QueryDsl MongoDb Relation - spring

I am trying to use Mongodb with spring-data and QueryDsl.
I have following entitys:
#QueryEntity
#Document(collection="groups")
public class GroupImpl implements Group {
private String name;
#DBref
private List<User> groupMembers;
and
#QueryEntity
#Document(collection="users")
public class UserImpl implements User{
public static final String FIRST_NAME = "firstName";
public static final String LAST_NAME = "lastName";
My Repositories are implemented like this:
public interface GroupRepository extends Repository<Group, String>,QueryDslPredicateExecutor<Group>{}
Every normal CRUD operations were running successfully.
Also operations like "getUserByEmail" etc working successfully.
Now I am trying to get all Groups of an User in a UnitTest.
#Before
public void setup(){
roles = Arrays.asList(new String[]{"admin","user","guest"});
user = new UserImpl();
user.setFirstName("Foo");
user.setLastName("Bar");
user.setShortname("fbar");
user.setEMail("foo#bar.com");
user.setRoles(roles);
user2 = new UserImpl();
user2.setFirstName("Foo");
user2.setLastName("Bar");
user2.setShortname("fbar");
user2.setEMail("foo#bar.com");
user2.setRoles(roles);
user = userRepository.save(user);
user2 = userRepository.save(user2);
group = new GroupImpl();
group.setGroupMembers(Arrays.asList(new User[]{user,user2}));
group.setName("testGroup2");
group2 = new GroupImpl();
group2.setGroupMembers(Arrays.asList(new User[]{user,user2}));
group2.setName("testGroup2");
}
#Test
public void findGroupsByUser(){
Group savedGroup = repository.save(group);
Group savedGroup2 = repository.save(group2);
Assert.assertTrue(savedGroup2.getGroupMembers().contains(user));
List<Group> foundGroup = (List<Group>)repository.findAll(QGroupImpl.groupImpl.groupMembers.contains(user));
Assert.assertNotNull(foundGroup);
Assert.assertEquals(2, foundGroup.size());
}
This test fails "expected:<2> but was:<0>"
I am confused because savedGroup2 contains the user but if I try to get all Groups with this groupmember using QueryDsl I get no result.
I already checked the database and the users are stored successfully.
I also debugged and checked if the "_id"s of the given user and the user in the database are equal.
I have no Idea whats wrong.

Related

Spring boot hibernate #ManyToMany doesn't commit or returns incomplete data when I execute any method on the junction table from non-owner entity

