How to get rid of "Could not write JSON: failed to lazily initialize a collection of role" if i have #Transactional and JOIN FETCH? - spring

Question

I have Rest #GetMapping method :
#GetMapping(value = "/getAdmin",produces = "application/json")
public List<Users> listOfUsers(){
return userService.findAllUsers();
}
findAllUsers function looks like :
#Override
#Transactional
public List<Users> findAllUsers() {
String hqlRequest = "from Users U JOIN FETCH U.roles";
Query query = sessionFactory.getCurrentSession().createQuery(hqlRequest);
}
That is, JOIN FETCH works fine if i just call:
List<Users> users = userService.findAllUsers();
System.out.println(users);
but when a request is sent to the listOfUsers method, I get an error:
Could not write JSON: failed to lazily initialize a collection of role
I have read solutions to this problem and there it is advised to add the #Transaction annotation or use joint fetch in the request, but I have both, but I still get an error.Can someone explain how to get rid of this error and?
Users
package com.example.securityWithHibernate.Model;
import org.hibernate.validator.constraints.Length;
import javax.persistence.*;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import java.util.Set;
#Entity
#Table(name = "users")
public class Users {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
#Length(min = 5, message = "*Your user name must have at least 5 characters")
#NotEmpty(message = "*Please provide a user name")
private String name;
#Column(name = "first_name")
#NotEmpty(message = "*Please provide your name")
private String firstName;
#Column(name = "last_name")
#NotEmpty(message = "*Please provide your last name")
private String lastName;
#Column(name = "email")
#Email(message = "*Please provide a valid Email")
#NotEmpty(message = "*Please provide an email")
private String email;
#Column(name = "user_password")
#Length(min = 5, message = "*Your password must have at least 5 characters")
#NotEmpty(message = "*Please provide your password")
private String userPassword;
public Set<Roles> getRoles() {
return roles;
}
public void setRoles(Set<Roles> roles) {
this.roles = roles;
}
#ManyToMany(fetch = FetchType.LAZY)
#JoinTable(name = "user_roles",
joinColumns = #JoinColumn(name = "user_id"),
inverseJoinColumns = #JoinColumn(name = "role_id")
)
private Set<Roles> roles;
public Users(Long id, String name, String firstName, String lastName, String email, String userPassword) {
this.id = id;
this.name = name;
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
this.userPassword = userPassword;
}
/*public Users( String name, String firstName, String lastName, String email, String userPassword) {
this.name = name;
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
this.userPassword = userPassword;
}*/
public Users() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getUserPassword() {
return userPassword;
}
public void setUserPassword(String userPassword) {
this.userPassword = userPassword;
}
#Override
public String toString() {
return "Users{" +
"id=" + id +
", name='" + name + '\'' +
", firstName='" + firstName + '\'' +
", lastName='" + lastName + '\'' +
", email='" + email + '\'' +
", userPassword='" + userPassword + '\'' +
", roles=" + roles +
'}';
}
}
Roles
package com.example.securityWithHibernate.Model;
import javax.persistence.*;
import java.util.Set;
#Entity
#Table(name = "roles")
public class Roles {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;
public Roles(Long id, String role) {
this.id = id;
this.role = role;
}
public Roles() {
}
#Column(name = "role_name")
private String role;
#ManyToMany(mappedBy = "roles")
private Set<Users> users;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
public Set<Users> getUsers() {
return users;
}
public void setUsers(Set<Users> users) {
this.users = users;
}
#Override
public String toString() {
return "Roles{" +
"id=" + id +
", role='" + role + '\'' +
'}';
}
}