clonedSlot = super.cloneEntity(it, entityFactory);
clonedSlots.add(clonedSlot);
}
Below the stack trace :
ERROR <2015-06-09 18:13:11,193> org.jspresso.framework.application.frontend.controller.AbstractFrontendController : An unexpected error occurred for user demo on session 4379dc1b.
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.next(Unknown Source)
at org.hibernate.collection.internal.AbstractPersistentCollection$IteratorProxy.next(AbstractPersistentCollection.java:774)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:1378)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:1372)
at org.codehaus.groovy.runtime.dgm$149.invoke(Unknown Source)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:271)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:53)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
at fr.yc.rail.backend.CloneTrainTimetableFactory.cloneEntity(CloneTrainTimetableFactory.groovy:25)
at org.jspresso.framework.application.backend.action.CloneComponentCollectionAction.cloneElement(CloneComponentCollectionAction.java:61)
at org.jspresso.framework.application.backend.action.AbstractCloneCollectionAction.getAddedComponents(AbstractCloneCollectionAction.java:71)
at org.jspresso.framework.application.backend.action.AbstractAddCollectionToMasterAction.execute(AbstractAddCollectionToMasterAction.java:78)
at org.jspresso.framework.application.backend.AbstractBackendController.execute(AbstractBackendController.java:403)
at org.jspresso.framework.application.frontend.controller.AbstractFrontendController.executeBackend(AbstractFrontendController.java:1536)
at org.jspresso.framework.application.frontend.controller.AbstractFrontendController.execute(AbstractFrontendController.java:576)
at org.jspresso.framework.application.action.AbstractAction.execute(AbstractAction.java:114)
at org.jspresso.framework.application.frontend.controller.AbstractFrontendController.executeFrontend(AbstractFrontendController.java:1549)
at org.jspresso.framework.application.frontend.controller.AbstractFrontendController.execute(AbstractFrontendController.java:578)
at org.jspresso.framework.view.remote.RemoteActionFactory$ActionAdapter.actionPerformed(RemoteActionFactory.java:235)
at org.jspresso.framework.application.frontend.controller.remote.AbstractRemoteController.handleCommand(AbstractRemoteController.java:440)
at org.jspresso.framework.application.frontend.controller.remote.AbstractRemoteController.handleCommands(AbstractRemoteController.java:202)
at org.jspresso.framework.application.startup.remote.RemoteStartup.handleCommands(RemoteStartup.java:88)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.sf.qooxdoo.rpc.RemoteCallUtils.callCompatibleMethod(RemoteCallUtils.java:469)
at net.sf.qooxdoo.rpc.RpcServlet.handleRPC(RpcServlet.java:374)
at net.sf.qooxdoo.rpc.RpcServlet.doPost(RpcServlet.java:481)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jspresso.framework.util.http.HttpRequestHolder.doFilter(HttpRequestHolder.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
The error means that I am iterating on a collection that is changing in size, but I don't know how to get rid of it.
You have a 1-N bi-directional association between TrainTimetable and Slot. This means that whenever you update one side of the association, Jspresso will take care of updating the other side in order to keep model consistency, e.g. :
if you set the trainTimetable property on a slot, the slot will be added to the reverse slots collection of the train timetable.
if you add a slot to the slotsproperty of a train timetable, then the trainTimetable reverse property of the added slot will be updated to the train timetable.
In the following code :
Slot clonedSlot = super.cloneEntity(it, entityFactory);
the clonedSlot will be added to the trainTimeTableToClone slots due to the rules explained before. So the iterated collection actually changes.
In order to fix the problem, making a copy of the collection before iterating it should be enough, i.e. :
trainTimetableToClone.getSlots().collect().each {
My code is throwing a NullPointerException, when i select an null Arraylist
this is the stack trace:
javax.el.ELException: /jsf/projet/phases/viewPhases.xhtml #27,170 value="#{PhaseComponent.listPhaseTaches(PhaseComponent.phase.idphase)}": java.lang.NullPointerException
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:111)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:190)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:178)
at javax.faces.component.UIData.getValue(UIData.java:554)
at org.primefaces.component.datatable.DataTable.getValue(DataTable.java:910)
at org.primefaces.component.api.UIData.getDataModel(UIData.java:615)
at javax.faces.component.UIData.getRowCount(UIData.java:339)
at org.primefaces.component.api.UIData.calculateFirst(UIData.java:161)
at org.primefaces.component.datatable.DataTableRenderer.preEncode(DataTableRenderer.java:107)
at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:81)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:879)
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:74)
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:57)
at org.primefaces.component.panel.PanelRenderer.encodeContent(PanelRenderer.java:204)
at org.primefaces.component.panel.PanelRenderer.encodeMarkup(PanelRenderer.java:121)
at org.primefaces.component.panel.PanelRenderer.encodeEnd(PanelRenderer.java:58)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:879)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:164)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:849)
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:70)
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:57)
at org.primefaces.component.layout.LayoutUnitRenderer.encodeEnd(LayoutUnitRenderer.java:51)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:879)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:389)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:127)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:117)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:135)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:309)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:113)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at com.gestion.projet.web.jsf.PhaseComponentImpl.listPhaseTaches(PhaseComponentImpl.java:268)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
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.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy56.listPhaseTaches(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy9.listPhaseTaches(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at javax.el.BeanELResolver.invoke(BeanELResolver.java:183)
at javax.el.CompositeELResolver.invoke(CompositeELResolver.java:161)
at com.sun.el.parser.AstValue.getValue(AstValue.java:111)
at com.sun.el.parser.AstValue.getValue(AstValue.java:163)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:106)
... 56 more
an this is the method that i want to handle the exception it returns an ArrayList :
public List<Tache> listPhaseTaches(Integer idphaseKey) {
return new java.util.ArrayList<Tache>(phaseDAO.findPhaseByPrimaryKey(idphaseKey).getTaches());
}
The problem is I don't know what i should do for handling NullPointerException for a method that returns an Arraylist
List list = someMethod();
if(list!=null){
//your logic
}
else{
return new List<T>();
}
Make sure that you return not-null value
you can handle this like
List list = someMethod();
if(list!=null){
//your logic
}
else{
}
your error lies either at phaseDAO is null or phaseDAO.findPhaseByPrimaryKey(idphaseKey) this returns null OR phaseDAO.findPhaseByPrimaryKey(idphaseKey).getTaches() this returns null
Use this >>
public List<Tache> listPhaseTaches(Integer idphaseKey) {
if(phaseDAO!=null){
if(phaseDAO.findPhaseByPrimaryKey(idphaseKey)!=null){
if(phaseDAO.findPhaseByPrimaryKey(idphaseKey)!=null){
return new ArrayList(phaseDAO.findPhaseByPrimaryKey(idphaseKey));
}
}
}
return null;
}
Provide the following null checks:
phaseDAO != null
phaseDAO.findPhaseByPrimaryKey(idphaseKey) != null
phaseDAO.findPhaseByPrimaryKey(idphaseKey).getTaches() != null