hibernate出NullPointerException

public class PersonTest {    public static void main(String[] args) {
        Configuration cfg = new Configuration().configure();
        SessionFactory sf = cfg.buildSessionFactory();
        Session session = sf.openSession();
        try {
            Transaction transaction = session.beginTransaction();
            Person p = new Person();
            p.setId(5);
            p.setName("李震");
            p.setAge(22);
            session.save(p);
            transaction.commit();
        } finally {
            session.close();
        }
    }
}xml: 
  <hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="hibernate.connection.url">jdbc:oracle:thin:@127.0.0.1:1521:oracle</property>
        <property name="hibernate.connection.autocommit">false</property>
        <property name="hibernate.format_sql">true</property>
        <property name="hibernate.connection.username">scott</property>
        <property name="hibernate.connection.password">tiger</property>
        <!-- c3p0 -->
        <property name="hibernate.c3p0.max_size">20</property>
        <property name="hibernate.c3p0.min_size">5</property>
        <property name="hibernate.c3p0.timeout">5000</property>
        <property name="hibernate.c3p0.max_statements">3000</property>
        <property name="hibernate.c3p0.acquire_increment">2</property>
        <property name="hibernate.c3p0.validate">true</property>
        <property name="dialect">org.hibernate.dialect.OracleDialect</property>
        <property name="hbm2ddl.auto">update</property>
        <!-- mapping -->
        <mapping resource="c1/person.hbm.xml"/>
    </session-factory>
</hibernate-configuration>
异常信息: java.lang.NullPointerException
at oracle.jdbc.dbaccess.DBData.clearItem(DBData.java:431)
at oracle.jdbc.dbaccess.DBDataSetImpl.clearItem(DBDataSetImpl.java:3528)
at oracle.jdbc.driver.OraclePreparedStatement.clearParameters(OraclePreparedStatement.java:3401)
at com.mchange.v2.c3p0.stmt.GooGooStatementCache.refreshStatement(GooGooStatementCache.java:604)
at com.mchange.v2.c3p0.stmt.GooGooStatementCache.checkinStatement(GooGooStatementCache.java:236)
at com.mchange.v2.c3p0.impl.NewPooledConnection.checkinStatement(NewPooledConnection.java:239)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.close(NewProxyPreparedStatement.java:1807)
at org.hibernate.jdbc.AbstractBatcher.closePreparedStatement(AbstractBatcher.java:563)
at org.hibernate.jdbc.AbstractBatcher.closeStatement(AbstractBatcher.java:291)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:271)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:268)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)
at c1.PersonTest.main(PersonTest.java:21)