Exception while implementing LazyModel for primefaces datalist - spring

I am trying to implement the lazy loading model for the primefaces datalist similar to datatable as shown here.
My initial code with the normal AJAX pagination feature works absolutely fine. However, when I try using the lazy loading model, I get the exception below when the page loads :
com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException
SEVERE: Error Rendering View[/pages/index.xhtml]
java.io.NotSerializableException: java.util.ArrayList$SubList
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1100)
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:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1362)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1170)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1100)
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:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at com.sun.faces.renderkit.ClientSideStateHelper.doWriteState(ClientSideStateHelper.java:325)
at com.sun.faces.renderkit.ClientSideStateHelper.writeState(ClientSideStateHelper.java:173)
at com.sun.faces.renderkit.ResponseStateManagerImpl.writeState(ResponseStateManagerImpl.java:122)
at com.sun.faces.application.StateManagerImpl.writeState(StateManagerImpl.java:166)
at com.sun.faces.application.view.WriteBehindStateWriter.flushToWriter(WriteBehindStateWriter.java:225)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:418)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Here's the code of index.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:p="http://primefaces.org/ui">
<ui:composition template="/pages/templates/template.xhtml">
<ui:define name="content">
<h:form prependId="false" id="form">
<p:dataList value="#{movies.lazyMovieModel}" var="movie" id="movies" paginator="true" rows="10"
paginatorTemplate="{FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink}"
type="none" paginatorAlwaysVisible="false" lazy="true">
<h:outputText value="#{movie.movieName}, #{movie.releaseYear}" style="margin-left:10px">
</h:outputText>
<br/>
</p:dataList>
</h:form>
</ui:define>
</ui:composition>
</html>
MovieListBean.java
import org.primefaces.model.LazyDataModel;
import com.clixflix.enitities.Movie;
import com.clixflix.jsf.extensions.LazyMovieDataModel;
#ManagedBean(name = "movies")
#ViewScoped
public class MovieListBean extends BaseBean implements Serializable
{
private static final long serialVersionUID = -5719443344065177588L;
private LazyDataModel<Movie> lazyMovieModel;
#PostConstruct
public void initialize() {
lazyMovieModel = new LazyMovieDataModel();
}
public LazyDataModel<Movie> getLazyMovieModel()
{
List<Movie> movieList = getServiceLocator().getMovieService().getMovieList();
((LazyMovieDataModel) lazyMovieModel).setMovieList(movieList);
return lazyMovieModel;
}
}
LazyMovieDataModel.java (LazyModel implementation)
public class LazyMovieDataModel extends LazyDataModel<Movie>
{
private static final long serialVersionUID = 8745562148994455749L;
private List<Movie> movieList;
public LazyMovieDataModel() {
this.movieList = Collections.emptyList();
}
#Override
public List<Movie> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
// Sorting
if (null != sortField) {
LazySorter sorter = new LazySorter(sortField, sortOrder);
Collections.sort(movieList, sorter);
sorter = null;
}
// RowCount
int rowCount = movieList.size();
this.setRowCount(rowCount);
// Pagination
if (rowCount > pageSize) {
return movieList.subList(first, (first + pageSize));
}
else {
return movieList;
}
}
private class LazySorter implements Comparator<Movie>
{
private String sortField;
private SortOrder sortOrder;
LazySorter(String sortField, SortOrder sortOrder) {
this.sortField = sortField;
this.sortOrder = sortOrder;
}
#SuppressWarnings("unchecked")
#Override
public int compare(Movie movie1, Movie movie2) {
Object value1 = null, value2 = null;
try {
value1 = Movie.class.getField(this.sortField).get(movie1);
value2 = Movie.class.getField(this.sortField).get(movie2);
int value = ((Comparable<Object>) value1).compareTo(value2);
return SortOrder.ASCENDING.equals(sortOrder) ? value : -1 * value;
}
catch (IllegalArgumentException | IllegalAccessException | NoSuchFieldException | SecurityException e) {
e.printStackTrace();
return 0;
}
}
}
public void setMovieList(List<Movie> movieList) {
this.movieList = movieList;
}
}
I am assuming the exception is at this line:
return movieList.subList(first, (first + pageSize));
Could anyone please guide me as to what am I missing?
Also, I observe in the logs, that when I use the lazymodel, the DB gets queried three times but when I use the normal AJAX pagination, the DB is queried only once :|
UPDATE: I figured out the reason for the DB being queried 3 times. It was because I was calling my service in the getter of the LazyModel instead of only in the load method.
I made the following changes in the classes:
LazyMovieDataModel.java
public class LazyMovieDataModel extends LazyDataModel<Movie>
{
private static final long serialVersionUID = 8745562148994455749L;
public LazyMovieDataModel() {}
#Override
public List<Movie> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
List<Movie> movieList = getServiceLocator().getMovieService().getMovieList(first, (first + pageSize));
// RowCount
int rowCount = ((Number)getServiceLocator().getMovieService().getMovieCount()).intValue();
this.setRowCount(rowCount);
}
}
LazyModel getter in MovieListBean.java
/* Removed PostConstruct init method */
public LazyDataModel<Movie> getLazyMovieModel()
{
return lazyMovieModel;
}
The above changes work fine on the initial page load. However, when I hit the next page button (or any pagination button) I get an NPE for getServiceLocator() in the load method.
The serviceLocator is a protected access modified managed property inherited from BaseBean and injected using Spring.
Any reason why the getter returns null on subsequent invokes ???

