Implementation of Annotation Driven Transaction in Open-Session-In-View with Spring 3 and Hibernate 4

Question

I am developing an application with Wicket-1.5.3, Spring-3.1.1 and Hibernate-4.1.1.

I want to implement

• Open-Session-In-View Pattern where the
• Transaction will be Annotation Driven and the
• Application should net get any LazyInitializationException, also the
• Database update operations for nested Models need to be done correctly.

I have separate layers, web, data, service etc.

At first I want to state the open-session-in-view filter defined in web.xml:

<filter>
    <filter-name>openSessionInView</filter-name>
    <filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>openSessionInView</filter-name>
    <url-pattern>/app/*</url-pattern>
</filter-mapping>

In applicationContext.xml I have the following configurations:

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost:3306/ems" />
    <property name="username" value="root" />
    <property name="password" value="admin" />
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">create</prop>
        </props>
    </property>
    <property name="mappingDirectoryLocations" value="/WEB-INF/resources/mappings" />
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<tx:annotation-driven transaction-manager="transactionManager" />   

<bean id="transactionInterceptor" class="org.springframework.transaction.interceptor.TransactionInterceptor">
    <property name="transactionManager" ref="transactionManager" />
    <property name="transactionAttributeSource">
        <bean class="org.springframework.transaction.annotation.AnnotationTransactionAttributeSource" />
    </property>
</bean>

<bean id="managerTemplate" abstract="true" class="org.springframework.aop.framework.ProxyFactoryBean">
    <property name="interceptorNames">
        <list>
            <value>transactionInterceptor</value>
        </list>
    </property>
</bean>

<bean id="userDao" class="app.dev.ems.data.dao.impl.UserDaoImpl">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<bean id="userManager" parent="managerTemplate">
    <property name="target">
        <bean class="app.dev.ems.manager.impl.UserManagerImpl">
            <property name="userDao" ref="userDao" />
        </bean>
    </property>
</bean> 

The data model classes defined in *.hbm.xml are proxy based:

<class name="app.dev.ems.data.model.impl.User" table="USER" proxy="app.dev.ems.data.model.IUser">
    <id name="id" column="ID">
        <generator class="native"/>         
    </id>
    <property name="name" column="NAME" not-null="true" />
</class>

Now I am describing the classes defined in applicationConext:

The userDao: it is actually UserDaoImpl:

public class UserDaoImpl extends BaseDaoImpl<User> implements IUserDao {

    public UserDaoImpl() {
        super(User.class);
    }   
}

The BaseDaoImpl is an abstract class in which the dependency injection of sessionFactory is actually happens:

public abstract class BaseDaoImpl<T extends Base> implements IBaseDao<T> {

    private Class<T> entityClass;
    private SessionFactory sessionFactory;

    public BaseDaoImpl(Class<T> entityClass) {
        super();
        this.entityClass = entityClass;
    }   

    public SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    @SuppressWarnings("unchecked")
    public List<T> getAll() {
        return getSessionFactory().getCurrentSession().createCriteria(entityClass).list();
    }

    public Integer save(T entity) {
        return (Integer) getSessionFactory().getCurrentSession().save(entity);
    }
}

Here I have a question regarding this class. I was wondering whether or not it would be better if I extends BaseDaoImpl with HibernateDaoSupport? If I do so then the alternate version of the save method will be:

public Integer save(final T entity) {
    return getHibernateTemplate().execute(new HibernateCallback<Integer>() {

        @Override
        public Integer doInHibernate(Session session) throws HibernateException, SQLException {
            return (Integer) session.save(entity);
        }
    });
}

Which one is better?

Next the interface IBaseDao:

public interface IBaseDao<T extends Base> extends ISupportSave<T, Integer> {

    List<T> getAll();
}

And the ISupportSave:

public interface ISupportSave<T extends Base, U extends Number> {

    U save(T entity);
}

The UserDaoImpl implements IUserDao and which is:

public interface IUserDao extends IBaseDao<User> {

}

Next comes the service layer and among the other class I am describing userManager and they are Transactional:

@Transactional
public class UserManagerImpl extends BaseManagerImpl<User> implements IUserManager {

    @SuppressWarnings("unused")
    private IUserDao userDao;

    public void setUserDao(IUserDao userDao) {
        super.setEntityDao(userDao);
        this.userDao = userDao;
    }   
}

The BaseManagerImpl is an abstract class which is extended by UserManagerImpl:

@Transactional
public abstract class BaseManagerImpl<T extends Base> implements IBaseManager<T> {

    private IBaseDao<T> entityDao;

    public void setEntityDao(IBaseDao<T> entityDao) {
        this.entityDao = entityDao;
    }

    @Transactional(readOnly = false, propagation = Propagation.REQUIRED)
    public Integer save(T entity) {
        return entityDao.save(entity);
    }
}

Following is the IBaseManager:

public interface IBaseManager<T extends Base> {

    Integer save(T entity);
}

And the IUserManager is:

public interface IUserManager extends IBaseManager<User> {

}

I didn't gave the model classes. Mainly I have User which implements IUser and extends Base. IUser in turns extends IBase and also Base implements IBase.

Now I was wondering whether the above designing is correct and will it fulfill my requirement or not.

Any suggestion will be very helpful to me.

Thanks.

Answer 1

1. HibernateTemplate is not recommanded any more in Spring 3.1. See here

2. I'm not in a good position to evaluate your design of service/dao layer since there is only a rough context of your project. But I suggest you have a look at appfuse project , I'm sure you'll get good hints from its source code.