Update DB via EntityManager

Question

I'm working on a Spring-MVC project, trying to update a user's username and password using jpa. But I don't seem to be making any progress. :D

I checked other questions like this one and tried to use their approved answers for my case. Alas, nothing changes in my db.

By far, I have tried these methods and none has worked:

1. using persist before set, as suggested here

2. using merge after set as suggested here

3. commiting a transaction manually as suggested here.

Unfortunately, this class has a lot of foreign keys from all around my DB, and I can't safely remove the old one and add a new Dept with new data in it. So, here goes my update method -in DAO level of course- would someone please suggest a new way to update username and password here?

@Transactional
    public  Dept updateDept(int depId, String u, String p) {
        System.err.println("successfully reached DAO");
        Dept dep=entityManager.find(Dept.class,depId);

        dep.setUname(u);
        dep.setPassword(p);
        entityManager.merge(dep);

        return entityManager.find(Dept.class,depId); //just to check if update really happened, which did not
    }//end of update Dept

edit: Ok, so it is getting really complicated. I'm really a newbie in this area, so I try to give you as much detail as possible.

These are the only parts I was allowed to change, and I have to consider that any other configuration to other parts like JPA etc. is done by my senior team mate and is done correctly.

This is my controller which is supposed to update username and password of department manager, and send user back to their first page:

@RequestMapping(value="/infoEdit", method=RequestMethod.POST)
    public String editManager(HttpServletRequest req, @RequestParam("username") String  usernname , @RequestParam("password") String password , Model model) {
        int id= (Integer) req.getSession().getAttribute("id");

        boolean isUpdated=managerManagerImpl.updateUserPass(id,usernname,password);
        System.err.println(isUpdated);
        Dept d= managerManagerImpl.getDeptByManagerId(usernname,password);
        if (d!=null)

        return "themanager/managerFirstPage";

    }

In managerManagerImpl - implementation of managerManager interface , updateUserPass() goes like this:

@Override
    public Boolean updateUserPass(int id, String usernname, String password) {
        Dept dept=managerDAOImpl.getDept(id); // who is this?
        Dept possibleDup=managerDAOImpl.getDept(usernname);//maybe this username is taken
        Dept newDep=null;
        if(possibleDup==null || (possibleDup!=null && possibleDup.getId()==dept.getId())){//username is not taken
            System.err.println("going to update it!!");
            newDep=managerDAOImpl.updateDept(dept.getId(),usernname,password);
            System.err.println("newDep data here            : " + newDep.getId() + "// "+newDep.getUname());
            Dept newnewDept = managerDAOImpl.getDept(id);
            if(newnewDept!=null)
                System.err.println("&& newnewDep data here            : " + newnewDept.getId() + "// "+newnewDept.getUname());
        }
        Boolean isUpdated=(null!=newDep && newDep.getId()==dept.getId());
        return isUpdated;
    }

and this is my whole managerDAOImpl class:

@Repository
public class TheManagerDAOImpl {

    public TheManagerDAOImpl() {
    }

    @PersistenceContext
    public EntityManager entityManager;


    @Transactional
    public Prof getManager(String usern){
        String hql="SELECT p FROM Dept  p WHERE p.uname=:username";
        Query q= entityManager.createQuery(hql);
        q.setParameter("username",usern);
        List<Prof> res = (List<Prof>) q.getResultList();
        return res == null || res.size() == 0 ? null : res.get(0);
    }
    @Transactional
    public Dept getDept(int managerId) {
        String hql= "SELECT d FROM Dept  d WHERE  d.id=:idHere";
        Query q= entityManager.createQuery(hql);
        q.setParameter("idHere",managerId);
        List<Dept> res = (List<Dept>) q.getResultList();
        return res == null || res.size() == 0 ? null : res.get(0);
    }
    @Transactional
    public Dept getDept(String managerId, String managerPass) {
        String hql= "SELECT d FROM Dept  d WHERE d.uname=:username AND d.password=:pass";
        Query q= entityManager.createQuery(hql);
        q.setParameter("username",managerId);
        q.setParameter("pass",managerPass);
        List<Dept> res = (List<Dept>) q.getResultList();
        return res == null || res.size() == 0 ? null : res.get(0);
    }

    @Transactional
    public Dept getDept(String managerId) {
        String hql= "SELECT d FROM Dept  d WHERE d.uname=:username";
        Query q= entityManager.createQuery(hql);
        q.setParameter("username",managerId);
        List<Dept> res = (List<Dept>) q.getResultList();
        return res == null || res.size() == 0 ? null : res.get(0);
    }
    @Transactional
    public  Dept updateDept(int depId, String u, String p) {
        System.err.println("**************************here in dao");
        Dept dep=entityManager.find(Dept.class,depId);

        dep.setUname(u);
        dep.setPassword(p);
        entityManager.merge(dep);

        return entityManager.find(Dept.class,depId);
    }//end of update Dept


}

Just to mention, those System.error stuff are used to make sure it actually calls these methods, and are completely irrelevant.

Answer 1

You are getting container-manager persistence context, which has to get JTA datasource, but as I saw before(you have already removed it) from your persistence.xml, you are using resource local transactions (by specifying jdbc resource).

Correct configuration should be (for XML config)

1) Your datasource

<jdbc:embedded-database id="dataSource" type="H2">
    </jdbc:embedded-database>
// or jdbc:initialize-database for non-embedded

2) Your transaction manager

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
                <property name="entityManagerFactory" ref="emf"/>
            </bean>

2.1) As you are using annotation to do transaction demarcation you need

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

3) Your entity manager factory

bean id="emf" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
            </property>
            <property name="packagesToScan" value="com.myPackage"/>
            <property name="jpaProperties">
                <props>
                    <prop key="hibernate.dialect">org.hibernate.dialect.H2Dialect</prop>
                    <prop key="hibernate.max_fetch_depth">3</prop>
                    <prop key="hibernate.jdbc.fetch_size">50</prop>
                    <prop key="hibernate.jdbc.batch_size">10</prop>
                    <prop key="hibernate.show_sql">true</prop>
                </props>
            </property>
        </bean>

Answer 2

I found another way to do updates, which I'm not sure if it has any drawbacks, or it would blow my code up in the future. But since it solved this issue for now, I share it here. Maybe it will help.

For now I clear my entityManager before updating any existing entity. Somehow like this:

@Transactional
    public  void updateDept(Dept dep,String username, String password)  {
        entityManager.clear();
        dep.setUname(username);
        dep.setPassword(password);
        entityManager.merge(dep);
    }//end of update Dept

Surprisingly, it now works fine and commits updates on DB.