How to assign default Role to user upon registration in Spring Boot? - spring-boot

Question

I'm learning Spring Boot security, I am trying to figure out how to properly implement authorization but each resource I find uses InMemory data to show it. However, I want to use User data that is entered from a registration form that is stored in the DB and give each user a default role of ROLE_USER.
User Model
#Entity
#Data
#NoArgsConstructor
#AllArgsConstructor
#Table(name = "users")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long Id;
private String firstname;
private String lastname;
private String username;
private String email;
private String password;
#ManyToMany(cascade = {CascadeType.ALL}, fetch = FetchType.EAGER)
#JoinTable(
name = "user_role",
joinColumns = {#JoinColumn(name = "user_id")},
inverseJoinColumns = {#JoinColumn(name = "role_id")}
)
#Enumerated(EnumType.STRING)
Set<Role> roles = new HashSet<>();
}
Role Model
#Entity
#Data
#NoArgsConstructor
#AllArgsConstructor
#Table(name = "roles")
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#Enumerated(EnumType.STRING)
#Column(length = 20)
private RoleName name;
}
Role Enum
public enum RoleName {
ROLE_ADMIN,
ROLE_USER,
ROLE_EMPLOYEE;
}
PostMapping Method that saves user to DB
#PostMapping(value="users/addNew")
public RedirectView addNew(User user, RedirectAttributes redirect, Model model) throws QrGenerationException {//Controller used to add new user to database(Register new user)
Role role = new Role();
role.setName(RoleName.ROLE_USER);
roleRepository.save(role);
user.setRoles(new HashSet<>(Collections.singletonList(role)));
userService.save(user);
RedirectView redirectView= new RedirectView("/login",true);//After successful registration user is redirected to the login page
redirect.addFlashAttribute("message", "You successfully registered! You can now login");
return redirectView;
}
And this is the Registration form
<form class="login-form" th:action="#{/users/addNew}" method="post">
<div class="login-wrap">
<p class="login-img"><i class="icon_lock_alt"></i></p>
<div class="form-group">
<span class="input-group-addon"><i class="icon_profile"></i></span>
<input type="text" class="form-control" placeholder="Firstname" autofocus name="firstname">
</div>
<div class="form-group">
<span class="input-group-addon"><i class="icon_profile"></i></span>
<input type="text" class="form-control" placeholder="Lastname" autofocus name="lastname">
</div>
<div class="form-group">
<span class="input-group-addon"><i class="icon_profile"></i></span>
<input type="text" class="form-control" placeholder="Username" autofocus name="username">
</div>
<div class="form-group">
<span class="input-group-addon"><i class="icon_profile"></i></span>
<input type="text" class="form-control" placeholder="Email" name="email" autofocus>
</div>
<div class="form-group">
<span class="input-group-addon"><i class="icon_key_alt"></i></span>
<input type="password" class="form-control" placeholder="Password" id="password" name="password">
</div>
<div class="form-group">
<span class="input-group-addon"><i class="icon_key_alt"></i></span>
<input type="password" class="form-control" placeholder="Confirm Password" id="confirmPassword">
</div>
<label class="checkbox">
<span><a th:href="#{/login}"> Login Page</a></span>
<span class="pull-right"> <a th:href="#{/forgot-password}"> Forgot Password?</a></span>
</label>
<button class="btn btn-primary btn-lg btn-block" type="submit">Register</button>
</div>
</form>
So far I have tried giving each new user upon registration a default Role of User or ROLE_USER which is an enum with the following code
Role role = new Role();
role.setName(RoleName.ROLE_USER);
roleRepository.save(role);
user.setRoles(new HashSet<>(Collections.singletonList(role)));
userService.save(user);
When I use this method, a Role Id and RoleName is stored in the Role table (Which I don't think should be):
I want the User Id and the Role name to be stored in the user_role table.
I'm trying to ask the question properly but I'm new to Authorization in Spring Boot and don't yet full understand how it works.