I have this problem:
i prepare the view with the entity
@RequestMapping("/admin/modifyImplant/{id}")
public ModelAndView modifyImplant(@PathVariable Integer id) {
ModelAndView mav = new ModelAndView();
Implant currentImplant =impDAO.findById(id); //this is the dao
Implanttype it= currentImplant.getImplanttype();
Implantinverter ii=new Implantinverter();
ArrayList<Implantpanel> implantpanels = new ArrayList<Implantpanel>();
try{
ii= (Implantinverter)currentImplant.getImplantinverters().toArray()[0];
implantpanels=(ArrayList<Implantpanel>) imppanelDAO.findByProperty("implant",currentImplant );
}
catch (Exception ex){
//TODO
}
mav.addObject("implantpanels", implantpanels);
mav.addObject("implantinverter",ii);
mav.addObject("implant", currentImplant); //THIS IS THE ENTITY I MEAN
mav.addObject("implanttype",it);
mav.setViewName("/implant/modifyImplant.jsp");
return mav;
}
This code approach to a jsp ( a little portion of code)
<form:form action="${pageContext.request.contextPath}/admin/finalizeModifyImplant/${implant.id}" method="POST" modelAttribute="implant">
<table cellpadding="0" cellspacing="0" id="viewTable" >
<tbody>
<tr>
<td class="label">
Name:
</td>
<td>
<form:input id="User_namesurname" path="businessname" cssStyle="width:300px;"/>
</td>
</tr>
and so on for the fields of entity. The entity has some entity related, connected by foreign key ( like implanttype, implantinverter, implantpanels ).
the submission go to this controller:
@RequestMapping(value = "/admin/finalizeModifyImplant/{id}",
method = { RequestMethod.GET,RequestMethod.POST })
public ModelAndView finalizeModifyImplant(@PathVariable int id, @Valid @ModelAttribute Implant implant, BindingResult result){
ModelAndView mav=new ModelAndView();
mav.setViewName("../../admin/modifyImplant/"+id);
if (result.hasErrors()){
return mav;
}
implant.setId(id); //NOTICE WHAT I NEED TO DO HERE!
Implant oldImplant= impDAO.findById(id);
implant.setImplantinverters(oldImplant.getImplantinverters());
implant.setImplantpanels(oldImplant.getImplantpanels());
implant.setImplanttype(oldImplant.getImplanttype());
implant.setInverters(oldImplant.getInverters());
implant.setPvgis(oldImplant.getPvgis());
try{
impDAO.merge(implant); //here i call getSession().merge()
}catch(RuntimeException re){
return mav;
//TODO: errors
}
when i get the form submission (this is an update) i have the following problems: 1. the returning implant has no id (field id=null) 2. the related entities are also null.
following is the implant entity
public class Implant implements java.io.Serializable {
// Fields
private Integer id;
private Pvgis pvgis;
private Gateway gateway;
private Implanttype implanttype;
@JsonIgnore //I NEED TO JSONIGNORE IT BECAUSE IT HAS A RECURSIVE CALL ON IMPLANT
private Users users;
@NotEmpty
private String nameimplant;
private String place;
private double latitude;
private double longitude;
private double expectedpower;
private double tolerance;
[...] and many other fields
and the related implant.hbm.xml
<hibernate-mapping>
<class name="it.pstmarche.model.Implant" table="implant" schema="public">
<id name="id" type="integer">
<column name="id" />
<generator class="identity" />
</id>
<many-to-one name="pvgis" class="it.pstmarche.model.Pvgis" fetch="select">
<column name="idpvgis" />
</many-to-one>
<many-to-one name="gateway" class="it.pstmarche.model.Gateway" fetch="select">
<column name="idgateway" />
</many-to-one>
<many-to-one name="implanttype" class="it.pstmarche.model.Implanttype" fetch="select">
<column name="implanttype" />
</many-to-one>
<many-to-one name="users" class="it.pstmarche.model.Users" fetch="select" >
<column name="iduser" />
</many-to-one>
<property name="nameimplant" type="string">
<column name="nameimplant" not-null="true">
<comment>Name</comment>
</column>
i really cannot figure how to do correctly the update, because when i try to get the updated entity from the db (via findById or directly a query) i get random result, sometimes i get the correct and updated entity, sometimes i get the old entity!! Really random.
I tried: 1. removing the cache ( session.setCacheMode(CacheMode.IGNORE); ) with no result 2. adding getSession().flush(); getSession().close(); at the end of the merge method, that:
public void merge(Implant currentImp){
//Session session = HibernateSessionFactory.getSessionFactory().openSession();
Transaction tx= getSession().beginTransaction();
if (currentImp.getId() != null) { // it is an update
getSession().merge(currentImp);
tx.commit();
//getSession().update(currentImp);
log.debug("MERGE");
getSession().flush();// THAT'S THE ADD
session.close(); //THIS IS ALSO
} else { // you are saving a new one
getSession().saveOrUpdate(currentImp);
tx.commit();
getSession().flush();
getSession().close();
log.debug("Save sou");
}
I really cannot figure what is the correct way to implement updates with Hibernate + Spring! Any help is appreciated. Thanks
EDIT: Maybe my question was not clear. The current problem is, after i save or merge an entity, randomly, when i search the entity (like by a query findById(int id)) i get randomly the old entity (that i think it's still in the Hibernate session). The only way to override this problem is clearing the session (getSession().clear()), but after this i obviously get Lazy exceptions - no proxy when i try to get the related entities of the entity i need that is in the cleared session! that's a shame
2EDIT: Thanks Tim H. However, i still facing issues related to handling hibernate sessions. preface: i use hibernate session per-thread, like
private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
private static Configuration configuration = new Configuration();
private static org.hibernate.SessionFactory sessionFactory;
private static String configFile = CONFIG_FILE_LOCATION;
static {
try {
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
} catch (Exception e) {
System.err
.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
private HibernateSessionFactory() {
}
public static Session getSession() throws HibernateException {
Session session = (Session) threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession()
: null;
threadLocal.set(session);
}
return session;
}
Now, suppose i load entity x from the db, on Tomcat thread 1. The entity value is 100. I cannot close the session after loading it because it's lazy initialized(and if i close the session, i risk to get a lazy initialization exception - No Proxy/session).
After, i update the value of entity x on thread 2. The value now is 50.
Finally, i load back the value, but tomcat got me to thread 1, where the entity is still in the session of the thread, and the value is still 100. I get the old value instead the new one!!
So, i cannot close the session until my jsp is finished (i use the lazy fields on that), i have to do this anti-pattern to close the session at the end of jsp via: <% HibernateSessionFactory.getSession().close(); %> and that is horrible! i couple the view with the model! there is a pattern to do this safely??
