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Spring DATA - How to load a Collections of ids for an ManyToMany relation without load the whole LazyProxyObject [duplicate]

I have two Entities in my Spring-Boot Application:
User.java
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
Long id;
String firstname;
String lastname;
String username;
String password;
}
and
Role.java
Entity
#Table(name = "role")
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
Long id;
String name;
String description;
}
for my MySql database
I have excluded the getter and setter methods for this question.
I want to realise a Many-to-Many-Relationship between both Entities. Every user should be able to assign multiple roles to himself
I already Created a mapping table for both tables in my database. It has the rows
user_id
role_id.
I also created a new Entity UserRole.java which looks like this:
#Entity
#Table(name = "user_role")
public class UserRole implements Serializable{
private User user;
private Role role;
#Id
#ManyToOne
#JoinColumn(name = "user_id")
public User getuser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
#Id
#ManyToOne
#JoinColumn(name = "role_id")
public Role getrole(){
return role;
}
public void setRole(Role role){
this.role = role;
}
}
Now my question: is this construction correct? If yes, how do i add existing roles to an existing user and get the roles of this user in spring-boot?

You can find any tutorial connected with many-to-many relationship using Hibernate/Spring Data, example:
Spring Data many-to-many
With your model it's simple to add the relationship mappings, like this:
#Entity
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
private String description;
#ManyToMany(cascade = CascadeType.ALL)
#JoinTable
private Set<User> users;
}
and this:
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String firstname;
private String lastname;
private String username;
private String password;
#ManyToMany(mappedBy = "users")
private Set<Role> roles;
}

Java JPA Realtions

I am doing an application where I need 2 entities: User and Car.
public class User{
private long id;
private String name;
}
public class Car{
private long id;
private User firstUser;
private User secondUser;
}
So my table cars_info info will contain
RENT(date), FIRST_USER(id), SECOND_USER(id)
How do I connect this using hibernate? I need unidirectional relation. I tried OneToOne, ManyToOne but neither of that works.

Check that you're properly naming the column on your CAR table vs the reference column on the USER table. Example below:
#Entity
#Table(name = "USER")
public class User {
#Id
#Column(name = "USER_ID")
private long id;
#Column(name = "NAME")
private String name;
}
#Entity
#Table(name = "CAR")
public class Car {
#Id
#Column(name = "CAR_ID")
private long id;
#ManyToOne
#JoinColumn(name = "FIRST_USER_ID", referencedColumnName = "USER_ID")
private User firstUser;
#ManyToOne
#JoinColumn(name = "SECOND_USER_ID", referencedColumnName = "USER_ID")
private User secondUser;
}

#OneToOne Hibernate with annotations. Can't properly save

I can't make my foreign keys auto generate using hibernate and jpa with annotations. Everything seems ok, The entries are saved in database. All the date come from one form which, when submited creates an User object with ModelAttribute and then saves it in Database.
Here are my beans. Anything else i should add ?
#Entity
#Table(name="adress")
public class Adress implements Serializable {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name="adress_id")
private Integer adressId;
#NotBlank(message="The city must be completed")
#Column(name="city")
#Size(min=5,max=30)
private String city;
#NotBlank(message="The street must be completed")
#Column(name="street")
#Size(min=5,max=30)
private String street;
#NotNull(message="The street number must be completed")
#NumberFormat
#Column(name="street_no")
private Integer streetNo;
#OneToOne
#JoinColumn(name="user_id")
private User user;}
and the other one:
#Entity
#Table(name="users")
public class User implements Serializable {
#Id
#Column(name="user_id")
#GeneratedValue(strategy=GenerationType.AUTO)
private Integer userId;
#NotBlank(message="Username can't be blank")
#Size(min=5,max=30)
#Column(name="username")
private String username;
#NotBlank(message="Password field can't be blank")
#Size(min=5,max=30)
#Column(name="password")
private String password;
#NumberFormat
#NotNull(message="Age field must not be blank")
#Column(name="age")
private Integer age;
#Column(name="message")
#Size(min=0,max=100)
private String message;
#Column(name="date")
#DateTimeFormat(pattern="dd/mm/yyyy")
private Date dateCreated;
#OneToOne(mappedBy="user",cascade=CascadeType.ALL,fetch=FetchType.EAGER)
private Adress adress;
+getters and setters for them
public void save(T entity){
sessionFactory.getCurrentSession().save(entity);
}

If I understand you correctly and you're trying to get Hibernate to set the foreign key on your related record this might help. Try getting rid of mappedBy and instead specify the JoinColumn. This works for me on a one to many:
The order:
#Entity
#Table(name = "`order`")
public class Order implements Serializable {
#Id
#GeneratedValue
private Long id;
// Order columns...
#OneToMany(cascade = CascadeType.ALL)
#JoinColumn(name = "order_id")
private Set<Item> items;
}
The item:
#Entity
#Table(name = "item")
public class Item implements Serializable {
#Id
#GeneratedValue
private Long id;
// Item columns...
#ManyToOne(optional = false)
#JoinColumn(name = "order_id", referencedColumnName = "id", nullable = false)
private Order order;
}

in adress class
#OneToOne(mappedBy="adress")
private User user;
and in user class
#OneToOne(cascade=CascadeType.ALL,fetch=FetchType.EAGER,optional=false)
#PrimaryKeyJoinColumn
private Adress adress;

