User Entity
@Entity
    public class User {
        @Id
        @Email
        @NotEmpty
        @Column(unique = true)
        private String email;
        @NotEmpty
        private String name;
        @Size(min=4)
        private String password;
        @OneToMany(mappedBy = "user",cascade = CascadeType.ALL)
        private List<Task> tasks;
        @ManyToMany(cascade = CascadeType.ALL)
        @JoinTable(name="USER_ROLES",joinColumns = {
                @JoinColumn(name="USER_EMAIL",referencedColumnName = "email")
        },inverseJoinColumns = {@JoinColumn(name="ROLE_NAME",referencedColumnName = "name")})
        private List<Role> roles;
        public String getEmail() {
            return email;
        }
        public void setEmail(String email) {
            this.email = email;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
        public List<Task> getTasks() {
            return tasks;
        }
        public void setTasks(List<Task> tasks) {
            this.tasks = tasks;
        }
        public List<Role> getRoles() {
            return roles;
        }
        public void setRoles(List<Role> roles) {
            this.roles = roles;
        }
How can I make this edit controller method work? Is it even possible to change the Id of the Entity? I have an HTML form and want to update email and password trough it.
@GetMapping(value = "/admin/setDetails")
public String editUser(@RequestParam("email") String email, Model model){
    User user = userService.findOne(email);
    model.addAttribute("user",user);
    return "setdetails";
}
I also tried to do it with userRepository.save(user) but whenever I edited email it makes new user and whenever I changed password I could not log in anymore with any password.
 
     
    