ArrayList$SubList is a problem. The subList returned does not implement serializable.
Try using:
return new ArrayList(movieList.subList(first, (first + pageSize)));

Same problem in this link.There are 2 load methods in LazyDataModel:
public List<T> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,String> filters) {
throw new UnsupportedOperationException("Lazy loading is not implemented.");
}
public List<T> load(int first, int pageSize, List<SortMeta> multiSortMeta,Map<String,String> filters) {
throw new UnsupportedOperationException("Lazy loading is not implemented.");
}
This is where the error is thrown. You are using multisort, so you should override the second.Default method is the first one.

Related

Can I add any object to Model in Spring MVC?

I wanted to add a bean to model in Spring MVC Controller. But, validator exception is thrown:
Illegalstate exception.
Can anyone guide me to submit a form and display the content which I get after form submission? In this case, I need to use a bean to display all my information in view.
Like:
model.addAttribute("simple", new Student());
But, I am keep getting IllegaStateException from validator.
Download:
https://sites.google.com/site/jimjicky/SpringFormValidation.rar?attredirects=0&d=1
Controller:
#Controller
public class EmployeeController {
private static final Logger logger = LoggerFactory
.getLogger(EmployeeController.class);
private Map<Integer, Employee> emps = null;
#Autowired
#Qualifier("employeeValidator")
private Validator validator;
#InitBinder
private void initBinder(WebDataBinder binder) {
binder.setValidator(validator);
}
public EmployeeController() {
emps = new HashMap<Integer, Employee>();
}
#ModelAttribute("employee")
public Employee createEmployeeModel() {
// ModelAttribute value should be same as used in the empSave.jsp
return new Employee();
}
#ModelAttribute("student")
public Student createStudentModel() {
// ModelAttribute value should be same as used in the empSave.jsp
return new Student();
}
#RequestMapping(value = "/emp/save", method = RequestMethod.GET)
public String saveEmployeePage(Model model) {
logger.info("Returning empSave.jsp page");
return "empSave";
}
#RequestMapping(value = "/emp/save.do", method = RequestMethod.POST)
public String saveEmployeeAction(
#ModelAttribute("employee") #Validated Employee employee,#ModelAttribute("student")Student student,
BindingResult bindingResult, Model model) {
if (bindingResult.hasErrors()) {
logger.info("Returning empSave.jsp page");
return "empSave";
}
logger.info("Returning empSaveSuccess.jsp page");
model.addAttribute("emp", employee);
model.addAttribute("student", createStudentModel());
emps.put(employee.getId(), employee);
return "empSaveSuccess";
}
}
Validator:
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;
import com.journaldev.spring.form.model.Employee;
public class EmployeeFormValidator implements Validator {
//which objects can be validated by this validator
#Override
public boolean supports(Class<?> paramClass) {
return Employee.class.equals(paramClass);
}
#Override
public void validate(Object obj, Errors errors) {
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "id", "id.required");
Employee emp = (Employee) obj;
if(emp.getId() <=0){
errors.rejectValue("id", "negativeValue", new Object[]{"'id'"}, "id can't be negative");
}
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "name.required");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "role", "role.required");
}
}
Stack Trace
java.lang.IllegalStateException: Invalid target for Validator [com.journaldev.spring.form.validator.EmployeeFormValidator#1625cd8]: com.journaldev.spring.form.model.Student#bd8550
org.springframework.validation.DataBinder.assertValidators(DataBinder.java:495)
org.springframework.validation.DataBinder.setValidator(DataBinder.java:486)
com.journaldev.spring.form.controllers.EmployeeController.initBinder(EmployeeController.java:38)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:606)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.method.annotation.InitBinderDataBinderFactory.initBinder(InitBinderDataBinderFactory.java:62)
org.springframework.web.bind.support.DefaultDataBinderFactory.createBinder(DefaultDataBinderFactory.java:53)
org.springframework.web.method.annotation.ModelFactory.updateBindingResult(ModelFactory.java:222)
org.springframework.web.method.annotation.ModelFactory.updateModel(ModelFactory.java:206)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.getModelAndView(RequestMappingHandlerAdapter.java:852)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:755)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:690)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
Based on the information provided try changing your InitBinder to following:
#InitBinder("employee")
private void initBinder(WebDataBinder binder) {
binder.setValidator(validator);
}
The reason this works is because of the value provided, in this case the value being "employee".
public abstract String[] value
The names of command/form attributes and/or request parameters that this init-binder method is supposed to apply to.
In your form you have multiple objects, without advising the #InitBinder what object to validate it attempted to validate your Student object as well, thus failing as it didn't meet the class requirements.
By specifying "employee" it basically ensured it only applied the validation against the Employee object.

