Database connection in CMP

[Surendra]

Hi,     I want to execute a query in CMP(my requirement). I wrote following method   private DataSource dataSource = null; private Connection getConnection() throws EJBException, SQLException {        if (dataSource == null) {       //Finds DataSource from JNDI       Context   initialContext = null;       try {         initialContext = new InitialContext();         dataSource = (DataSource)initialContext.lookup("java:comp/env/jdbc/StudentID");       } catch (Exception e) {         System.out.println("Cannot lookup dataSource " + e);         throw new javax.ejb.EJBException("Cannot lookup dataSource ");       }   }   return dataSource.getConnection(); }   But while executing the method i am getting following error Can you please tell me what is the reson.   Error java.lang.ClassCastException: student.JOnASStuBeanHome         at student.StudentBean.getConnection(StudentBean.java:59)         at student.StudentBean.getStudent(StudentBean.java:79)         at student.StudentBean.ejbCreate(StudentBean.java:39)         at student.JOnASStuBeanBean.ejbCreate(JOnASStuBeanBean.java:60)         at student.JOnASStuBeanHome.create(JOnASStuBeanHome.java:113)         at student.JOnASStuBeanHome_Skel.send(JOnASStuBeanHome_Skel.java:40)         at org.objectweb.david.libs.protocols.giop.GIOPProtocol$ServerSession_Lo w.send(GIOPProtocol.java:621)         at org.objectweb.jonathan.libs.protocols.tcpip.TcpIpProtocol$Session.run (TcpIpProtocol.java:396)         at org.objectweb.jonathan.libs.resources.JScheduler$JJob.run(JScheduler. java:265)  System exc. => Rollback the transaction.  JEntityHome.removeEJBObject: pk = null  postinvoke: System Exception in a home method:javax.ejb.EJBException: Cannot lo okup dataSource   Regards Surendra