I am using spring mvc with hibernate and JPA. I have a Person class which is inherited by another class called Agent. The mapping is implemented as follows:
#Entity
#Table(name = "Person")
#Inheritance(strategy = InheritanceType.JOINED)
public class Person extends Auditable implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "PersonId")
protected Long id;
//other variables
...
}
#Entity
#PrimaryKeyJoinColumn(name = "PersonId")
public class Agent extends Person implements Serializable {
//additional agent specific variables go here
...
}
Saving new data is smooth and I have no problem there. however, when I edit data, everything except the id value is bound to the controller method's model attribute. I have verified that the id has been sent along with other items from the browser using chrome's developer tools. but the id field at the controller is always null and as a result the data is not updated. This is what my controller method looks like:
#RequestMapping(value = "register", method = RequestMethod.POST)
public #ResponseBody CustomAjaxResponse saveAgent(ModelMap model, #ModelAttribute("agent") #Valid Agent agent, BindingResult result) {
...
}
I suspect the problem is probably with my inheritance mapping because I have other classes inheriting from the Person class and I face a similar problem there as well.
Please help!
you need a public setter for id.
In cases like this I commonly use a specific dto for the form, and/or implement a conversion service that retrieves the entity via hibernate based on id and then performs a merge.
Related
I have a database service using Spring Boot 1.5.1 and Spring Data Rest. I am storing my entities in a MySQL database, and accessing them over REST using Spring's PagingAndSortingRepository. I found this which states that sorting by nested parameters is supported, but I cannot find a way to sort by nested fields.
I have these classes:
#Entity(name = "Person")
#Table(name = "PERSON")
public class Person {
#ManyToOne
protected Address address;
#ManyToOne(targetEntity = Name.class, cascade = {
CascadeType.ALL
})
#JoinColumn(name = "NAME_PERSON_ID")
protected Name name;
#Id
protected Long id;
// Setter, getters, etc.
}
#Entity(name = "Name")
#Table(name = "NAME")
public class Name{
protected String firstName;
protected String lastName;
#Id
protected Long id;
// Setter, getters, etc.
}
For example, when using the method:
Page<Person> findByAddress_Id(#Param("id") String id, Pageable pageable);
And calling the URI http://localhost:8080/people/search/findByAddress_Id?id=1&sort=name_lastName,desc, the sort parameter is completely ignored by Spring.
The parameters sort=name.lastName and sort=nameLastName did not work either.
Am I forming the Rest request wrong, or missing some configuration?
Thank you!
The workaround I found is to create an extra read-only property for sorting purposes only. Building on the example above:
#Entity(name = "Person")
#Table(name = "PERSON")
public class Person {
// read only, for sorting purposes only
// #JsonIgnore // we can hide it from the clients, if needed
#RestResource(exported=false) // read only so we can map 2 fields to the same database column
#ManyToOne
#JoinColumn(name = "address_id", insertable = false, updatable = false)
private Address address;
// We still want the linkable association created to work as before so we manually override the relation and path
#RestResource(exported=true, rel="address", path="address")
#ManyToOne
private Address addressLink;
...
}
The drawback for the proposed workaround is that we now have to explicitly duplicate all the properties for which we want to support nested sorting.
LATER EDIT: another drawback is that we cannot hide the embedded property from the clients. In my original answer, I was suggesting we can add #JsonIgnore, but apparently that breaks the sort.
I debugged through that and it looks like the issue that Alan mentioned.
I found workaround that could help:
Create own controller, inject your repo and optionally projection factory (if you need projections). Implement get method to delegate call to your repository
#RestController
#RequestMapping("/people")
public class PeopleController {
#Autowired
PersonRepository repository;
//#Autowired
//PagedResourcesAssembler<MyDTO> resourceAssembler;
#GetMapping("/by-address/{addressId}")
public Page<Person> getByAddress(#PathVariable("addressId") Long addressId, Pageable page) {
// spring doesn't spoil your sort here ...
Page<Person> page = repository.findByAddress_Id(addressId, page)
// optionally, apply projection
// to return DTO/specifically loaded Entity objects ...
// return type would be then PagedResources<Resource<MyDTO>>
// return resourceAssembler.toResource(page.map(...))
return page;
}
}
This works for me with 2.6.8.RELEASE; the issue seems to be in all versions.
From Spring Data REST documentation:
Sorting by linkable associations (that is, links to top-level resources) is not supported.
https://docs.spring.io/spring-data/rest/docs/current/reference/html/#paging-and-sorting.sorting
An alternative that I found was use #ResResource(exported=false).
