Oracle JDBC exception in Servlet-RMI-Db communication

[Parvinder Singh Arora]

Hi All,

I am getting a improper exception on a query execution

My servlet's doPost(..) looks up for a RMI Server which has FSDBAccess
class which actully takes care of all the DB transactions

If i execute a query through my servlet (which looks up for RMI Server
and RMI Server delegates the query execution to FSDBaccess ) and the
query has some error then the exception which it throws is not
java.sql.SQLException ...It is something like this

java.lang.NullPointerException
at oracle.net.ns.NetException.<init>(Unknown Source)
at oracle.net.ns.BreakNetException.<init>(Unknown Source)
at oracle.net.ns.NetInputStream.processPacket(Unknown Source)
at oracle.net.ns.NetInputStream.getNextPacket(Unknown Source)
at oracle.net.ns.NetInputStream.read(Unknown Source)
at oracle.net.ns.NetInputStream.read(Unknown Source)
at oracle.net.ns.NetInputStream.read(Unknown Source)
at oracle.jdbc.ttc7.MAREngine.unmarshalUB1(MAREngine.java:718)
at oracle.jdbc.ttc7.MAREngine.unmarshalSB1(MAREngine.java:690)
at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:372)
at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1311)
at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteFetch(TTC7Protocol.java:738)
at oracle.jdbc.driver.OracleStatement.executeNonQuery(OracleStatement.java:1313)
at oracle.jdbc.driver.OracleStatement.doExecuteOther(OracleStatement.java:1232)
at oracle.jdbc.driver.OracleStatement.doExecuteWithBatch(OracleStatement.java:1353)
at oracle.jdbc.driver.OracleStatement.doExecute(OracleStatement.java:1760)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1805)
.
.
.
.

and if i execute the same query directly through RMIServer->FSDbaccess
and not through "Servlet->RMI Server->FSDbaccess" it properly throws
the exception as follows

java.sql.SQLException: ORA-02291: integrity constraint
(PATHTEMP.SYS_C001527) violated - parent key not found

at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:114)
at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:208).........
.
.
.

Now i fail to understand that why in case of Servlet->RMI
Server->FSDbaccess sequence it throws a different exception ?

In case of "Servlet->RMIServer->FSDbaccess" sequence once the
exception is thrown by some query ..and if it goes ahead and try
executing some other query it does not executes any query , even if it
tries to get a new connection it again throws the same exception (net
exception)

Am i missing some RMI permissions or something ? or is there a problem
with oracle driver ??.. I am using the Oracle thin driver
(classes12.zip)

Any ideas ??

Regards

~Parvinder