hibernate - Object is not an indexed entity or a subclass of an indexed entity -

i doing web app hibernate, hibernate search, lucene , tapestry. now, ok, until have deployed part of code app. keep getting error

render queue error in setuprender[index:layout.listarticles.grid]: failure reading parameter 'source' of component index:layout.listarticles.grid: java.lang.object not indexed entity or subclass of indexed entity 

even though have denoted article class @indexed annotation specified. may cause issue? may inherited classes cause issue, since article top of many other subclasses, , hs or lucene can't provide polymorhic search or what? stuck on half hour now. appreciated. in advance.

public class listarticles {       @property     @suppresswarnings("unused")     private article article;     @inject     private session hibernate;     @sessionstate // changed applicationstate     @property     private user user;     @property     private boolean ifuserexists;      private static logger logger = logger.getlogger(listarticles.class);     @inject     private hibernatesessionmanager hibernatesessionmanager;     @property     @persist(persistenceconstants.flash)     private string searchtext;      /**      *       *      * @return list      */     @commitafter     @suppresswarnings("unchecked")     public list<article> getarticles() {          if (article != null) {              return hibernate.createcriteria(article.class).list();         } else if (searchtext != null && searchtext.trim().length() > 0) {             fulltextsession fulltextsession = search.getfulltextsession(hibernatesessionmanager.getsession());             try {                 fulltextsession.createindexer().startandwait();             } catch (java.lang.interruptedexception e) {                 logger.warn("lucene indexing interrupted " + e);             }              querybuilder qb = fulltextsession.getsearchfactory().buildquerybuilder().forentity(article.class).get();             org.apache.lucene.search.query lucenequery = qb                     .keyword()                     .onfields("name, desc")                     .matching(searchtext)                     .createquery();              return fulltextsession.createfulltextquery(lucenequery, article.class).list();         } else {             // default - unfiltered - entitites list              return hibernate.createcriteria(article.class).list();          }     }      // 1520 lines of code trimmed using built-in plugin codetrimmer 

my listarticles.tml file looks following

<postdisplay xmlns:t="http://tapestry.apache.org/schema/tapestry_5_3.xsd" xmlns:p="tapestry:parameter">         <p>${message:newestarticles}</p>          <form t:type="form" t:id="searchform">                 <input t:type="textfield" t:id="searchtext" size="30" value="searchtext" />                     <t:submit t:id="search" value="search" /><t:submit t:id="clear" value="clear/show all" />                </form>         <t:grid source="articles" row="article" include="name, desc" >         <p:namecell>${article.name}</p:namecell>         <p:descriptioncell>${article.desc}</p:descriptioncell>          <p:empty>            <p>no articles found!</p>          </p:empty>       </t:grid>     </postdisplay> 

and article.java class looks like

    @entity     @table(name="article")     @inheritance(strategy = inheritancetype.single_table)     @discriminatorcolumn(name="art_type",discriminatortype = discriminatortype.string)     @indexed(index="indexes/essays")     public abstract class article     {     @id @generatedvalue(strategy=generationtype.identity)     @basic(optional = false)     @column(name = "art_id")     @documentid     private long id;      @basic(optional = false)     @column(name = "art_name")     @field     private string name;       @basic(optional = true)     @column(name = "art_desc")     @field     private string desc;      @basic(optional = true)     @column(name = "art_image")     @field     private string image;      @basic(optional = true)     @column(name = "art_type")     @field     private string articletype; // hard-coded, make more pro      @basic(optional = true)     @column(name = "art_subtype")     @field     private string articlesubtype; // hard-coded, make more pro      //to change or not change ...     @onetomany(mappedby = "article", cascade={cascadetype.all})     private collection<picture> collectionofpictures;       @onetomany(mappedby = "article")     private collection<starrates> collectionofstarrates;        //148 lines of code trimmed using built-in plugin codetrimmer