selectOneMenu - NullPointerException

[siobhan.ernest]

Hello -

I am trying to implement a dropdown on a form and getting a NullPointerException during the render phase:

xhtml snippet:

 <h:selectOneMenu id="selectedUploadDefinition" value="#{uploadService.selectedUploadDefinition}">
 <s:selectItems
 value="#{uploadDefinitions}"
 var="ud"
 label="#{ud.name}"
 noSelectionLabel="Please Select..."/>
 <s:convertEntity/>
 </h:selectOneMenu>

action snippet:

@Stateful
@Name("uploadService")
@Scope(ScopeType.EVENT)
@Restrict("#{identity.loggedIn}")
public class UploadAction implements Upload {

 @Logger
 Log log;

 @PersistenceContext
 private EntityManager em;

 private byte[] data;
 private String contentType;
 private String fileName;
 private int size;

 @Out(required = false)
 private List<UploadDefinition> uploadDefinitions;

 private UploadDefinition selectedUploadDefinition ;


 @Factory("uploadDefinitions")
 public void loadUploadDefinitions() {
 log.info("UPLOAD SERVICE: loading uploadDefinitions for upload action");
 uploadDefinitions = em.createQuery(
 "select ud from UploadDefinition ud order by ud.name")
 .getResultList();
 log.info("RESULT SIZE: " + uploadDefinitions.size());
 }

 public List<UploadDefinition> getUploadDefinitions() {
 return uploadDefinitions;
 }

entity :

@Entity
public class UploadDefinition implements Serializable {
 private long uoid;
 private String name ;
 private String headers ;
 private List<ImportField> importFields ;

 public UploadDefinition() {
 }

 public UploadDefinition(String name, String headers) {
 this.name = name;
 this.headers = headers;
 }

 public UploadDefinition(long uoid, String name, String headers) {
 this.uoid = uoid;
 this.name = name;
 this.headers = headers ;
 }

 @Id @GeneratedValue
 public long getUoid() {
 return uoid;
 }

 public void setUoid(long uoid) {
 this.uoid = uoid;
 }

 @Column(name = "name", unique = true)
 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }

 @Length(max=512)
 public String getHeaders() {
 return headers;
 }

 public void setHeaders(String headers) {
 this.headers = headers;
 }

 @OneToMany(mappedBy = "uploadDefinition", fetch=FetchType.EAGER)
 @OrderBy("value")
 public List<ImportField> getImportFields() {
 return importFields;
 }

 public void setImportFields(List<ImportField> importFields) {
 this.importFields = importFields;
 }
}

stacktrace:

java.lang.NullPointerException
 at org.jboss.seam.ui.converter.EntityConverterStore.getEntityManager(EntityConverterStore.java:81)
 at org.jboss.seam.ui.converter.EntityConverterStore.put(EntityConverterStore.java:60)
 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.jboss.seam.util.Reflections.invoke(Reflections.java:21)
 at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:31)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
 at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:31)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.transaction.TransactionInterceptor$1.work(TransactionInterceptor.java:38)
 at org.jboss.seam.util.Work.workInTransaction(Work.java:40)
 at org.jboss.seam.transaction.TransactionInterceptor.aroundInvoke(TransactionInterceptor.java:32)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:42)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:106)
 at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:155)
 at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:91)
 at org.jboss.seam.ui.converter.EntityConverterStore_$$_javassist_2.put(EntityConverterStore_$$_javassist_2.java)
 at org.jboss.seam.ui.converter.EntityConverter.getAsString(EntityConverter.java:67)
 at org.jboss.seam.ui.converter.PrioritizableConverter.getAsString(PrioritizableConverter.java:67)
 at org.jboss.seam.ui.converter.ConverterChain.getAsString(ConverterChain.java:123)
 at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:469)
 at com.sun.faces.renderkit.html_basic.MenuRenderer.renderOption(MenuRenderer.java:502)
 at com.sun.faces.renderkit.html_basic.MenuRenderer.renderOptions(MenuRenderer.java:757)
 at com.sun.faces.renderkit.html_basic.MenuRenderer.renderSelect(MenuRenderer.java:811)
 at com.sun.faces.renderkit.html_basic.MenuRenderer.encodeEnd(MenuRenderer.java:335)
 at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:836)
 at org.jboss.seam.ui.util.cdk.RendererBase.renderChild(RendererBase.java:190)
 at org.jboss.seam.ui.util.cdk.RendererBase.renderChildren(RendererBase.java:166)
 at org.jboss.seam.ui.renderkit.ValidateAllRendererBase.doEncodeChildren(ValidateAllRendererBase.java:33)
 at org.jboss.seam.ui.util.cdk.RendererBase.encodeChildren(RendererBase.java:92)
 at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:812)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:886)
 at javax.faces.render.Renderer.encodeChildren(Renderer.java:137)
 at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:812)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:886)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:892)
 at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
 at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
 at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:216)
 at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:106)
 at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
 at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:144)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
 at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:85)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:44)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
 at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
 at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:60)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.jboss.seam.debug.hot.HotDeployFilter.doFilter(HotDeployFilter.java:68)
 at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
 at java.lang.Thread.run(Thread.java:619)