Hibernate Relationship Mapping Issue

Hibernate novice here, running into issues trying to properly map the relationships between my Hibernate Entity classes.
I have a Ticket Entity and a User Entity. A user has many tickets, but a ticket only belongs to one unique user. What i've done is mapped the User - Tickets as a #OneToMany relationship and the Tickets - User as a #ManyToOne relationship. However, I am not getting any tickets returned.
The Query Hibernate is running is:
Hibernate: select tickets0_.user_user_id as user1_1_3_, tickets0_.tickets_ticket_id as tickets2_3_, ticketenti1_.ticket_id as ticket1_0_0_, ticketenti1_.assigned_to_user_id as assigned7_0_0_, ticketenti1_.belongs_to_user_id as belongs8_0_0_, ticketenti1_.date_created as date2_0_0_, ticketenti1_.description as descript3_0_0_, ticketenti1_.status_id as status4_0_0_, ticketenti1_.title as title0_0_, ticketenti1_.urgency_id as urgency6_0_0_, userentity2_.user_id as user1_1_1_, userentity2_.email as email1_1_, userentity2_.firstname as firstname1_1_, userentity2_.lastname as lastname1_1_, userentity2_.password as password1_1_, userentity2_.role_id as role6_1_1_, userentity2_.username as username1_1_, userentity2_.verified as verified1_1_, userentity3_.user_id as user1_1_2_, userentity3_.email as email1_2_, userentity3_.firstname as firstname1_2_, userentity3_.lastname as lastname1_2_, userentity3_.password as password1_2_, userentity3_.role_id as role6_1_2_, userentity3_.username as username1_2_, userentity3_.verified as verified1_2_ from user_ticket tickets0_ inner join ticket ticketenti1_ on tickets0_.tickets_ticket_id=ticketenti1_.ticket_id left outer join user userentity2_ on ticketenti1_.assigned_to_user_id=userentity2_.user_id left outer join user userentity3_ on ticketenti1_.belongs_to_user_id=userentity3_.user_id where tickets0_.user_user_id=?
The Entity Classes are:
TicketEntity.java
#Entity
#Table(name="ticket")
public class TicketEntity {
#Id
#Column(name="ticket_id")
#GeneratedValue(strategy=GenerationType.AUTO)
private int id;
#Column(name="title")
private String title;
#Column(name="description")
private String description;
#Column(name="date_created")
#Temporal( TemporalType.TIMESTAMP )
private Date date_created;
#Column(name="status_id")
private int status_id;
//private TicketStatus status;
#Column(name="urgency_id")
private int urgency_id;
#ManyToOne
#JoinColumn(insertable=false, updatable=false)
private UserEntity belongs_to;
#ManyToOne
#JoinColumn(insertable=false, updatable=false)
private UserEntity assigned_to;
UserEntity.java
#Entity
#Table(name="user")
public class UserEntity {
#Id
#Column(name="user_id")
#GeneratedValue(strategy=GenerationType.AUTO)
private int id;
#Column(name="firstname")
private String firstname;
#Column(name="lastname")
private String lastname;
#Column(name="username")
private String username;
#Column(name="email")
private String email;
#Column(name="password")
private String password;
#Transient
private String confirmpassword;
#Column(name="verified")
private boolean verified;
#Column(name="role_id")
private int role_id;
#OneToMany(fetch = FetchType.EAGER)
private List<TicketEntity> tickets;
Any help is appreciated,
Thanks!

In UserEntity.java, you need to add "mappedBy" for List<TicketEntity> tickets, like this:
#OneToMany(fetch = FetchType.EAGER, mappedBy="belongs_to")//why you have two UserEntity in TicketEntity.java?
private List<TicketEntity> tickets;
In TicketEntity.java, add (name = "user_id") to #JoinColumn for UserEntity belongs_to, like this:
#ManyToOne
#JoinColumn(name = "user_id", insertable=false, updatable=false)
private UserEntity belongs_to;
Same for private UserEntity assigned_to. You may need add another list for it in UserEntity.java if you want to query it too.

Retrieve logged user object and save it as a foreign key

While saving some data from the form I also need to add FK to the Record table. FK is User.Id.
I know how to save data from the input field on the form, but how can I set FK (int value) to this:
#ManyToOne
#JoinColumn(name = "id")
#Cascade({CascadeType.ALL})
private User user;
Is there some way to retrieve object which relates to logged user and make something like this: record.setUser(user)?
I've googled it but I didn't manage to find how to achive this.
This is my entity class.
#Entity
public class Record implements java.io.Serializable{
#Id
#GeneratedValue
private int recordId;
private String recordName;
private String recordComment;
private Date recordDate;
private Integer price;
#ManyToOne
#JoinColumn(name = "userId", insertable = true, updatable = false)
#Cascade({CascadeType.ALL})
private User user;
......
}
#Entity
#Table(name = "system_user")
public class User implements java.io.Serializable{
#Id
#GeneratedValue
private int userId;
#NotEmpty
#Email
private String email;
#Size(min=2, max=30)
private String name;
private String enabled;
#NotEmpty
private String password;
private String confirmPassword;
#Enumerated(EnumType.STRING)
#Column(name = "user_role")
private Role role;
#OneToMany(fetch = FetchType.EAGER,mappedBy = "user", orphanRemoval=true)
#Cascade({CascadeType.ALL})
private List<Record> records;
public void addToRecord(Record record) {
record.setUser(this);
this.records.add(record);
}
....
}
This is how I save data to DB:
#RequestMapping(value = "/protected/add", method = RequestMethod.POST)
public String addCost (#ModelAttribute("record") Record record,HttpSession session){
User user = userManager.getUserObject(userManager.getUserId(session.getAttribute("currentUser").toString()));
user.addToRecord(record);
recordService.addRecord(record);
return "redirect:/protected/purse";
}
DAO:
public void addRecord(Record record) {
sessionFactory.getCurrentSession().save(record);
}
UPDATE: problem was partially solved, code above works fine for me.

You also need to create User object and set the user object in a Record object using the below code
record.setUser(userObj);
and user foreign key will be automatically saved in database.