数据库连接的问题!

oracle数据连接池, 用这种方式更新表,有时出现错误,请问是什么原因,如何解决?
 pstment = con.prepareStatement(strSql,
                                       ResultSet.TYPE_SCROLL_SENSITIVE,
                                       ResultSet.CONCUR_UPDATABLE);
 rst = pstment.executeQuery();
错误如下
java.sql.SQLException: Io exception: Connection reset
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:333)
at oracle.jdbc.driver.OracleStatement.<init>(OracleStatement.java:389)
at oracle.jdbc.driver.OracleStatement.<init>(OracleStatement.java:413)
at oracle.jdbc.driver.OraclePreparedStatement.<init>(OraclePreparedStatement.java:119)
at oracle.jdbc.driver.OracleConnection.privatePrepareStatement(OracleConnection.java:944)
at oracle.jdbc.driver.OracleConnection.prepareStatement(OracleConnection.java:857)
at sms.app.service.post.HttpPostService.postMessage(HttpPostService.java:110)
at sms.app.service.post.HttpPostService$1.run(HttpPostService.java:21)
at java.util.TimerThread.mainLoop(Timer.java:432)
at java.util.TimerThread.run(Timer.java:382)