CRUD Hibernate Strut2 2 tablet join

I 'm trying to make a crud in Strud2 with hibernate and I can not combine two tables. Can you help me
Table 1 is Trama

@Entity
@Table(name="trama", catalog="bd_1")

public class Trama  implements java.io.Serializable {

     private int traNoca;         //Int
     private int catNoca;       //Enlace con categoria
     private String tradat;       //Dato sin importancia

    public Trama() {}

    public Trama(int traNoca, int catNoca, String tradat)
    {this.traNoca = traNoca;  this.catNoca = catNoca;  this.tradat = tradat;  }

     @Id
    @Column(name="tra_noca", nullable=false)
     public int getTraNoca() {return this.traNoca;} ES
    public void setTraNoca(int traNoca) {this.traNoca = traNoca; }

    @Column(name="cat_noca", nullable=false)
    public int getCatNoca() {return this.catNoca;}
    public void setCatNoca(int catNoca) {this.catNoca = catNoca;}

    @Column(name="tra_dat", nullable=false, length=45)
    public String getTradat() {return this.tradat;}
    public void setTradat(String tradat) { this.tradat = tradat;  }
}


This is His mapping

<hibernate-mapping>
    <class name="entidad.Trama" table="trama" catalog="bd_1">
        <id name="TraNoca" type="int">
            <column name="tra_noca" />
           <generator class="assigned"></generator>
        </id>
        <property  name="CatNoca" type="int">
            <column name="cat_noca" />
         </property>
        <property name="Tradat" type="string">
            <column name="cat_dat" length="50" />
        </property>
    </class>
</hibernate-mapping>

Categoria is 2 Table is which is the main

package entidad;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "trama", catalog = "bd_1"   )

public class Categoria  implements java.io.Serializable {

     private int catNoca;
     private String catNom;

    public Categoria() {}

    public Categoria(int catNoca, String catNom)
    {this.catNoca = catNoca;   this.catNom = catNom;}

     @Id
     @Column(name="cat_noca", nullable=false)
    public int getCatNoca() {return this.catNoca;}
    public void setCatNoca(int catNoca) {this.catNoca = catNoca;}

    @Column(name="cat_nom", nullable=false, length=45)
    public String getCatNom() {return this.catNom;}
    public void setCatNom(String catNom) { this.catNom = catNom; }
}
This is His mapping

<hibernate-mapping>
    <class name="entidad.Categoria" table="categoria" catalog="bd_1">
        <id name="CatNoca" type="int">
            <column name="cat_noca" />
           <generator class="assigned"></generator>
        </id>
        <property name="CatNom" type="string">
            <column name="cat_nom" length="50" />
        </property>
    </class>
</hibernate-mapping>
Strut2
Which sends the order

    public  void detalle2(String noca,T entity) {

        Session session = HibernateUtil.getSessionFactory().openSession();
        Transaction beginTransaction = session.beginTransaction();
        session.createSQLQuery("select c.CatNoca, c.CatNom, t.CatNoca, t.TraNoca, t.CatNom, t.tradat  from Trama t INNER JOIN Categoria c ON t.CatNoca="+entity);
        beginTransaction.commit();
        session.close();
    }



package acciones;

import static com.opensymphony.xwork2.Action.INPUT;
import static com.opensymphony.xwork2.Action.SUCCESS;
import com.opensymphony.xwork2.ActionSupport;
import entidad.Categoria;
import java.util.List;
import servicio.ServicioCategoria;

public class CategoriaAction extends ActionSupport {

    private ServicioCategoria sc= new ServicioCategoria();
    private List<Categoria> lstCat;
    private Categoria cat;
    private String m;
    private String i;
    private Integer noca;

    @Override
    public String input() throws Exception {
        if (getNoca()!=null) {setCat(sc.find(noca));}
        return INPUT;}

    public String detalle2() throws Exception {
        if (getNoca()!=null) {setCat(sc.find(noca)); }
       return INPUT;}

    @Override
    public String execute() throws Exception {return SUCCESS;}
    public String save() {    sc.save(getCat());     return "ok"; }
    public String remove(){    sc.remove(getNoca());    return "ok";    }
    public String list() throws Exception { lstCat=sc.findAll();  return execute();}
    public String search() throws Exception { lstCat = sc.search(m);return execute();}
    public String indice() throws Exception { lstCat = sc.search(i);return execute();}



    //<editor-fold defaultstate="collapsed" desc="Getter y Setter">
    public ServicioCategoria getSc() {return sc; }
    public void setSc(ServicioCategoria sc) {this.sc = sc;}
    public String getM() { return m;}
    public void setM(String m) {   this.m = m; }
    public String getI() { return i; }
    public void setI(String i) { this.i = i;}
    public Integer getNoca() { return noca; }
    public void setNoca(Integer noca) {this.noca = noca;}
    public Categoria getCat() {return cat;}
    public void setCat(Categoria cat) { this.cat = cat; }
    public List<Categoria> getLstCat() {return lstCat;}
    public void setLstCat(List<Categoria> lstCat) {this.lstCat = lstCat;}
//</editor-fold>
}
ServicioCategoria.java
public class ServicioCategoria extends AbstractFacade<Categoria> {
    public ServicioCategoria() {super(Categoria.class);}


    //CATEGORIA

    public List<Categoria> findAll() {return super.findAll();}
    public void save(Categoria cat) {super.createEdit(cat);}
    public void remove(int noca) {
        final Categoria find = super.find(noca);
        if (find!=null){
        super.remove(find);}
    }
    public Categoria find (int noca) {
        return super.find(noca);
    }

    //TRAMA
}
The JSP SAMPLE ONLY data table category
No I Get to join the tables I'm desperate

<%@ taglib prefix="s" uri="/struts-tags" %>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <br/>
        <h2>Mopstrar Datos</h2>
        <s:iterator>
        <s:form action="categoriaDetalle2">
            <s:label label="Nombre" name="cat.catNoca" />
            <s:label label="Nombre" name="cat.catNom" />
            <s:label label="La 2 tabla" />
             <s:label label="Nombre de trama" name="tra.Tradat" />
            <s:label label="Nombre de trama" name="tra.catNom" />
        </s:form>
        </s:iterator>

    </body>
</html>



I Get to join the tables I'm desperate