java.lang.ClassCastException: java.util.HashMap cannot be cast to ClassObject

I have a problem with <p:dataTable> in PrimeFaces, I can not find the error.
Class UsuarioAsig:
public class UsuarioAsig {
private BigDecimal codigopersona;
private String nombre;
private String paterno;
private String materno;
private String login;
private String observacion;
private String tipocontrol;
private String externo;
private String habilitado;
private String nombreperfil;
private BigDecimal codigousuario; ...get and set...}
Class UsuarioAsigListaDataModel:
public class UsuarioAsigListaDataModel extends ListDataModel<UsuarioAsig> implements SelectableDataModel<UsuarioAsig> {
public UsuarioAsigListaDataModel(){}
public UsuarioAsigListaDataModel(List<UsuarioAsig> data){super(data);}
#Override
public UsuarioAsig getRowData(String rowKey) {
#SuppressWarnings("unchecked")
List<UsuarioAsig> listaUsuarioAsigLectura = (List<UsuarioAsig>) getWrappedData();
for (UsuarioAsig usuarioAsig : listaUsuarioAsigLectura) {
if (usuarioAsig.getCodigopersona().equals(rowKey)) { return usuarioAsig; }
}
return null;
}
#Override
public Object getRowKey(UsuarioAsig usuarioAsig) {
return usuarioAsig.getCodigopersona();
}}
Controller UsuarioAsigController:
#Controller("usuarioAsigController")
#Scope(value = "session")
public class UsuarioAsigController {
private List<UsuarioAsig> listaUsuarioAsig;
private HashMap<String, Object> selUsuarioAsig;
private UsuarioAsigListaDataModel mediumUsuarioAsigModel;
#Autowired
UsuarioService usuarioService;
...
public List<UsuarioAsig> getListaUsuarioAsig() {
listaUsuarioAsig = usuarioService.selectAsig();
return listaUsuarioAsig;
}
public void setListaUsuarioAsig(List<UsuarioAsig> listaUsuarioAsig) {
this.listaUsuarioAsig = listaUsuarioAsig;
}
public void setMediumUsuarioAsigModel(UsuarioAsigListaDataModel mediumUsuarioAsigModel) {
this.mediumUsuarioAsigModel = mediumUsuarioAsigModel;
}
public UsuarioAsigListaDataModel getMediumUsuarioAsigModel() {
listaUsuarioAsig = usuarioService.selectAsig();
mediumUsuarioAsigModel = new UsuarioAsigListaDataModel(listaUsuarioAsig);
return mediumUsuarioAsigModel;
}
public void onRowSelect(SelectEvent event) {
FacesMessage msg = new FacesMessage("Usuario seleccionado", ((UsuarioAsig) event.getObject()).getNombre());
FacesContext.getCurrentInstance().addMessage(null, msg);
}
}
the error is generated when you click on one of the lines of datatable:
asiginst.xhtml:
<h:form id="form">
<p:growl id="msgs" showDetail="true" />
<p:dataTable id="usuarioAsigListaDataModel" var="usuarioAsig"
value="#{usuarioAsigController.mediumUsuarioAsigModel}"
rowKey="#{usuarioAsig.codigopersona}"
selection="#{usuarioAsigController.selUsuarioAsig}"
