Cast Problem I dont understand ... Converter / SelectItems

[paper]

I tried to merge a Converter and a List to have one flexible component to use for different Entity-Classes to be used in a JSF-Select. I no get populated the List once, but abfter I get te following Exception:

22:23:04,392 ERROR [[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
java.lang.ClassCastException: java.util.ArrayList
 at javax.faces.component.UIOutput.restoreState(UIOutput.java:92)
 at javax.faces.component.UIInput.restoreState(UIInput.java:384)
 at javax.faces.component.html.HtmlSelectOneMenu.restoreState(HtmlSelectOneMenu.java:406)
 at javax.faces.component.UIComponentBase.processRestoreState(UIComponentBase.java:511)
 at javax.faces.component.UIComponentBase.processRestoreState(UIComponentBase.java:502)
 at javax.faces.component.UIComponentBase.processRestoreState(UIComponentBase.java:502)
 at org.apache.myfaces.application.jsp.JspStateManagerImpl.restoreComponentState(JspStateManagerImpl.java:129)
 at org.apache.myfaces.application.jsp.JspStateManagerImpl.restoreView(JspStateManagerImpl.java:185)
 at org.jboss.seam.jsf.SeamPhaseListener$StateManagerInterceptor.restoreView(SeamPhaseListener.java:205)
 at org.apache.myfaces.application.jsp.JspViewHandlerImpl.restoreView(JspViewHandlerImpl.java:255)
 at com.sun.facelets.FaceletViewHandler.restoreView(FaceletViewHandler.java:319)
 at org.apache.myfaces.lifecycle.LifecycleImpl.restoreView(LifecycleImpl.java:124)
 at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:66)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:106)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:23)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
 at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:54)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:174)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:868)
 at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:663)
 at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
 at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
 at java.lang.Thread.run(Thread.java:595)

I've the following Code:

package org.termtimer.controller;

import static org.jboss.seam.InterceptionType.ALWAYS;
import static org.jboss.seam.ScopeType.CONVERSATION;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import javax.ejb.Interceptors;
import javax.ejb.Remove;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.ConverterException;
import javax.faces.model.SelectItem;

import org.jboss.logging.Logger;
import org.jboss.seam.annotations.Create;
import org.jboss.seam.annotations.Destroy;
import org.jboss.seam.annotations.Intercept;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.ejb.SeamInterceptor;
import org.termtimer.model.Lookup;


@Scope(CONVERSATION)
@Name("flexSelectItems")
@Interceptors(SeamInterceptor.class)
@Intercept (ALWAYS)
public class FlexSelectItemsBean extends LinkedList<SelectItem>
 implements List<SelectItem>, javax.faces.convert.Converter{

 private static final long serialVersionUID = -1611564525004318869L;
 private static final Logger log = Logger.getLogger(FlexSelectItemsBean.class);
 private Map<String, Object> items;

 public FlexSelectItemsBean() {
 super();
 items = new HashMap<String, Object>();
 log.info("SelectItemArrayList(c) called"+this);
 }

 public FlexSelectItemsBean(Collection<SelectItem> c) {
 super(c);
 items = new HashMap<String, Object>();
 log.info("SelectItemArrayList(c) called"+this);
 }

 public void convertIn(List list) {
 log.info("convertIn() called"+this);
 Iterator i = list.iterator();
 this.clear();
 while(i.hasNext()){
 log.info("outer while");
 Object o = i.next();
 try{
 log.info("inner while");
 Lookup l = (Lookup) o;
 SelectItem item = new SelectItem(o, l.getShowName());
 items.put(l.getKey(), o);
 this.add(item);

 }catch(Exception E){
 log.info("Exception");
 }
 }
 log.info("size:"+this.size());

 }

 @Create
 public void create(){
 log.info("create() called"+this);
 }

 @Destroy @Remove
 public void destroy() {
 log.info("destroy() called"+this);
 }

 //Converter Methods
 public Object getAsObject(FacesContext arg0, UIComponent arg1, String str) throws ConverterException {
 log.info("getAsObject() called"+this);
 if(items.containsKey(str)){
 return items.get(str);
 }
 return null;
 }

 public String getAsString(FacesContext arg0, UIComponent arg1, Object obj) throws ConverterException {
 log.info("getAsString() called"+this);
 if(obj instanceof Lookup){
 Lookup l = (Lookup)obj;
 log.info("ausgabe: "+l.getKey()+" "+l.getShowName());
 return l.getKey();
 }
 return null;
 }
}

In the SFSB which controls the view, I inject the "flexSelectItems", fill it an outject it.

