ClassCastException during getCursor with Oracle...

[daorriss]

Subject says it all... What am I doing wrong here? Apparently the WrappedCallableStatement implementation that JBoss uses is doing something to prevent the casting, but what do I do to get around that?

connection = getConnection("OracleDS");

 logger.finer("Calling request_list.get_default_request_list");

 cst = connection.prepareCall("{call request_list.get_default_request_list (?,?,?)}");
 cst.setInt(1, 1);
 cst.setInt(2, 1);
 cst.registerOutParameter(3, OracleTypes.CURSOR);
 cst.execute();

 rs = ((OracleCallableStatement)cst).getCursor(3);

And getConnection is implemented as:

private java.sql.Connection getConnection (String resourceName)
 throws NamingException, SQLException {

 logger.finer("Obtaining JNDI context.");
 //Obtain the JDNI context
 Context context = new InitialContext();

 logger.finer("JNDI Lookup to get the resource manager connection factory reference");
 //JNDI Lookup to get the resource manager connection factory reference
 javax.sql.DataSource ds = (javax.sql.DataSource) context.lookup("java:/jdbc/" + resourceName);

 logger.finer("Invoke factory to obtain a connection and return connection to calling environment");
 //Invoke factory to obtain a connection and return connection to calling
 //environment
 return ds.getConnection();
 }

[daorriss]

I figured out how to do it.. For posterity I'll post it here...

 cst = connection.prepareCall("{call request_list.get_default_request_list (?,?,?)}");
 cst.setInt(1, 1);
 cst.setInt(2, 1);
 cst.registerOutParameter(3, OracleTypes.CURSOR);
 cst.execute();

 rs = (ResultSet) cst.getObject(3);

Note that using getCursor doesn't work BUT getObject does provided I tell the output parameter it's a oracle cursor.

Go figure - the one thing I didn't try was the way to fix it..

The reason for this is that JBoss called statements are implemented via a WrappedCallableStatement (a JBoss object) and that can't be cast to the OracleCallableStatement (which makes sense after I thought about it a bit). However, you can register the output parameter as an oracle type and then cast *that* to the result set.

[berdaimo]

Hi !

I got the same probleme, Could you like plz to help me !

I got the following expetion :
java.lang.ClassCastException: $Proxy4 while executing the line :

rs = (ResultSet) myCallableStatement.getObject(2);


It's seems that the connexion that I retrived from the datasource of Jboss descriptor is a proxy ! on the other side when I use the classic connection using :
conn = DriverManager.getConnection(url)
I have no problem ! but I'm constrained tu use the datasource connection

Thank you

Adil

[peterj]

Are you attempting to access a data source from a standalone client? If so, see http://wiki.jboss.org/wiki/Wiki.jsp?page=HowCanIAccessADataSourceFromAClient

[berdaimo]

it's not recommended but it's possible under jboss 4 I think !
Is there any solution to get a connection from xxx-ds.xml descriptor ? have you any example using EJB to get this connection from remote Interface ?

Thank you ;)