在spring使用自带的dataSource配置：
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">是没问题的，使用druid连接池
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">就有问题。报如下错误：
java.lang.ClassCastException: com.alibaba.druid.pool.DruidPooledConnection cannot be cast to oracle.jdbc.OracleConnection
at oracle.sql.ArrayDescriptor.createDescriptor(ArrayDescriptor.java:105)
at oracle.sql.ArrayDescriptor.createDescriptor(ArrayDescriptor.java:73)异常代码：
Connection connection = ...;// Oracle
StructDescriptor st = new StructDescriptor("T_ORDER", connection);
// OR.
ARRAY deptArrayObject = new ARRAY(arrayDept, connection, list.toArray());
失败原因：
The connection pool usually has a wrapper around the real connection instance, that's why your cast fails.
连接池通常包装了一个真实的真实的Connection实例。
需要转换一下。
解决方案：
Connection connection = ...; // Oracle
// 增加此代码，将Connection转换为OracleConnection
connection = connection.unwrap(OracleConnection.class);
StructDescriptor st = new StructDescriptor("T_ORDER", connection);
参考链接：