I'm currently working on a Spring Boot project for an online shop. It's my first project with Spring Boot (and my first post here), so my coding is not the best.
Context for the questions:
My shop (for now) has a lists of products and whishlists of different users (shopping lists), which have a bidirectional #ManyToMany relation (i left here the relevant details for my question(s)):
Product.java entity:
#Entity
public class Product extends RepresentationModel\<Product\>{
#Id
#GeneratedValue
#JsonView(ProductView.DescriptionExcluded.class)
private Integer id;
#ManyToMany()
#JoinTable(
name = "Shopping_Product",
joinColumns = { #JoinColumn(name = "id", referencedColumnName = "id") },
inverseJoinColumns = { #JoinColumn(name = "list_id", referencedColumnName = "list_id") })
#JsonIgnore
private Set<ShoppingList> shoppinglists = new HashSet<>();
// Constructor, getters, setters ....
ShoppingList.java entity:
#Entity
public class ShoppingList {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#JsonView(ShoppingListView.ProductsExcluded.class)
private Integer list_id;
#JsonView(ShoppingListView.ProductsIncluded.class)
#ManyToMany(mappedBy = "shoppinglists")
private Set<Product> products = new HashSet<>();
// Constructor, getters, setters ...
I chose Product as the owner because i wanted to delete (tho it would be more fit to show something like "offer expired", but I'll stick to delete for now) the product from all existing lists when the admin takes it down from the shop, which works as expected:
ProductResource.java (controller):
#DeleteMapping("/categs/*/sub/*/products/{id}")
public ResponseEntity<String> deleteProduct(#PathVariable int id) {
Optional<Product> optional = productRepository.findById(id);
if(!optional.isPresent()) throw new NotFoundException("Product id - " + id);
Product prod = optional.get();
productRepository.delete(prod);
return ResponseEntity.ok().body("Product deleted");
}
My problems now are related to the ShoppingList entity, which is not the owner.
Any call I make to the Product resource (controller) works as expected, but anything from the other side either fails or returns incomplete results, like the following:
1.
I call retrieve all products from a list and it returns only the first object (the list has at least 2):
ShoppingListResource.java (controller):
#RestController
public class ShoppingListResource {
#Autowired
private ProductRepository productRepository;
#Autowired
private UserRepository userRepository;
#Autowired
private ShoppingListRepository shoppinglistRepository;
#GetMapping("/user/lists/{id}")
public Set<Product> getShoppinglistProducts(#PathVariable int id) {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
String currentPrincipalName = authentication.getName();
ShoppingList shoppingList = shoppinglistRepository.findById(id).get();
String name = shoppingList.getUser().getUsername();
if(!Objects.equals(currentPrincipalName, name)) throw new IllegalOperation("You can only check your list(s)!");
// All lists are shown for a product
// Product p = productRepository.findById(10111).get();
// Set<ShoppingList> set = p.getShoppinglists();
// set.stream().forEach(e -> log.info(e.toString()));
// Only first product is shown for a list
return shoppingList.getProducts();
This is what hibernate does on the last row (only returns 1/2 products)
Hibernate: select products0_.list_id as list_id2_3_0_,
products0_.id as id1_3_0_,
product1_.id as id1_1_1_,
product1_.description as descript2_1_1_,
product1_.name as name3_1_1_,
product1_.price as price4_1_1_,
product1_.subcat_id as subcat_i5_1_1_ from shopping_product products0_ inner join product product1_ on products0_.id=product1_.id where products0_.list_id=?
As i said above, I can delete a product and it gets removed automatically from all existing lists, but when i try the same from ShoppingList entity does nothing:
Same controller
#DeleteMapping("/user/lists/{id}")
public ResponseEntity<String> deleteShoppinglist(#PathVariable int id) {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
String currentPrincipalName = authentication.getName();
ShoppingList shoppingList = shoppinglistRepository.findById(id).get();
String name = shoppingList.getUser().getUsername();
if(!Objects.equals(currentPrincipalName, name)) throw new IllegalOperation("You can only delete your list(s)!");
shoppinglistRepository.delete(shoppingList);
return ResponseEntity.ok().body("Shopping list deleted");
}
Also, when i try to add/delete product from an existing list, does nothing.
This is my repo with full code, if you'd like to test directly (dev branch is up to date):
https://github.com/dragostreltov/online-store/tree/dev
You can just use admin admin as authentication (on the H2 console too). More details on the readme.
All DB data at app start is inserted from a .sql file.
I checked other similar questions and tried different methods on my ShoppingList entity (on the delete issue), like:
#PreRemove
public void removeListsFromProducts() {
for(Product p : products) {
p.getShoppinglists().remove(this);
}
}
Spring/Hibernate: associating from the non-owner side
And still doesn't work.
UPDATE:
I found out what issues I was having, I'll post an answer with the solution.
For anyone who's got the same/similar problems as I did, this is how I resolved them:
For point 1
(Hibernate only retrieves the first product from a shoppingList (Set))
I made multiple tests on my retrieve method and found out my Set was only containing 1 object, despite calling .add(product) twice.
As you can see, I'm using HashSet for both entities:
In Product (owner):
private Set<ShoppingList> shoppinglists = new HashSet<>();
In ShoppingList (mappedBy):
private Set<Product> products = new HashSet<>();
Thanks to this answer: https://stackoverflow.com/a/16344031/18646899
I learnt:
HashSet (entirely reasonably) assumes reflexivity, and doesn't check for equality when it finds that the exact same object is already in the set, as an optimization. Therefore it will not even call your equals method - it considers that the object is already in the set, so doesn't add a second copy.
In particular, if x.equals(x) is false, then any containment check would also be useless.
Taking this into account, I overwrote the hashCode() and equals() methods in Product.class and now
shoppingList.getProducts()
works as expected.
For point 2
(not being able to delete associations of non-owner entity before deleting the row from it's table)
Added lazy fetch and cascade to Product #ManyToMany:
#ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.DETACH})
And added the following methods:
In Product class:
public void addShoppinglist(ShoppingList list) {
this.shoppinglists.add(list);
list.getProducts().add(this);
}
public void removeShoppinglist(ShoppingList list) {
this.shoppinglists.remove(list);
list.getProducts().remove(this);
}
In ShoppingList class:
public void addProduct(Product product) {
this.products.add(product);
product.getShoppinglists().add(this);
}
public void removeProduct(Product product) {
this.products.remove(product);
product.getShoppinglists().remove(this);
}
Added #Transactional and modified the method inside the controller (ShoppingListResource) for deleteShoppingList:
#RestController
public class ShoppingListResource {
...
#Transactional
#DeleteMapping("/user/lists/{id}")
public ResponseEntity<String> deleteShoppinglist(#PathVariable int id) {
...
shoppingList.getProducts().stream().forEach(e -> {
e.removeShoppinglist(shoppingList);
});
shoppinglistRepository.delete(shoppingList);
return ResponseEntity.ok().body("Shopping list deleted");
}
}
And now this is working as expected, the shoppingList's associations are deleted first then the shoppingList itself.