@In(value="flexSelectItems" ,create=true)
@Out
public FlexSelectItemsBean flexSelectItems;

flexSelectItems.convertIn(facultyAPI.getAll());

<div class="input">
 <h:selectOneMenu id="facult" value="lecturer.faculty" converter="#{flexSelectItems}">
 <f:selectItems value="#{flexSelectItems}" />
 </h:selectOneMenu>
 </div>

I see that this is a strange concept, but I'd like to know where the Problem lies. Tried a lot and am thankful fur any help.

Dennis

[gavin.king]

Um, I guess this is not a Seam-related problem, right?

[paper]

I think so, the exception occurs in a jsf component, but I m not sure. Will try again tomorrow. Its late now in Germany.

Thx
Dennis

[paper]

didn't work like that. I use now a concept simular to the lookup converter you ca find in this post:
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=71182

For all who are looking fon such a solution ill post my code here.

Dennis

The Lookup Base Class, with a static method to convert Lists with Objects that implement Lookup to Select items:

@Name("LookupConverter")
@Intercept(InterceptionType.ALWAYS)
public abstract class LookupConverter<T extends Lookup>
implements javax.faces.convert.Converter
{
 private Class<T> entityClass ;

 public LookupConverter (Class<T> entityClass)
 {
 this.entityClass = entityClass ;
 }

 public String getAsString (FacesContext context, UIComponent component, Object object)
 {
 if (object == null)
 return null ;

 T lookup = (T) object ;
 return lookup.getKey () ;
 }

 public Object getAsObject (FacesContext context, UIComponent component, String value) throws ConverterException{
 EntityManager termtimerData = (EntityManager)Component.getInstance("termtimerEM", true);
 Object o = (Object)(T) termtimerData.find(entityClass, value);
 return o;
 }

 public static List<SelectItem> convertIn(List<? extends Lookup> list) {
 Iterator i = list.iterator();
 List<SelectItem> selectlist = new LinkedList<SelectItem>();
 while(i.hasNext()){
 Object o = i.next();
 try{
 Lookup l = (Lookup) o;
 SelectItem item = new SelectItem(o, l.getShowName(), l.getKey());
 selectlist.add(item);

 }catch(Exception E){
 }
 }
 return selectlist;
 }

}

The Lookup Interface:

public interface Lookup {
 public String getShowName () ;
 public String getKey () ;
}

A concrete Converter for an Entity Class:

@Name("FacultyConverter")
@Scope(ScopeType.APPLICATION)
@Intercept(InterceptionType.ALWAYS)
public class FacultyConverter
extends LookupConverter<Faculty>
{

 public FacultyConverter ()
 {
 super (Faculty.class) ;
 }

}

In the BakingBean:

@Out(scope=CONVERSATION)
private List<SelectItem> facultySelect;

//in the create method
facultySelect = LookupConverter.convertIn(facultyDAO.getAll());

and finaly the part in the facelet:

<h:selectOneListbox id="faculty" value="#{lecturer.faculty}" converter="#{FacultyConverter}">
 <f:selectItems value="#{facultySelect}" />
</h:selectOneListbox>

and its improtant to implement toString() and equals(Object o) in all entities.

[c_eric_ray]

where and how is "termtimerEM" defined?

[perwik]

"paper" wrote:

The Lookup Interface:

public interface Lookup {
 public String getShowName () ;
 public String getKey () ;
}

I think a better solution would be to use annotations for these two properties, like @SelectItemName and @SelectItemKey. And if @SelectItemKey is missing from the entity the default action could be to use toString() on the @Id property.