selectionMode="single" paginator="true" rows="10">
<p:ajax event="rowSelect"
listener="#{usuarioAsigController.onRowSelect}"
update=":form:msgs" />
<p:column headerText="Código" style="width:10%">#{usuarioAsig.codigopersona}</p:column>
<p:column headerText="Nombre" style="width:32%">#{usuarioAsig.nombre}</p:column>
<p:column headerText="Apellidos" style="width:32%">#{usuarioAsig.paterno} #{usuarioasig.materno}</p:column>
<p:column headerText="Tipo Control" style="width:20%">#{usuarioAsig.tipocontrol}</p:column>
<p:column headerText="Habilitado" style="width:6%">#{usuarioAsig.habilitado}</p:column>
</p:dataTable>
</h:form>
THE ERROR IS GENERATED:
WARNING: asiginst.xhtml #51,103 listener="#{usuarioAsigController.onRowSelect}": java.lang.ClassCastException: java.util.HashMap cannot be cast to com.datos.entidades.qry.UsuarioAsig
javax.el.ELException: asiginst.xhtml #51,103 listener="#{usuarioAsigController.onRowSelect}": java.lang.ClassCastException: java.util.HashMap cannot be cast to com.datos.entidades.qry.UsuarioAsig
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:111)
at org.primefaces.behavior.ajax.AjaxBehaviorListenerImpl.processArgListener(AjaxBehaviorListenerImpl.java:69)
at org.primefaces.behavior.ajax.AjaxBehaviorListenerImpl.processAjaxBehavior(AjaxBehaviorListenerImpl.java:56)
at org.primefaces.event.SelectEvent.processListener(SelectEvent.java:40)
at javax.faces.component.behavior.BehaviorBase.broadcast(BehaviorBase.java:102)
at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:760)
at javax.faces.component.UIData.broadcast(UIData.java:1071)
at javax.faces.component.UIData.broadcast(UIData.java:1093)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.ClassCastException: java.util.HashMap cannot be cast to com.datos.entidades.qry.UsuarioAsig
at com.controller.UsuarioAsigController.onRowSelect(UsuarioAsigController.java:217)
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:601)
at org.apache.el.parser.AstValue.invoke(AstValue.java:264)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
... 29 more
I'm assuming that the HashMap<String, Object> selUsuarioAsig is your selection.
Then in the method
public void onRowSelect(SelectEvent event) {
FacesMessage msg = new FacesMessage("Usuario seleccionado", ((UsuarioAsig) event.getObject()).getNombre());
FacesContext.getCurrentInstance().addMessage(null, msg);
}
You are attempting to cast the HashMap to a UsuarioAsig: ((UsuarioAsig) event.getObject())
as examples of http://www.primefaces.org/showcase/ui/data/datatable/selection.xhtml, not generate error in other tables, after much testing error was mybatis mapper, since the resulMap was in type Map.

