java.lang.ClassCastException: java.util.ArrayList

[Dinesh]

Hi all,

I've gotta problem regarding entity beans.

I have a simple entity bean as follows:

Remote:
package test;

import javax.ejb.EJBObject;
import java.rmi.RemoteException;
import java.io.Serializable;

public interface TestEntity extends EJBObject, Cloneable, Serializable
{
}

EJB:
package test;

import java.util.Vector;
import javax.ejb.*;
import javax.naming.*;
import javax.rmi.PortableRemoteObject;

public class TestEntityEJB implements EntityBean
{
   public String name;
   private EntityContext context;

   public String ejbCreate(String n) throws CreateException
   {
       return "";
   }


//----------------------------------------------------------------------

   public void setEntityContext(EntityContext context)
   {  this.context = context;
      try {
         makeConnection();
      } catch (Exception ex) {
          throw new EJBException("Unable to connect to database. " +
             ex.getMessage());
      }
   }


//----------------------------------------------------------------------

   public void unsetEntityContext()
   {
   }


//----------------------------------------------------------------------

   public void ejbPostCreate(String n)
   {
   }

//----------------------------------------------------------------------

   public void ejbRemove()
   {  try
      {  deleteRow ("");
      }
      catch (Exception ex)
      {  throw new EJBException("ejbRemove: " + ex.getMessage());

      }
   }

   public void remove()
   {  try
      {  deleteRow ("");
      }
      catch (Exception ex)
      {  throw new EJBException("ejbRemove: " + ex.getMessage());

      }
   }

//----------------------------------------------------------------------

   public void ejbActivate()
   {  name = (String)context.getPrimaryKey();
   }

//----------------------------------------------------------------------

   public void ejbPassivate()
   {  name = null;
      /*productID = null;
      productName = null;*/
   }

//----------------------------------------------------------------------

   public void ejbLoad()
   {  try
      {  loadRow();
      }
      catch (Exception ex)
      {  throw new EJBException("ejbLoad: " + ex.getMessage());
      }
   }

//----------------------------------------------------------------------

   public void ejbStore()
   {  try
      {  storeRow();
      }
      catch (Exception ex)
      {  throw new EJBException("ejbLoad: " +
         ex.getMessage());
      }
   }

//==========================================================================
====

   public String ejbFindByPrimaryKey(String primaryKey) throws
FinderException
   {  boolean result;
      try
      {  result = selectByPrimaryKey(primaryKey);
      }
      catch (Exception ex)
      {  throw new EJBException("ejbFindByPrimaryKey: " + ex.getMessage());
      }

      if (result)
      {  return primaryKey;
      }
      else
      {  throw new ObjectNotFoundException ("Row for id " + primaryKey + "
not found.");
      }
   }

   public Vector ejbFindAll() throws FinderException
   {  Vector result;

      try
      { result = selectAll ();

      }
      catch (Exception ex)
      {  throw new EJBException("ejbFindAll " + ex.getMessage());
      }

      if (result.size()==0)
      {  throw new ObjectNotFoundException("No rows found.");
      }
      else
      {  return result;
      }
   }

//==========================================================================
====

   private boolean selectByPrimaryKey(String primaryKey)
   {  return true;
   }

   private Vector selectAll ()
   {  Vector v = new Vector ();
      v.addElement("element");
      return v;
   }


//==========================================================================
====

   private void makeConnection() throws NamingException
   {
      try
      {  Context initial = new InitialContext();

     }
     catch (Exception ex)
     {  System.err.println("Caught an unexpected exception!");
        ex.printStackTrace();
     }
   }

   private void loadRow()
   {
   }

   private void insertRow(String n)
   {
   }

   private void deleteRow (String id)
   {
   }

   private void storeRow ()
   {
   }
}

Home:
package test;

import java.util.Vector;
import java.rmi.RemoteException;
import javax.ejb.*;

public interface TestEntityHome extends EJBHome
{  public TestEntity create (String n)
   throws RemoteException, CreateException;

   public TestEntity findByPrimaryKey (String name)
   throws FinderException, RemoteException;

   public Vector findAll ()
   throws FinderException, RemoteException;

}

All my finder method findall () in the home does is return a Vector which
contains a single String object "element".

I test this finder method with client code:

      try
      {  Context initial = new InitialContext();
         Object objref = initial.lookup("TestEntity");

         TestEntityHome home =
(TestEntityHome)PortableRemoteObject.narrow(objref, TestEntityHome.class);

         Vector v = home.findAll ();

      }
      catch (Exception ex)
      {  throw new EJBException(ex.getMessage());
      }

the code Vector v = home.findAll (); causes the catch block to be executed

and I get the following exception:
javax.ejb.EJBException: RemoteException occurred in server thread; nested
exception is:
        java.rmi.RemoteException: Unknown Exception/Error thrown by EJB method.;
nested exception is:
        java.lang.ClassCastException: java.util.ArrayList
            at test.TestClient.findTestEntities(TestClient.java:148)
            at test.TestClient.testTestEntity(TestClient.java:54)
            at test.TestClient.<init>(TestClient.java:23)
            at test.TestClient.main(TestClient.java:28)
Exception in thread "main"


java.lang.ClassCastException: java.util.ArrayList       - does this mean that I
can't use Vectors in the returns of finder methods???

Your comments will be greatly appreciated.

Regards,

Dinesh.

===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST".  For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".