basic hibernate and spring mvc integration of view, dao, service and controller

Question

Status: Thankful to the answers but No one has answered the Important tag description in reflection to my simple code given. (20 Jul 13)

I have read many tutorials and yet every thing just mixes up or is only as a specific example that looks tiny or abstract.

I really cannot make something get logical in my mind. May be I learn with specific actual code.

Question: Can anyone show how to make the following incomplete code work completely with spring 3.x and hibernate 4.x.

Important:

I would like, even in this simple example, make sessionfactory and database quering by hibernate in the Service class (making boundry there as in large applications Service classes use many DAOs and commit transactions in one go)

I forget where i read it, perhaps in the spring documentation - but it clearly said, don't put @Transactional on your DAOs :P so generally, your service tier is where you define your transaction boundaries. a service method is typically a chunk of things that if all pass, commit otherwise fail and rollback That may not be a diehard rule of course, but its how we architected our enterprise resource planning web core. I forget where i read it, perhaps in the spring documentation - but it clearly said, don't put @Transactional on your DAOs

e.g http://blog.patouchas.net/technology/hibernate-dao-java-tutorial/ like without spring ?

The annotations are missing or incorrect. What should be the correct annotations.

Would there be any spring.xml (other than the usual) for these classes in specific? I would like to prefer only annotations if it works. correct annotations like @component , service, repository, resource, autowired

This is how I get the transaction generally

   Configuration configuration = new Configuration();
   configuration.configure();

   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
                                        .applySettings(configuration.getProperties())
                                        .buildServiceRegistry();

   SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
   Session session = sessionFactory.openSession();
   session.beginTransaction();
   session.getTransaction().commit();
   session.close();

now spring and hibernate

@Controller
public class UserController {
    private IUserService userService;

    @RequestMapping("/users")
    public String creatUser(){
        Users user = new Users();
        user.setEmail("myemail@mydomain.com");
        user.setName("myname");
        userService.creatUser(user);
        return "user-creation-result";      
    }
}

public class UserService implements IUserService{
    private IUserDAO userDAO;
    public void creatUser(Users user){
        //what to do here
        //how to call the sessionfactory
        //and call it in a way that each call
        // gives the same instance
         userDAO.creatUser(user);        
    }
}

public class UserDAO implements IUserDAO{
    public void creatUser(Users user){
        // what to do here?
    }
}

this wont be so important though.







    

        
        org.postgresql.Driver
        jdbc:postgresql://localhost:5432/postgres
        postgres
        abc

        
        1

        
        org.hibernate.dialect.PostgreSQLDialect

        
        org.hibernate.cache.internal.NoCacheProvider

        
        true

        
        create

        

        
        
        
        
        
        
        
        

    





@Entity
public class Users {
    @Id
    @GeneratedValue
    private long id;
    @ManyToMany
    private Collection groupList = new ArrayList();
    private String type; // admin / teamlead / normal
    private String name;
    private String email;
    private String password;
    @Lob
    private String description;
    private boolean isEnabled;

    /**
     * @return the id
     */
    public long getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(long id) {
        this.id = id;
    }

    /**
     * @return the groupdId
     */


    /**
     * @param groupdId the groupdId to set
     */


    /**
     * @return the type
     */
    public String getType() {
        return type;
    }

    /**
     * @param type the type to set
     */
    public void setType(String type) {
        this.type = type;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the email
     */
    public String getEmail() {
        return email;
    }

    /**
     * @param email the email to set
     */
    public void setEmail(String email) {
        this.email = email;
    }

    /**
     * @return the password
     */
    public String getPassword() {
        return password;
    }

    /**
     * @param password the password to set
     */
    public void setPassword(String password) {
        this.password = password;
    }

    /**
     * @return the isEnabled
     */
    public boolean isIsEnabled() {
        return isEnabled;
    }

    /**
     * @param isEnabled the isEnabled to set
     */
    public void setIsEnabled(boolean isEnabled) {
        this.isEnabled = isEnabled;
    }

    /**
     * @return the groupList
     */
    public Collection getGroupList() {
        return groupList;
    }

    /**
     * @param groupList the groupList to set
     */
    public void setGroupList(Collection groupList) {
        this.groupList = groupList;
    }

    /**
     * @return the description
     */
    public String getDescription() {
        return description;
    }

    /**
     * @param description the description to set
     */
    public void setDescription(String description) {
        this.description = description;
    }
}

Paul Vargas · Accepted Answer

If you are using Spring 3.x and Hibernate 4.x, you can consider a three-tier application architecture:

Data tier

You could have an abstract base class for common DAO methods.

public abstract class AbstractDAO {

    private final transient Class entityClass;

    public AbstractDAO(final Class entityClass) {
        this.entityClass = entityClass;
    }

    protected abstract EntityManager getEntityManager();

    public final E find(final PK id) {
        return getEntityManager().find(entityClass, id);
    }

    // Another common methods

}

In every DAO implementation, you can put particular methods for that DAO.

@Repository
public final class UserDAO extends AbstractDAO {

    @Autowired
    private transient EntityManagerFactory emf;

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

    @Override
    protected EntityManager getEntityManager() {
        return emf.createEntityManager();
    }

    // particular methods for this DAO

}

Application tier

What if the user does not exist? Put this logic in this tier.

@Service
public final class UserService {

    private static final Logger LOG = LoggerFactory.getLogger(UserService.class);

    @Autowired
    private transient UserDAO userDAO;

    public User findUser(final Long id) {
        return userDAO.find(id);
    }

}

Presentation tier

@Controller
@RequestMapping("/user")
public final class UserController {

    private static final Logger LOG = LoggerFactory
                            .getLogger(UserController.class);

    @Autowired
    private transient UserService userService;

    @RequestMapping(value = "/find/{id}", method = RequestMethod.GET)
    public void downloadImage(
            @PathVariable("id") final Long id, 
            final HttpServletResponse response) throws IOException {
        // 
    }

}

The web.xml, this contains the Application config and the Dispatcher config:



  MyWebApp

  
  
    log4jConfigLocation
    classpath:log4j.xml
  
  
    webAppRootKey
    MyWebApp.root
  
  
    org.springframework.web.util.Log4jConfigListener
  

  
  
    org.springframework.web.context.ContextLoaderListener
  
  
    dispatcher
    org.springframework.web.servlet.DispatcherServlet
    1
  
  
    dispatcher
    /
  

  
  
    index.jsp

The dispatcher-servlet.xml:

And if you want to avoid the persistence.xml file, you can have it in your applicationContext.xml:

I hope this can help you.

basic hibernate and spring mvc integration of view, dao, service and controller

Answers (2)

Data tier

Application tier

Presentation tier

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