Clas cast exception in using Clobs

Question

Hi,
          Recently I upgraded from wblogic6.1 SP5 to SP6 and from jdk1.3.1_07 to jdk1.3.1_09.
          After the upgrade, I'm getting a class cast exception when I try to cast a java.sql.Clob to oracle.sql.CLOB. Here is the line of code which throws up the ClassCastException:
          oracle.sql.CLOB message = (oracle.sql.CLOB)cs.getClob(3);
          Where cs is a java.sql.CallableStatement
          I'd appreciate any help or suggestion in this regard
          Dipak Jha

Answer 1

It's hard to tell from the few information you give, but I'd
guess toward a serialization problem.
If some kind of server hold java objects it might decid to serialize the objects and store them on the harddisc for later use. If it tries to deserialize such an object after the class file has changed you might get a class cast exception.
You get this behaviour with Tomcat when you update the class file while tomcat is running.
If your problem is along this line it would explain why it isn't a problem on other machines (no old serializede objects there). And it should go away if you shut down the server remove all kinds of persistant cache it might have and start it up again.
To permanently fix the problem have a look in the java tutorial under serialization. There is some kind of id that you can set to deserialize old objects.
HTH
Spieler