Beginner Spring with Hibernate integrated. Is this code correct?

[Khosrow Moossavi]

Hello Ranchers,

I've recently start to learn and integrate Spring and Hibernate to my Java web app (Struts2 as a presentation). I've googled a lot about tutorial and examples and so on. Well, everything seems ok and running based on the materials I've collected. but as long as I've deployed it on a hosting web server and got a Lot of Runtime java.lang.OutOfMemoryError exception, I wanted to clear things up to myself that everything I'm doing is correct as point of view of an expert, then assuming there are some issues about my Webserver Hosting or something else.
So here the Code:

web.xml

<web-app>
	....
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/applicationContext-hibernate.xml</param-value>
	</context-param>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
	
	<filter>
		<filter-name>struts2</filter-name>
		<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
        <init-param>
        	<param-name>config</param-name>
        	<param-value>struts-default.xml,struts-plugin.xml,struts.xml</param-value>
        </init-param>
	</filter>
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	....
</web-app>

struts.xml

<struts>
	<constant name="struts.enable.DynamicMethodInvocation" value="false" />
	<constant name="struts.objectFactory" value="spring" />
	<constant name="struts.devMode" value="true" />

	<package name="default" extends="struts-default" namespace="/">
		<action name="first" class="FirstAction">
			<result name="index">/web/content/first/index.jsp</result>
		</action>
	</package>
</struts>

applicationContext-hibernate.xml

<beans xmlns="http://www.springframework.org/schema/beans"
		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		xmlns:aop="http://www.springframework.org/schema/aop"
		xmlns:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="
			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
			http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
			http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

	

	<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="location"><value>/WEB-INF/jdbc.properties</value></property>
	</bean>

	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName"><value>${jdbc.driverClassName}</value></property>
		<property name="url"><value>${jdbc.url}</value></property>
		<property name="username"><value>${jdbc.username}</value></property>
		<property name="password"><value>${jdbc.password}</value></property>
	</bean>
	
	<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
		<property name="dataSource"><ref local="dataSource"/></property>
		
		<property name="configLocation">
			<value>classpath:my\classpath\domain\hibernate.cfg.xml</value>
		</property>

		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.dialect">${hibernate.dialect}</prop>
				<prop key="hibernate.show_sql">true</prop>
			</props>
		</property>
	</bean>


	<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
		<property name="sessionFactory"><ref local="sessionFactory"/></property>
	</bean>

	<import resource="/spring-context/spring-hibernate-daos.xml"/>
	<import resource="/spring-context/spring-hibernate-services.xml"/>
	<import resource="/spring-context/spring-hibernate-actions.xml"/>
</beans>

spring-hibernate-actions.xml

<beans>
	....
	<bean id="FirstAction" class="my.com.package.struts.action.FirstAction">
		<property name="firstService"><ref bean="firstService"/></property>
	</bean>  
	
	<bean id="SecondAction" class="my.com.package.struts.action.SecondAction">
		<property name="secondService"><ref bean="secondService"/></property>
	</bean>
	....
</beans>

spring-hibernate-services.xml

<beans>
	....
	<bean id="firstService" class="my.com.package.service.FirstServiceImpl">
		<property name="firstDAO"><ref bean="firstDAO"/></property>
	</bean>
	<bean id="secondService" class="my.com.package.service.SecondServiceImpl">
		<property name="secondDAO"><ref bean="secondDAO"/></property>
	</bean>
	....
</beans>

spring-hibernate-daos.xml

<beans>
	....
	<bean id="firstDAO" class="my.com.package.dao.FirstDAOImpl">
		<property name="sessionFactory"><ref bean="sessionFactory"/></property>
	</bean>
	<bean id="secondDAO" class="my.com.package.dao.SecondDAOImpl">
		<property name="sessionFactory"><ref bean="sessionFactory"/></property>
	</bean>
	....
</beans>

FirstAction.java

package my.com.package.struts.action;

import my.com.package.domain.First;
import my.com.package.service.FirstService;

public class FirstAction extends ActionSupport implements ServletRequestAware, ServletContextAware {
	private FirstService firstService;

	public String execute() {
		String successReturn = "index";

		First firstDomain = firstService.getContent();
		request.setAttribute("firstDomain", firstDomain);
		
		return successReturn;
    }


	public void setFirstService(FirstService firstService) {
		this.firstService= firstService;
	}
}

FirstServiceImpl.java

public class FirstServiceImpl implements FirstService {
	private FirstDAO firstDAO;
	
	public FirstServiceImpl() {}

	public First getContent(String lang) {
		First firstDomain = new First();
		
		List<First> firstContent = firstDAO.getContent();
		Iterator<First> firstContentItr = firstContent.iterator();
		
		if ( firstContentItr.hasNext() ) {
			firstDomain.setDescr(firstContent.get(0).getDescr());
			firstDomain.setInfoAvailable(true);
		}
		
		else {
			firstDomain.setInfoAvailable(false);
		}
		
		return firstDomain;
	}
	
	public void setFirstDAO(FirtsDAO firstDAO) {
		this.firstDAO= firstDAO;
	}
}

FirstDAOImpl.java

package my.com.package.dao;

import java.util.List;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import my.com.package.domain.First;

public class FirstDAOImpl extends HibernateDaoSupport implements FirstDAO {
	public AboutUsDAOImpl() {}
	
	public List<First> getContent(String lang) {
		List<First> firstContent = this.getHibernateTemplate().find("from First where isDeleted=0");
		
		return firstContent ;
	}
}

I'd really appreciate if anyone could help me whether I was on a right path or something seems wrong or Exception-Throwing-Material on the above application development.

Regards,
Khosrow.

[Mark Spritzler]

Actually it looks really clean to me.

There are a few suggestions, but for just starting out, they are really minor. Things you will learn as you learn more about Spring, like autowiring, And if you use recent Hibernate versions using the HibernateTemplate and HibernateDaoSupport is now antiquated. The reason why I say the last, is now you have a class that is coupled with a Spring class, the HibernateDaoSupport, so your Daos are no longer POJOs. Later, you might also like the Annotation route.

But again for a beginner that is great looking configuration and coding.

Mark