This is not valid (expecially for legacy Spring Data REST projects) because avoid that the resource/entity will be loaded HTTP links:
JacksonBinder
BeanDeserializerBuilder updateBuilder throws
com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of ' com...' no String-argument constructor/factory method to deserialize from String value
I tried activate sort by linkable associations with help of annotations but without success because we need always need override the mappPropertyPath method of JacksonMappingAwareSortTranslator.SortTranslator detect the annotation:
if (associations.isLinkableAssociation(persistentProperty)) {
if(!persistentProperty.isAnnotationPresent(SortByLinkableAssociation.class)) {
return Collections.emptyList();
}
}
Annotation
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.FIELD)
public #interface SortByLinkableAssociation {
}
At project mark association as #SortByLinkableAssociation:
#ManyToOne
#SortByLinkableAssociation
private Name name;
Really I didn't find a clear and success solution to this issue but decide to expose it to let think about it or even Spring team take in consideration to include at nexts releases.
Please see https://stackoverflow.com/a/66135148/6673169 for possible workaround/hack, when we wanted sorting by linked entity.
I seem to be baffled on how JPA Repositories are suppose to work.
In a nut-shell
#Entity
public class User extends AbstractEntity {
protected final static String FK_NAME = "USER_ID";
#Column(nullable = false)
private String firstName;
#OneToMany(cascade = ALL, fetch = FetchType.LAZY, orphanRemoval = true)
#JoinColumn(name = "userId")
private List<Detail> details = new ArrayList<Detail>();
}
#Entity
public class Detail extends AbstractEntity {
Long userId;
String hello;
}
#Repository
public interface UserRepository extends CrudRepository<User, Long> {
User findByFirstName(#Param("firstName") String firstName);
}
And here is the only controller in the app:
#RestController
public class Home {
#Autowired
UserRepository userRepository;
#Autowired
DetailsRepository loanRepository;
#RequestMapping(value = "")
public HttpEntity home() {
User user = userRepository.findByFirstName("John");
if (user == null) {
user = new User();
user.setFirstName("John");
}
Detail detail = new Detail();
detail.setHello("Hello Msh");
user.getDetails().add(detail);
userRepository.save(user);
return new ResponseEntity("hi", HttpStatus.OK);
}
}
Below a screenshot from debugging session where the app just started and the get request to home() method creates new user, new detail, adds detail to user.
Below example - when the user is saved, the detail entity gets updated
Now on the next request, the old user John is found and has been added a new instance of detail.
The old user has been saved but now the newly created detail does not get updated outside.
How come this only works first time ?
Basically theres so much fail going on so that I would advise you to go a step backwards. If youre wana go the short path of getting a solution for exactly this problem continue reading ;)
First part related to the answer of Jaiwo99:
As I can see in the gradle view of intellij, your using Spring Boot. So it is necessary to place #EnableTransactionManagement on top of your configuration class. Otherwise the #Transacion annotation does not have any effect.
Second part your JPA/Hibernate model mapping. Theres so much bad practise on the net that it is no wonder that most beginners have troubles starting with it.
A correct version could look like (not tested)
#Entity
public class User extends AbstractEntity {
#Column(nullable = false)
private String firstName;
#OneToMany(cascade = ALL, fetch = FetchType.LAZY, orphanRemoval = true, mappedBy="user")
private List<Detail> details = new ArrayList<Detail>();
public void addDetail(Detail detail) {
details.add(detail);
detail.setUser(user);
}
}
#Entity
public class Detail extends AbstractEntity {
#ManyToOne
private User user;
private String hello;
public void setUser(User user){
this.user = user;
}
}
Some general advice related to creating a model mapping:
avoid bi-directional mappings whenever possible
cascade is a decision made on the service level and not at the model level and can have huge drawbacks. So for beginners avoid it.
I have no idea why people like to put JoinColumn, JoinTable and whatever join annotation on top of fields. The only reason to do this is when you have a legacy db (my opinion). When you do not like the names created by your jpa provider, provide a different naming strategy.
I would provide a custom name for the user class, because this is in some databases a reserved word.
Very simple, the first time you saved a new entity outside of hibernate session, the second time, the user object you got is a detached object, by default hibernate will not consider it is changed in this case.
*solution *
Move this logic to another service class, which annotated with #transactional
Or
Annotate your controller with transactional
Or
Override equals and hashCode method on user class may also help
What I'm trying to do retrieve a user by their id and also retrieve the modules assigned to them on a page. I have mapped the one to many relationship in the models.
User Model
#Entity
#Table(name = "user")
#Component
public class User implements Serializable
#OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="user")
private Set<Module> sModule = new HashSet<Module>();
#OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="manager")
private Set<Module> cModule = new HashSet<Module>();
Module model
#Entity
#Table(name = "modules")
#Component
public class Module implements Serializable
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="user_id", insertable=false, updatable=false)
private User user;
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="manager_id", insertable=false, updatable=false)
private User manager;
Controller for it -
#RequestMapping(value="/home/user_page/{userId}", method =
RequestMethod.GET)
public String showUserModules(#PathVariable("userId") String userId, ModelMap
map, HttpServletRequest request) {
map.addAttribute("cp", request.getContextPath());
map.addAttribute("user", userService.getWithModules(userId));
return "/home/user_page";}
When I try to open the user_page it returns an error showing:
The requested resource is not available
So how do I get the user and the required modules for them when I go their user page.
