Create an entity bean with CMP

[tbaud72]

I would like to retrieve an entity bean with a finder method.

i tried my own method (findLast) and findByPrimaryKey but
in the two cases Jboss seems to meet problems for
creating the bean (java.lang.NullPointerException in org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.createBeanClassInstance).

All my beans are deployed (see with jmx-console) and i
don't understant why it can't create one bean.

Thanks.

[cvandyck]

Can you post some of your bean definition code?

[tbaud72]

yes, surely.
i developed beans with xdoclet for generating interfaces
and DD.


* @xdoclet-generated at 31 déc. 02 15:20:00
*/
public interface SaisonLocalHome extends javax.ejb.EJBLocalHome
{
public static final String COMP_NAME="java:comp/env/ejb/Saison";
public static final String JNDI_NAME="orvault/entity/SaisonLocal";

/**
* Create a new saison
*/
public orvault.interfaces.SaisonLocal create(java.lang.Integer newid,java.lang.String newlibelle) throws javax.ejb.CreateException;

public orvault.interfaces.SaisonLocal findByPrimaryKey(java.lang.Integer pk) throws javax.ejb.FinderException;
public orvault.interfaces.SaisonLocal findCurrent() throws javax.ejb.FinderException;
public orvault.interfaces.SaisonLocal findLast() throws javax.ejb.FinderException;
public java.util.Collection findAll() throws javax.ejb.FinderException;

}


/**
* Local interface for Saison.
* @author XDOCLET 1.1.2
* @xdoclet-generated at 31 déc. 02 15:20:00
*/
public interface SaisonLocal extends javax.ejb.EJBLocalObject
{
/**
* Saison Cours
*/
public java.lang.Integer getCours( ) ;

/**
* Saison id
*/
public java.lang.Integer getId( ) ;

/**
* Saison libelle
*/
public java.lang.String getLibelle( ) ;

/**
* Saison Cours
*/
public void setCours( java.lang.Integer cours ) ;

/**
* Saison libelle
*/
public void setLibelle( java.lang.String lib ) ;

}


implementation bean.

/**
* This is a saison bean.
* @author Thierry BAUDOUIN
*
* @ejb:bean name="Saison"
type="CMP" cmp-version="2.x" view-type="local"
jndi-name="orvault/entity/Saison" local-jndi-name="orvault/entity/SaisonLocal"
primkey-field="id"
* @ejb:finder signature="orvault.interfaces.SaisonLocal findCurrent()"
unchecked="true" transaction-type="Supports"
query="SELECT DISTINCT OBJECT(D) FROM Saison AS d WHERE d.B_COURS = 1"
* @ejb:finder signature="orvault.interfaces.SaisonLocal findLast()"
unchecked="true" transaction-type="Supports"
query="SELECT DISTINCT OBJECT(D) FROM Saison AS d WHERE d.N_CODESAIS in ( SELECT MAX(N_CODESAIS) from Saison )"
* @ejb:finder signature="java.util.Collection findAll()" unchecked="true" transaction-type="NotSupported"
* @ejb:home remote-class="orvault.interfaces.SaisonHome" local-class="orvault.interfaces.SaisonLocalHome"
* @ejb:interface remote-class="orvault.interfaces.Saison" local-class="orvault.interfaces.SaisonLocal"
* @ejb:pk class="java.lang.Integer" generate="false" unchecked="true"
* @ejb:data-object package="orvault.interfaces"
*
* @jboss:table-name "saison"
* @jboss:tuned-updates "true"
*/
public abstract class SaisonBean implements javax.ejb.EntityBean{

// Public -------------------------------------------------------------------

/**
* Saison id
* @ejb:pk-field
* @ejb:interface-method
* @ejb:persistent-field
* @jboss:column-name "N_CODESAIS"
*/
public abstract Integer getId();

/** Saison id (not remote) */
public abstract void setId(Integer id);

/**
* Saison libelle
* @ejb:interface-method
* @ejb:persistent-field
* @jboss:column-name "C_LIBELLESAIS"
*/
public abstract String getLibelle();

/**
* Saison libelle
* @ejb:interface-method
*/
public abstract void setLibelle(String lib);

/**
* Saison Cours
* @ejb:interface-method
* @ejb:persistent-field
* @jboss:column-name "B_COURS"
*/
public abstract Integer getCours();

/**
* Saison Cours
* @ejb:interface-method
*/
public abstract void setCours(Integer cours);



// Implementation of EntityBean ---------------------------------------------

/**
* Create a new saison
* @ejb:create-method
*/
public Integer ejbCreate(Integer newid, String newlibelle) throws javax.ejb.CreateException{
setLibelle(newlibelle);
setId(newid);
setCours(new Integer(0));
return newid;
}

/** Create a new saison */
public void ejbPostCreate(Integer newid, String newlibelle) throws javax.ejb.CreateException{

}

/**
* Remove this saison
* @ejb:transaction type="Mandatory"
*/
public void ejbRemove() throws javax.ejb.RemoveException, javax.ejb.EJBException {}
}


I use this entity bean inside a session bean like this :

public class AdminManager implements javax.ejb.SessionBean{

// Attributes ---------------------------------------------------------------

//Runtime contexts...
private SessionContext sctx = null;
private transient InitialContext ctx = null;

//EJB references...
private SaisonLocalHome saisonhome = null;

//Environment entries...
private String datasource = null;


// Public -------------------------------------------------------------------

/**
* Create a new Saison
* @ejb:interface-method view-type="both"
* @ejb:transaction type="Required"
*/
public void createSaison(String newsaison ) throws EJBException{
try{
//Retrieve homes if null.
System.out.println ("Debut create saison");
if (saisonhome == null) saisonhome = (SaisonLocalHome)ctx.lookup("java:comp/env/ejb/Saison");
System.out.println ("saison home " + saisonhome.toString());
//Create the new saison
SaisonLocal maxsaison = saisonhome.findByPrimaryKey(new Integer(1));
System.out.println ("saison home max " + maxsaison.toString());
SaisonLocal newsaisoncreated = saisonhome.create(new Integer(maxsaison.getId().intValue() + 1), newsaison);
}
catch (Exception e) {throw new EJBException(e);}
}


i have the error (see first message) when it execute saisonhome.findByPrimaryKey(new Integer(1));. my variable "saisonhome" is good value.

thanks for your help.

[cvandyck]

Well, one thing I have noticed in my beans is that when I write my EJB-QL, I have to write my field references with the bean-derived name of the field.

In other words, if I have a getName and setName pair that relate to CMP fields, then in my EJB-QL, I would write something like

query="SELECT OBJECT(c) from Data AS c WHERE c.name = ?1"

Even if I had specified that my column persistence name was something like "objectName". That caused me grief for about two days.

Also, I'm not sure if EJB-QL is case sensitive, but if so, you've got some case mismatches in there.

I hope that helps,
Collin