Thank you Edson so much for your reply. It is great help. I will
translate your reply and post back to
help the community. Would like to welcome you to the quality community
to share your valuable experience
with us !
You are right. The post was not very clear, my guess is it has high
demanding business changing needs
for his application.
Thanks,
Judy
Edson Richter wrote:
> Hi, Judy!
>
> It's possible to define a bit better what means "simplify"?
>
> Because if developer wants to use a server farm with clear separation
> between logic, persistence, view and workflow, then there is a price
> to pay for.
>
> If user just want to keep a simple application, then it would be
> better to just use plain MVC with JSP/Servlets/JPA; this would perform
> perfectly well for small number of users, but would not scale well if
> user need to work with redundant servers or in a server farm.
>
> Also, I've helped some developers to optimize his applications by
> hibrid solution, like using JSP/Servlets/JPA for crud, and
> JSP/Servlets/DB Server Side programming for business logic driven (not
> so good for high database usage).
>
> For a high demanding business changing needs and for distributed
> environment, then I would said the actual structure would connect very
> well with SOA/BPEL (of course, I had no time to deep analysis of the
> code, flaws or advantages - but looks logical).
>
> We could stay here and offer hundred approachs, but would be nice if
> developer would be a little bit clear in where he would like to go.
>
> Kind regards,
>
>
> Edson.
>
>
> > Date: Wed, 30 Jul 2008 18:50:34 -0700
> > From: Judy.J.Tang_at_Sun.COM
> > To: quality_at_glassfish.dev.java.net
> > Subject: EJB3 question, how to simplify it (translating a community
> post)
> >
> > Hi All,
> >
> > I am translating this post from the community. He said the EJB3 is
> > complicate for him to use, he wants to know if he can simplify
> > the following EJB3 structure.
> >
> > The information is from community, it may not be clear and complete.
> >
> > Thanks,
> > Judy
> >
> > --------------
> >
> > ORM: JPA
> > DAO: Stateless SessionBean
> > Business Logic Facade: Stateless Session Bean
> > Web Module: HTML/AJAX-->Spring MVC + jndi Business Logic Stateless
> > SessionBean
> >
> > Here is the JEB sample framwork:
> >
> > 1. Entity：
> > @Entity
> > public class Product {
> > @ID
> > Long id
> > .....
> > }
> >
> > 2. Generic DAO:
> > 2.1 Interface:
> > public interface GenericDao<T, PK extends Serializable> {
> > public T findByPk(PK pk);
> > public List<T> findAll();
> > public List<T> find(String query);
> > public void save(T object);
> > public T merge(T object);
> > public void remove(T object);
> > public void flush();
> > public void clear();
> > ......
> > }
> > 2.2 JPA Generic DAO implementation:
> > public class GenericDaoJpa<T, PK extends Serializable> implements
> > GenericDao<T, PK>{
> > @PersistenceContext
> > protected EntityManager entityManager;
> > protected Class<T> type;
> > // GenericDao
> > ......
> > }
> >
> > 3. Product DAO：
> > // DAO Local Interface
> > @Local
> > public interface ProductDaoLocal extends
> persistence.GenericDao<Product,
> > Long>{
> > }
> > //
> > @Stateless
> > public class ProductDao extends GenericDaoJpa<Product, Long> implements
> > ProductDaoLocal {
> > }
> >
> > 4. Business Logic Facade:
> > @Remote
> > public interface MyModuleFacade {
> > public void placeOrder(Long productId, Long customerId, int qty);
> > public List<TheOrder> findAllOrders();
> > }
> > @Local
> > public interface MyModuleFacadeLocal {
> > }
> > //
> > @Stateless
> > public class MyModuleFacadeBean implements facade.MyModuleFacade,
> > MyModuleFacadeLocal{
> > @javax.ejb.EJB
> > ProductDaoLocal productDao;
> >
> > @javax.ejb.EJB
> > CustomerDaoLocal customerDao;
> >
> > @javax.ejb.EJB
> > OrderDaoLocal orderDao;
> >
> > @javax.ejb.EJB
> > CustomerDiscountDaoLocal customerDiscountDao;
> >
> > public void placeOrder(Long productId, Long customerId, int qty) {
> > TheOrder theOrder = new TheOrder();
> > Customer customer = customerDao.findByPk(customerId);
> > Product product = productDao.findByPk(productId);
> > CustomerDiscount discount = customer.getDiscount();
> > theOrder.setDiscount(discount.getDiscount());
> > theOrder.setProduct(product);
> > theOrder.setPrice(product.getPrice() * qty * discount.getDiscount());
> > theOrder.setCustomer(customer);
> > theOrder.setQuantity(qty);
> > orderDao.save(theOrder);
> > }
> > }
> >
> > 5. Web Module references Facade:
> > 5.1 applicationContext.xml:
> > <jee:remote-slsb id="placeOrderFacade" jndi-name="facade.MyModuleFacade"
> > business-interface="facade.MyModuleFacade"/>
> > 5.2 home-servlet.xml中:
> > <bean id="placeOrderController" class="action.PlaceOrderController">
> > <property name="placeOrderFacade" ref="placeOrderFacade"/>
> > </bean>
> >
> >
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> > For additional commands, e-mail: quality-help_at_glassfish.dev.java.net
> >
>
>
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