Using Seam 2.0.0GA and JBoss 4.2.2GA

Any ideas what I am doing wrong?

[pmuir]

Post your components.xml - you need to use a SMPC with s:convertEntity

[chrismalan]

I don't know if I have a Seam Managed Persistence Context in my components.xml. I'm mailing this from work. But I at last did get s:selectItems to work.

What did the trick was that every @entity that is used as a source for s:selectItems must implement a "boolean equals(Object obj)" and an "int hashCode()" method. Make sure about this last one, maybe it's getHashCode or something similar.

Give it a go.

[andygibson]

Pete, since he is using @PersistenceContext, doesn't that rule out the possibility of using an SMPC?

This PC is only scoped to the event, after which it is unavailable. I've been having a null filled list problem recently and I think (haven't had time to check) that it is tied to the PC flushing and invalidating objects (based on my late night reading of JPA with Hibernate).

[siobhan.ernest]

Hi all -

I actually scrapped this code and changed it to the following:

components.xml

<persistence:managed-persistence-context name="entityManager"
 auto-create="true"
 persistence-unit-jndi-name="java:/rte_trackerEntityManagerFactory"/>

plus a list seam-gen generated list bean:

@Name("uploadDefinitionList")
public class UploadDefinitionList extends EntityQuery {

 private static final String[] RESTRICTIONS = {
 "lower(uploadDefinition.name) like concat(lower(#{uploadDefinitionList.uploadDefinition.name}),'%')",
 "lower(uploadDefinition.headers) like concat(lower(#{uploadDefinitionList.uploadDefinition.headers}),'%')",
 "lower(uploadDefinition.matchOn) like concat(lower(#{uploadDefinitionList.uploadDefinition.matchOn}),'%')",
 "lower(uploadDefinition.uploadType) like concat(lower(#{uploadDefinitionList.uploadDefinition.uploadType}),'%')",};

 private UploadDefinition uploadDefinition = new UploadDefinition();

 @Override
 public String getEjbql() {
 return "select uploadDefinition from UploadDefinition uploadDefinition";
 }

 @Override
 public Integer getMaxResults() {
 return 25;
 }

 public UploadDefinition getUploadDefinition() {
 return uploadDefinition;
 }

 @Override
 public List<String> getRestrictions() {
 return Arrays.asList(RESTRICTIONS);
 }

}

The upload action:

public abstract class EntityUploadAction {
 @Logger
 Log log;

 @PersistenceContext
 protected EntityManager entityManager;

 @In
 protected FacesMessages facesMessages;


 <snip>


 protected UploadDefinition selectedUploadDefinition;


 <snip>

 public UploadDefinition getSelectedUploadDefinition() {
 return selectedUploadDefinition;
 }

 public void setSelectedUploadDefinition(UploadDefinition selectedUploadDefinition) {
 this.selectedUploadDefinition = selectedUploadDefinition;
 }

 <snip>
}

The upload action is used more than once, so this is extended in other actions.

And finally, the .xhtml

<s:decorate id="selectedUploadDefinitionnDecoration" template="layout/edit.xhtml">
 <ui:define name="label">Upload Definition</ui:define>
 <h:selectOneMenu value="#{studentUploadService.selectedUploadDefinition}" required="true"
 id="selectedUploadDefinition">
 <s:selectItems value="#{uploadDefinitionList}" var="ud" label="#{ud.name}"
 noSelectionLabel="Please Select..."/>
 <s:convertEntity/>
 </h:selectOneMenu>
 </s:decorate>

It all works, and I am happy - just posting this for anyone who might be interested.