Foreign Key/DBRef in Spring Data Firestore

I have 2 entities:
1- User:
#Document(collectionName = CollectionConstants.USER_COLLECTION)
public class User {
#DocumentId
protected String id;
private String username;
}
2- Contest:
#Document(collectionName = CollectionConstants.CONTEST_COLLECTION)
public class Contest {
private List<User> contestants;
}
How can I save only the ID of the user (whether it's a list of users, or a single user) in the database while letting Spring Data manage that automatically?
I'm actually looking for an alternative for the following:
Spring Data JPA: #OneToMany, #ManyToOne
Spring Data MongoDB: #DBRef
I have checked in the Spring Cloud GCP for Firestore, and it states:
The starter automatically configures and registers a Firestore bean in the Spring application context. To start using it, simply use the #Autowired annotation.
#Autowired
Firestore firestore;
void writeDocumentFromObject() throws ExecutionException, InterruptedException {
// Add document data with id "joe" using a custom User class
User data = new User("Joe",
Arrays.asList(
new Phone(12345, PhoneType.CELL),
new Phone(54321, PhoneType.WORK)));
// .get() blocks on response
WriteResult writeResult = this.firestore.document("users/joe").set(data).get();
LOGGER.info("Update time: " + writeResult.getUpdateTime());
}
User readDocumentToObject() throws ExecutionException, InterruptedException {
ApiFuture<DocumentSnapshot> documentFuture =
this.firestore.document("users/joe").get();
User user = documentFuture.get().toObject(User.class);
LOGGER.info("read: " + user);
return user;
}
There is sample https://github.com/spring-cloud-gcp/spring-cloud-gcp-samples/spring-cloud-gcp-firestore-sample