How to get Dynamic Drop Down Box in JSP

I want to populate a dropdown box in Spring MVC i tried to do this but i am getting null pointer exception
this is my controller:
public class CatalogueController {
private CatalogueService catalogueService;
private PublisherService publisherService;
private SubjectService subjectService;
// some code and i generated setter and getter methods
............
#RequestMapping(value="/catalogue/new.action", method=RequestMethod.GET)
public ModelAndView newMember() throws Exception {
ModelAndView mvc= null;
mvc = new ModelAndView("catalogue/catalogueForm", "catalogueForm", new CatalogueBase());
mvc.addObject("copyDetailForm", new CatalogueCopyDetails());
List<Publisher> publist = publisherService.getPublisherList();
mvc.addObject("publist", publist);
List<Subject> subjectlist = subjectService.getSubjectList();
mvc.addObject("subjectlist", subjectlist);
return mvc;
}
this is my service method :
#Override
public List<Publisher> getPublisherList() {
List<Publisher> list = publisherDAO.getPublisher();
return list;
}
#Override
public List<Subject> getSubjectList() {
List<Subject> list = subjectDAO.getSubjects();
return list;
}
this is my DAO Method:
#SuppressWarnings("unchecked")
public List<Publisher> getPublisher() {
Query qry = getSession().createQuery("from Publisher");
return qry.list();
}
#SuppressWarnings("unchecked")
public List<Subject> getSubjects() {
Query qry = getSession().createQuery("from Subject");
return qry.list();
}
finally this is my JSP page :
<form:form commandname="catalogueForm" action="${pageContext.request.contextPath}/catalogue/create.action" method="post" modelAttribute="catalogueForm">
<form:select path="publisher.id" id="publisher.id">
<form:options items="${publist}" itemValue="id" itemLabel="name" />
</form:select>
<form:select path="subject.id" id="subject.id">
<form:options items="${subjectlist}" itemValue="id" itemLabel="name" />
</form:select>
</form:form>
This is Stack Trace:
java.lang.NullPointerException
at com.easylib.elibrary.webapp.controller.catalogue.CatalogueController.newMember(CatalogueController.java:80)
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:601)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:100)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:604)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:565)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
You are getting the npe at line 80 of your controller, but I can't see which line that is in your question.
My guess is that you haven't wired in your services correctly and either "publisherService" or "subjectService" is null.