Edit: Stacktrace
WARN : org.springframework.web.servlet.PageNotFound - No mapping found for HTTP
request with URI [/professional/home/user_page] in DispatcherServlet
with name 'servlet-context'
I think the problem in your case coused by similar mapping for two methods in controllers. As I understood one of the methods has mapping like "/home/user/setting_page" and another one "/home/user/{userId}". That's why after you have added userId path variable controller tries to parse "setting_page" as userId, and you get this error because such user doesn't exists. Try to change one of this URL in order to make them unique.
EDIT:
Ok. As I see from your updates the reason of the problem is that Spring tries to find mapping for url "home/user_page" but it can't because you don't have method with such mapping in controllers. If you want to display JSP (or html) as a result of this method call then you should define InternalViewResolver in your config file and return name of the page. Here is tutorial where among other described how to use InternalViewResolver.
I am trying to find a way to retrieve the auto generated Id of an entity that is persisted in the database via cascade. I am using Hibernate 4.1.9, Spring data 1.2 and Spring framework 3.2.1. Here are the entities in question : Location, Home, Room.
Location parent class
#Entity
#Table(name = "location")
#Inheritance(strategy = InheritanceType.JOINED)
public class Location implements Serializable
{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "location_id", unique = true)
private long uuid;
// other attributes and methods not relevant
}
Home class extending a Location, referencing a set of Rooms
#Entity
#Table(name = "home")
#Inheritance(strategy = InheritanceType.JOINED)
#PrimaryKeyJoinColumn(name = "home_id")
public class Home extends Location implements Serializable
{
#OneToMany(mappedBy = "containingHome", cascade = {CascadeType.ALL}, orphanRemoval = true)
private Set<Room> rooms;
// other attributes and methods not relevant
}
and finally the Room class referencing a Home object
#Entity
#Table(name = "room")
#PrimaryKeyJoinColumn(name = "room_id")
public class Room extends Location implements Serializable
{
#ManyToOne()
#JoinColumn(name = "home_id")
protected Home containingHome;
// other attributes and methods not relevant
}
I am using Spring data to create Repositories for the entities.
LocationRepository
public interface LocationRepository extends JpaRepository<Location, Long>
{ }
The problem I am having is that I need the id in order to be able to retrieve the different objects from the database and that is generated automatically. The only way I can access the id through the element is if I get the managed object when I save it to the database. But if I try to save each location in turn like so:
Home home = new Home();
home = locationService.save(home) // service that just calls locationRepository.save method
Room bedroom = new Room(home);
bedroom = locationService.save(bedroom);
I get a duplicate entry of room in the database which I think is related to a Hibernate issue https://hibernate.onjira.com/browse/HHH-7404. If I just call
Home home = new Home();
Room bedroom = new Room(home);
locationService.save(home)
there are no doubles but I have no way to retrieve the room object since it was persisted on cascade and its id is 0. Is there a way to solve this without introducing other fields in the location like a unique name that I have to generate myself? Any help is much appreciated.
Edit
If in the last case I have home = locationService.save(home) and then call home.getUuid() I get the right value which is normal I think since I retrieve a managed object. But if I do bedroom.getUuid() I get 0 since bedroom is not managed and so it has not had its id field updated with the value from the database.
Have you tried calling home.getUuid(); (assuming you have a getter for that field) after the persist call?
You might be surprised, but Hibernate (and JPA) will update the in memory copy with the id.
I'm using Spring 3.1.0.RELEASE with Hibernate 4.0.1.Final. I want to invoke a search method in a controller that takes as input a search bean (the Event bean below) ...
#RequestMapping(value = "/search_results.jsp")
public ModelAndView processSearch(final HttpServletRequest request, final Event searchBean, final BindingResult result) {
...
}
The event bean contains the following field ...
#Entity
#Table(name = "EVENTS")
public class Event implements Comparable {
...
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name="EVENT_FEED_ID")
private EventFeed eventFeed;
...
}
in which the EventFeed object contains the following fields ...
#Entity
#Table(name = "EVENT_FEEDS")
public class EventFeed {
#Id
#Column(name = "ID")
#GeneratedValue(strategy=GenerationType.AUTO)
private Integer id;
#NotEmpty
#Column(name = "TITLE")
private String title;
...
}
How do I construct a URL such that the search bean's Event.getEventFeed().getId() field is populated?
I realize I could submit a GET request with a parameter like "eventFeedId=2" and populate everything manually, but since other pages are submitting requests that populate the command object, I'd like to continue to use the same logic.
It would be
/search_results.jsp?event.eventFeed.id=...&event.eventFeed.title=...
event is a default model attribute name as defined in #ModelAttribute, other binding rules are described in 5.4.1 Setting and getting basic and nested properties.
Note, however, that this approach can cause problems if you'll associate these bean with Hibernate session later. For example, if you want to attach new Event to the existing EventFeed by calling merge() it would also override the title property. Thus, in such a case it would be better to avoid overuse of data binding and pass primitives as parameters instead.