Insert nested records to mongo in reactive fashion

Trying to wrap my head around the reactor model and pipeline, I want to insert to mongo a couple of Users, then for each user I would like to insert several (10) Offers
My current implementation include inserting 3 users to the database, block and insert the offers (only for 1 user) in a somewhat backward way, like so
Flux.just(u1, u2, u3).flatMap(u -> reactiveMongoTemplate.insert(u)).blockLast();
Arrays.asList(u1, u2, u3).forEach(user -> {
IntStream.range(0,10).forEach(i -> reactiveMongoTemplate.insert(new Offer(user)).subscribe());
});
The first line run fine, but I get the following exception
java.lang.IllegalStateException: state should be: open
Of course I can bypass this by inserting for each user separately, I don't know why this exception was raised and appreciate an answer about this issue as well
My main question is how to write it in the most reactive way, should I need to block in order to populate the entity Id after insert or there is a better way?
The exact implementation of User and Offer doesn't really matter, it can be a any simple records, but here they are
#Data
#AllArgsConstructor
#NoArgsConstructor
#Document(collection = "users")
public class User extends BaseEntity {
private String name;
}
...
#Data
#Document(collection = "offers")
public class Offer extends BaseEntity {
private String title;
#JsonSerialize(using = ToStringSerializer.class)
private ObjectId user;
public Offer(){
this.title = "some title " + new Random().nextInt(10);
}
public Offer(User user){
this();
this.user = new ObjectId(user.getId());
}
public void setUser(String userId) {
this.user = new ObjectId(userId);
}
}
reactiveMongoTemplate is from spring-boot-starter-data-mongodb-reactive #EnableReactiveMongoRepositories
Thx
Turn out I was pretty close to the correct solution
Flux.just(u1, u2, u3).flatMap(u -> reactiveMongoTemplate.insert(u)).subscribe(u -> {
Flux.range(0,10).flatMap(i -> reactiveMongoTemplate.insert(new Offer(u))).subscribe();
});
now the code is truly reactive and it can be seen on the database as well (records are inserted with random order)

Externalize mongo json query using spring boot

I have just started using spring data MongoDb with Spring-Boot.
I have some mongo based json queries added in the interface using #query annotation when using spring data repository.
I want to know if it is possible to externalize or separate out the JSON query outside the codebase so that it can be optimized separately and
also not having it mixed with code.
Thanks for your suggestions.
This is the code which i have added in my interface and annotated with #query annotation.
#Query("{ 'firstname' : ?0 ,'lastname': ?1}")
List findByCriteria(String firstname,String lastname);
The above is a simple example. I have complex conditions involving $and and $or operators too .
What i basically want to achieve is externalize the above native mongo json query to a config file and refer that in the above annotation.
Spring data supports something similar when using jpa with hibernate. But not sure if we can do the same using spring data mongodb with spring boot.
Do like this (I am explaining only for the API)
Suppose you have an Entity user
At the Top there will be User domain
public class User extends CoreDomain {
private static final long serialVersionUID = -4292195532570879677L;
#Length(min = 2)
private String name;
#Length(min = 2)
#UniqueUserName(message = "User name already registered,Please choose something Different")
private String userName;
#Length(min = 6)
private String password;
}
User Controller
User Service (Interface)
User ServiceImpl(Service Implementation)
Mongo Repository(Since, I have MongoDb)
Now in userController you will take all the queries , Param(Parameters) , Pagerequest like this
public class UserController extends CoreController {
#Autowired
private UserService userService;
/*
* This controller is for getting the UserDetails on passing the UserId in
* the #param Annotation
*/
#GET
#Path("{id}")
public User getUser(#PathParam("id") String UserId) {
User user = new User();
user = userService.findUserId(UserId);
if (user == null)
throw new NotFoundException();
log.info("The userId you searched is having the details as :" + user);
return user;
}}
For serviceInterface you will have :
public interface UserService {
// Boolean authenticateUser(User user);
User findUserId(String UserId);
}
For serviceImpl :
public class UserServiceImpl implements UserService {
#Setter
#Autowired
private UserRepository userRepository;
/*
* This method will find user on the basis of their userIds passed in the
* parameter.
*/
#Override
public User findUserId(String UserId) {
User userIdResult = userRepository.findOne(UserId);
log.info("The userDetail is" + userIdResult);
return userIdResult;
}
In mongoRepository for user we will have:
A default query findById(String userId);
Hopefully this will help you.

Spring Repository issue

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

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