Lazy loading of child throwing session error

I'm the following error when calling purchaseService.updatePurchase(purchase) inside my TagController:
SEVERE: Servlet.service() for servlet [PurchaseAPIServer] in context with path [/PurchaseAPIServer] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.app.model.Purchase.tags, no session or session was closed] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.app.model.Purchase.tags, no session or session was closed
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383)
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:368)
at org.hibernate.collection.PersistentSet.add(PersistentSet.java:212)
at com.app.model.Purchase.addTags(Purchase.java:207)
at com.app.controller.TagController.createAll(TagController.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
TagController:
#RequestMapping(value = "purchases/{purchaseId}/tags", method = RequestMethod.POST, params = "manyTags")
#ResponseStatus(HttpStatus.CREATED)
public void createAll(#PathVariable("purchaseId") final Long purchaseId, #RequestBody final Tag[] entities)
{
Purchase purchase = purchaseService.getById(purchaseId);
Set<Tag> tags = new HashSet<Tag>(Arrays.asList(entities));
purchase.addTags(tags);
purchaseService.updatePurchase(purchase);
}
Purchase:
#Entity
#XmlRootElement
public class Purchase implements Serializable
{
/**
*
*/
private static final long serialVersionUID = 6603477834338392140L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#OneToMany(mappedBy = "purchase", fetch = FetchType.LAZY, cascade={CascadeType.ALL})
private Set<Tag> tags;
#JsonIgnore
public Set<Tag> getTags()
{
if (tags == null)
{
tags = new LinkedHashSet<Tag>();
}
return tags;
}
public void setTags(Set<Tag> tags)
{
this.tags = tags;
}
public void addTag(Tag tag)
{
tag.setPurchase(this);
this.tags.add(tag);
}
public void addTags(Set<Tag> tags)
{
Iterator<Tag> it = tags.iterator();
while (it.hasNext())
{
Tag tag = it.next();
tag.setPurchase(this);
this.tags.add(tag);
}
}
...
}
Tag:
#Entity
#XmlRootElement
public class Tag implements Serializable
{
/**
*
*/
private static final long serialVersionUID = 5165922776051697002L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumns({#JoinColumn(name = "PURCHASEID", referencedColumnName = "ID")})
private Purchase purchase;
#JsonIgnore
public Purchase getPurchase()
{
return purchase;
}
public void setPurchase(Purchase purchase)
{
this.purchase = purchase;
}
}
PurchaseService:
#Service
public class PurchaseService implements IPurchaseService
{
#Autowired
private IPurchaseDAO purchaseDAO;
public PurchaseService()
{
}
#Transactional
public List<Purchase> getAll()
{
return purchaseDAO.findAll();
}
#Transactional
public Purchase getById(Long id)
{
return purchaseDAO.findOne(id);
}
#Transactional
public void addPurchase(Purchase purchase)
{
purchaseDAO.save(purchase);
}
#Transactional
public void updatePurchase(Purchase purchase)
{
purchaseDAO.update(purchase);
}
}
TagService:
#Service
public class TagService implements ITagService
{
#Autowired
private ITagDAO tagDAO;
public TagService()
{
}
#Transactional
public List<Tag> getAll()
{
return tagDAO.findAll();
}
#Transactional
public Tag getById(Long id)
{
return tagDAO.findOne(id);
}
#Transactional
public void addTag(Tag tag)
{
tagDAO.save(tag);
}
#Transactional
public void updateTag(Tag tag)
{
tagDAO.update(tag);
}
}
Any ideas on how I can fix this? (I want to avoid using EAGER loading).
Do I need to setup some form of session management for transactions?
Thanks
Updates based on JB suggestions
TagController
#RequestMapping(value = "purchases/{purchaseId}/tags", method = RequestMethod.POST, params = "manyTags")
#ResponseStatus(HttpStatus.CREATED)
public void createAll(#PathVariable("purchaseId") final Long purchaseId, #RequestBody final Tag[] entities)
{
Purchase purchase = purchaseService.getById(purchaseId);
// Validation
RestPreconditions.checkRequestElementNotNull(purchase);
RestPreconditions.checkRequestElementIsNumeric(purchaseId);
Set<Tag> tags = new HashSet<Tag>(Arrays.asList(entities));
purchaseService.addTagsToPurchase(purchaseId, tags);
}
PurchaseService
#Transactional
public void addTagsToPurchase(Long purchaseId, Set<Tag> tags)
{
Purchase p = purchaseDAO.findOne(purchaseId);
p.addTags(tags);
}
You load the Purchase without initializing its tags collection and then, in your controller, once the transaction is committed and the session closed, you're adding a tag to this non-initialized collection. So obviously, this exception is thrown.
You have two possibilities:
Load the tags with the Purchase, either by calling Hibernate.initialize(purchase.getTags()), or by executing a JPQL query that loads the tag along with its tags, in a single query (select distinct p from Purchase p left join fetch p.tags).
Instead of having a service class that offers noting more than the DAO, add a real service method addTagsToPurchase(Long purchaseId, Set<Tag> tags) which reloads the purchase and adds the tags to this purchase. This is in fact the service method needed by your controller.
I of course prefer the second solution by far:
it shows why a service layer is useful,
it removes business code from the presentation layer to put it in the service layer,
it's more efficient
it's safer because it uses attached entities, and thus avoids the kind of exception you're having.
In general, if your controller, to execute a single atomic action, needs several calls to the service layer, it means that the service layer doesn't offer the needed functionality, and that the service is implemented in the presentation layer instead.

