HibernateDaoSupport - BeanNameAutoProxyCreator - ClassCast Exception

[aravindbv]

I am trying a simple logging interceptor for a bean which extends HibernateDaoSupport..When i try to do getBean and cast it to my bean, i get java.lang.ClassCastException: $Proxy4..

if i remove extends from HibernateDaoSupport, aspect with BeanNameAutoProxyCreator works fine and if remove BeanNameAutoProxyCreator aspect, just the dao and hibernate works fine..it only fails if i extend hibernatedaosupport and apply beannameautoproxy aspect..

1)below is my java file

package springex;
import net.sf.hibernate.SessionFactory;
/**
 * @author administrator
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */


public class AdderImpl extends org.springframework.orm.hibernate3.support.HibernateDaoSupport
{
	//private SessionFactory sessionFactory;
    public int add(int arg0, int arg1)
    {
        return arg0 + arg1;
    }

    public void add(){
	}

}

2)below is my spring config

<beans>	
 
 	 <bean id="appDataSource" class="org.apache.commons.dbcp.BasicDataSource">
  		<property name="driverClassName"><value>COM.ibm.db2.jdbc.app.DB2Driver</value></property>
  	        <property name="url"><value>jdbc:db2:dbname</value></property>
  		<property name="username"><value>userid</value></property>
  		<property name="password"><value>password</value></property>
  	</bean> 
  
  	<bean id="appHibernateProperties" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
  		<property name="properties">
  			<props>
  				<prop key="hibernate.hbm2ddl.auto">update</prop>
  				<prop key="hibernate.dialect">org.hibernate.dialect.DB2Dialect</prop>
  				<prop key="hibernate.query.substitutions">true 'T', false 'F'</prop>
  				<prop key="hibernate.show_sql">true</prop>
  				<prop key="hibernate.c3p0.minPoolSize">5</prop>
  				<prop key="hibernate.c3p0.maxPoolSize">20</prop>
  				<prop key="hibernate.c3p0.timeout">600</prop>
  				<prop key="hibernate.c3p0.max_statement">50</prop>
  				<prop key="hibernate.c3p0.testConnectionOnCheckout">false</prop>
  			</props>
  		</property>
	</bean>
	
	<bean id="appSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
		<property name="dataSource"><ref local="appDataSource"/></property>
		<property name="hibernateProperties">
			<ref bean="appHibernateProperties" />
		</property>
			
			
		<property name="mappingResources">
			<list>
			         <value>Mapping.hbm.xml</value>
		   	</list>
		</property>
			
			
	</bean>
  	 <bean id="Adder1" class="springex.AdderImpl">
	  	<property name="sessionFactory"><ref local="appSessionFactory"/></property>
	  </bean>	
  <bean id="loggingInterceptor" class="springex.LoggingInterceptor"/>
  <bean id="loggingProxy"
       class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
       <property name="beanNames">
         <list>
           <value>*</value>
         </list>
       </property>
       <property name="interceptorNames">
         <list>
           <value>loggingInterceptor</value>
         </list>
       </property>
    </bean>

3)below is my class that invokes..

public static void main(String[] args)
    {
    	ClassPathXmlApplicationContext appContext = new ClassPathXmlApplicationContext(new String[] {
        "springbeans.xml"   });

System.out.println ("class :: " + appContext.getBean("Adder1"));
        AdderImpl a = (AdderImpl) appContext.getBean("Adder1");
        System.out.println("result = " + a.add(4, 7));
}

4)below is my classpath

db2java.zip;
commons-dbcp.jar;
commons-pool.jar;
db-ojb-1.0.4.jar;
hibernate2.jar;
spring.jar; (1.2.8)
spring-aop.jar;
commons-logging-api.jar;
jta.jar;
dom4j-1.5.2.jar;
commons-collections-3.0.jar;
ehcache-1.1.jar;
hibernate3.jar;
cglib-nodep-2.1_3.jar

[Colin Yates]

Best practice kinda dictates that you build to interfaces, so you should really have an Addr interface which you can then cast to.

[aravindbv]

it works fine if i have an interface...i have existing project which has developed classes...so i wanted to use BeanNameAutoProxyCreator so that i dont need to define interfaces for all these classes..

[sabarish]

Can you try setting the proxyTargetClass property of the BeanNameAutoProxyCreator to the value 'true' (without the quotes)?

[aravindbv]

thanks that works..if i give * for beanNames values then i get exception as below...If i give Add*, it works fine without interface...

<bean id="loggingProxy"
       class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
       <property name="beanNames">
         <list>
           <value>*</value>
         </list>
       </property>
       <property name="interceptorNames">
         <list>
           <value>loggingInterceptor</value>
         </list>
       </property>
    </bean>

Exception

Exception in thread "main" org.springframework.beans.factory.FactoryBeanNotIniti
alizedException: Error creating bean with name 'appHibernateProperties': Factory
Bean returned null object: probably not fully initialized (maybe due to circular
 bean reference)

[sabarish]

Yes a * would affect all beans defined in the app context.

[aravindbv]

thanks for the reply...will there be performance hit if i use BeanNameAutoProxyCreator with <property name="proxyTargetClass" value="true" />..or do i need to define interfaces for all classes that dont have it and not use proxyargeClass to true for better performance..

[sabarish]

thanks for the reply...will there be performance hit if i use BeanNameAutoProxyCreator with <property name="proxyTargetClass" value="true" />..or do i need to define interfaces for all classes that dont have it and not use proxyargeClass to true for better performance..

There is a slight performance difference between JDK dynamic proxying and CGLIB proxying. And this difference fluctuates with each JDK release. So the exact loss/gain would depend on your JDK version. I have not noticed any "visible" performance losses myself but you may want to test it out for your application.

[Colin Yates]

I did some stupidly trivial performance tests on my old blog (http://blogs.warwick.ac.uk/colinyates/) which essentially created 10000 instances of a class and then performed 10000 calls on a method.

It timed this for a class, a class extended by CGLIB and a class wrapped in a JDK proxy. The stats were that the 10000x10000 native calls took something like 37ms, the CGLIB took 200ms and the JDK (1.5_05) proxy took 700ms. I did the same thing on the latest JDK (1.5_07) and the proxy calls took about the same time as the CGLIB.

I cannot link to the original article because the blog system is currently down

[dejanp]

import net.sf.hibernate.SessionFactory;
...
org.springframework.orm.hibernate3.support.Hiberna teDaoSupport

You are trying to use Hib2 SessionFactory and Hib3 Dao Support.