Oracle JDBC connection with Weblogic 10 datasource mapping, giving problem java.sql.SQLException: Closed Connection

I am using weblogic 10 JNDI datasource to create JDBC connections, below is my config

http://www.bea.com/ns/weblogic/920.xsd"> XL-Reference-DS jdbc:oracle:oci:@abc.XL.COM oracle.jdbc.driver.OracleDriver user DEV_260908 password password dll ocijdbc10 protocol oci oracle.jdbc.V8Compatible true baseDriverClass oracle.jdbc.driver.OracleDriver 1 100 1 true SQL SELECT 1 FROM DUAL ReferenceData OnePhaseCommit

When I run a bulk task where there are lotsa connection made and closed, sometimes it gives connection closed exception for any of the task in the bulk task.

Below is detailed exception'

java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:111) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:207) at oracle.jdbc.driver.OracleStatement.ensureOpen(OracleStatement.java:3512) at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3265) at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:3367)

Any pointers ?

Thanks in advance, Gaurav