org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions

Upon deleting an entity from the database I get the following exception:
org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
at org.hibernate.collection.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:410)
at org.hibernate.event.def.OnUpdateVisitor.processCollection(OnUpdateVisitor.java:43)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:101)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:61)
at org.hibernate.event.def.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:55)
at org.hibernate.event.def.AbstractVisitor.process(AbstractVisitor.java:123)
at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:101)
at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:52)
at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:767)
at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:745)
at org.springframework.orm.hibernate3.HibernateTemplate$25.doInHibernate(HibernateTemplate.java:790)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:372)
at org.springframework.orm.hibernate3.HibernateTemplate.delete(HibernateTemplate.java:784)
at org.springframework.orm.hibernate3.HibernateTemplate.delete(HibernateTemplate.java:780)
at pl.edu.agh.adam.core.projects.dao.TagDAO.delete(TagDAO.java:98)
at pl.edu.agh.adam.core.projects.ProjectService.deleteTag(ProjectService.java:109)
at pl.edu.agh.adam.core.projects.web.TagPresenter.deleteTag(TagPresenter.java:97)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.el.parser.AstValue.invoke(AstValue.java:234)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
at org.apache.myfaces.view.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:83)
at javax.faces.component._MethodExpressionToMethodBinding.invoke(_MethodExpressionToMethodBinding.java:88)
at org.apache.myfaces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:100)
at javax.faces.component.UICommand.broadcast(UICommand.java:120)
at javax.faces.component.UIData.broadcast(UIData.java:708)
at javax.faces.component.UIViewRoot._broadcastAll(UIViewRoot.java:890)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:234)
at javax.faces.component.UIViewRoot._process(UIViewRoot.java:1202)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:623)
at org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:35)
at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:143)
at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:93)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
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:852)
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:619)
I've dug deep and tried numerous solutions from the hibernate forum, but still I don't know what's going on and where the sessions are opened. The conditions under which this problem occurs:
First: OpenSessionInViewFilter - I've asked about it here. Everything seemed to work fine, but the deleting stopped all of a sudden the following day and all I've done is - I've added a non-connected class to a non-connected package.
<!-- Hibernate OpenSession Filter -->
<filter>
<filter-name>hibernateFilter</filter-name>
<filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
<init-param>
<param-name>singleSession</param-name>
<param-value>false</param-value>
</init-param>
<init-param>
<param-name>sessionFactoryBeanName</param-name>
<param-value>sessionFactory</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>hibernateFilter</filter-name>
<url-pattern>*</url-pattern>
</filter-mapping>
Second: three-tier architecture. Here are the classes and the JSF page:
#Entity
#Table(name = "tag")
public class Tag implements Serializable {
private static final long serialVersionUID = 1L;
#ManyToMany(mappedBy = "tags", targetEntity = Project.class)
List<Project> projects = new ArrayList<Project>();
#Transient
public static final String PROP_ID = "id";
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "tag_id")
private Long id;
#Transient
public static final String PROP_NAME = "name";
#Column(name = "name", length = 25, unique = true)
private String name;
}
public class TagDAO extends HibernateDaoSupport implements ITagDAO {
#Override
public void create(Tag tag) {
getHibernateTemplate().save(tag);
}
#Override
public Tag getTag(String name){
Tag group = null;
DetachedCriteria criteria = DetachedCriteria.forClass(Tag.class);
criteria.add(Restrictions.eq("name", name));
List<Tag> tags = getHibernateTemplate().findByCriteria(criteria);
if ((tags != null) && (tags.size() > 0)) {
group = (Tag)tags.get(0);
}
return group;
}
#Override
public Tag getTag(Long id){
Tag group = null;
List<Tag> groups = getHibernateTemplate().find(
"from Tag where id = ?", id);
if ((groups != null) && (groups.size() > 0)) {
group = (Tag)groups.get(0);
}
return group;
}
#Override
public List<Tag> getTags(){
List<Tag> ret = getHibernateTemplate().find("from Tag");
System.out.println("Dao got "+ret.size()+" tags");
return ret;
}
#Override
public Integer getTagCount() {
DetachedCriteria criteria = DetachedCriteria.forClass(Tag.class);
criteria.setProjection(Projections.rowCount());
