java.lang.ClassCastException: $Proxy8 incompatible with lin.dao.impl.ExchangeDao

Spring transaction practice, an error example: 

 

package lin;
import lin.dao.impl.ExchangeDaoLocator;
import lin.dao.impl.TestDaoLocator;
import lin.domain.Exchange;
import lin.domain.Test;

import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;

public class DbTest {

	public static void main(String[] args) {

		try {
			ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("ApplicationContext.xml");
			
			JdbcTemplate jdbcTemplate = (JdbcTemplate) applicationContext.getBean("jdbcTemplate");
			jdbcTemplate.execute("select * from dual");
			
			ExchangeDaoLocator locator1 = (ExchangeDaoLocator) applicationContext.getBean("exchangeDaoLocator");
			Exchange exchange = locator1.findById("HK");
			System.out.println(exchange.getExchangeCode());
			
			TestDaoLocator locator2 = (TestDaoLocator) applicationContext.getBean("testDaoLocator");
			Test test = locator2.findById("1");
			System.out.println(test.getC2());
			
			System.out.println("----------------End----------------");
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

 

 

 

	<bean id="abstractDaoLocator" class="lin.dao.AbstractDaoLocator" abstract="true">
		<property name="sessionFactory" ref="sessionFactory"></property>
	</bean>
	
	<bean id="exchangeDaoLocator" class="lin.dao.impl.ExchangeDaoLocator" parent="abstractDaoLocator">
	</bean>

	<bean id="testDaoLocator" class="lin.dao.impl.TestDaoLocator" parent="abstractDaoLocator">
	</bean>

	<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
		<property name="sessionFactory" ref="sessionFactory"/>
		<property name="defaultTimeout" value="15"/>
		<property name="rollbackOnCommitFailure" value="true"/>
	</bean>
	
	<aop:config>
		<!-- Normal Example -->
		<aop:advisor pointcut="execution(* lin.DbTest..*(..))" advice-ref="requiresNewTxAdvice" />
		<!-- Wrong Example - java.lang.ClassCastException: $Proxy8 incompatible with lin.dao.impl.ExchangeDaoLocator -->
		<aop:advisor pointcut="execution(* lin.dao.impl.*.findById(..))" advice-ref="requiresNewTxAdvice" />
	</aop:config>
	
	<tx:advice id="requiresNewTxAdvice" transaction-manager="transactionManager">
		<tx:attributes>
			<tx:method name="*" propagation="REQUIRES_NEW" />
		</tx:attributes>
	</tx:advice>