return (Integer)(getHibernateTemplate().findByCriteria(criteria).get(0));
}
#Override
public void delete(Tag group) {
getHibernateTemplate().delete(group);
}
#Override
public void update(Tag group) {
getHibernateTemplate().update(group);
}
#Override
public List<Tag> getTags(Integer first, Integer resultsPerPage,
String order, Boolean asc) {
DetachedCriteria criteria = DetachedCriteria.forClass(Tag.class);
if (asc){
criteria.addOrder(Order.asc(order));
}else{
criteria.addOrder(Order.desc(order));
}
return (List<Tag>)getHibernateTemplate().findByCriteria(criteria, first, resultsPerPage);
}
}
public class ProjectService implements IProjectService {
// Beans used by this service.
private IProjectDAO projectDao;
private ITagDAO tagDao;
#Override
public void createProject(Project project) throws AlreadyExistsException {
if (projectDao.getProject(project.getName()) != null) {
throw new AlreadyExistsException();
}
projectDao.addProject(project);
}
#Override
public List<Project> getProjects(Integer first, Integer howMany, String order,
boolean asc) {
return projectDao.getProjects(first, howMany, order, asc);
}
#Override
public Integer getProjectCount(){
return projectDao.getProjectCount();
}
#Override
public List<Project> getProjects() {
return projectDao.getAllProjects();
}
#Override
public void deleteProject(Long id) {
projectDao.removeProject(id);
}
#Override
public List<Tag> getTags() {
return tagDao.getTags();
}
#Override
public Tag getTag(String name){
return tagDao.getTag(name);
}
#Override
public void createTag(Tag tag) throws AlreadyExistsException {
if (tagDao.getTag(tag.getName()) != null) {
throw new AlreadyExistsException();
}
tagDao.create(tag);
}
#Override
public void deleteTag(Long id) {
tagDao.delete(tagDao.getTag(id));
}
#Override
public void updateTag(Tag tag) {
tagDao.update(tag);
}
}
#ManagedBean(name = "tagPresenter")
#RequestScoped
public class TagPresenter {
private List<Tag> tags;
private IProjectService projectService;
private Tag tag;
public void setTag(Tag tag) {
this.tag= tag;
}
public Tag getTag() {
return tag;
}
public TagPresenter() {
projectService = (IProjectService)ServiceFinder.getInstance()
.findBean("projectService");
tags = projectService.getTags();
}
private void refresh() {
tags = projectService.getTags();
}
public List<Tag> getTags() {
refresh();
return tags;
}
public void deleteTag() {
projectService.deleteTag(tag.getId());
}
}
finally the webpage:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:p="http://primefaces.prime.com.tr/ui">
<ui:composition template="/templates/template.xhtml">
<ui:define name="head">
<title>Tags</title>
<link rel="stylesheet" type="text/css" href="#{facesContext.externalContext.requestContextPath}/styles/style.css"/>
</ui:define>
<ui:define name="content">
<h:form name="commandForm">
<p:dataTable var="tag" name="tagsList" value="${tagPresenter.tags}" paginator="true" rows="10" >
<p:column sortBy="#{tag.id}">
<f:facet name="header">
<h:outputText value="Id" />
</f:facet>
<h:outputText value="#{tag.id}" />
</p:column>
<p:column sortBy="#{tag.name}">
<f:facet name="header">
<h:outputText value="Name" />
</f:facet>
<h:outputText value="#{tag.name}" />
</p:column>
<p:column>
<h:commandLink action="#{tagDisplayer.showTag}" value="Modify">
<f:setPropertyActionListener target="#{tagDisplayer.tag}" value="#{tag}"/>
</h:commandLink>
<h:commandLink action="#{tagPresenter.deleteTag}" value="Delete">
<f:setPropertyActionListener target="#{tagPresenter.tag}" value="#{tag}"/>
</h:commandLink>
</p:column>
</p:dataTable>
</h:form>
<p:messages id="deletingError" showDetail="true"/>
</ui:define>
</ui:composition>
</html>
How is this problem caused and how can I solve it?
Fixes for this vary widely; it can be caused by problems like
bad session handling in your framework configuration
bad cascade settings, incorrect persistence settings
forgetting initialization of an Collection stored in a #ManyToOne database relation.
Make sure to check thoroughly for these cases in your mapping/hibernate configurations - before wasting hours. :D
Take a look at the HibernateTemplate chapter in the Spring documentation. Take a look at implementing a callback approach to access the session.
public void delete(final Tag group) throws Exception {
HibernateCallback callback = new HibernateCallback() {
public Object doInHibernate(Session session) throws HibernateException, SQLException {
Object groupObj = session.load(Tag.class, group.getId());
session.delete(groupObj);
return null;
}
};
getHibernateTemplate().execute(callback);
}
If the above is not what you are looking for you can still do a traditional approach as mentioned further down in the Spring documentation. In this approach don't use the HibernateTemplate to delete the object but use the Session from the HibernateDaoSupport to handle the delete.
public void delete(Tag group) throws Exception {
Session session = getSession(false);
Object groupObj = session.load(Tag.class, group.getId());
session.delete(groupObj);
}
This can be caused by calling session.disconnect() instead of session.close().

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