[Spring MVC] Login Bean

package com.spring.controller;
 
public class LoginBean {
 
    private String userName;
    private String password;
 
    public String getUserName() {
        return userName;
    }
 
    public void setUserName(String userName) {
        this.userName = userName;
    }
 
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
}

    @RequestMapping(method = RequestMethod.POST)
    public String submit(Model model, @ModelAttribute("loginBean") LoginBean loginBean) {
        if (loginBean != null && loginBean.getUserName() != null & loginBean.getPassword() != null) {
            if (loginBean.getUserName().equals("chandra") && loginBean.getPassword().equals("chandra123")) {
                model.addAttribute("msg", "welcome" + loginBean.getUserName());
                return "success";
            } else {
                model.addAttribute("error", "Invalid Details");
                return "login";
            }
        } else {
            model.addAttribute("error", "Please enter Details");
            return "login";
        }
    }
}

public class User {
    @Id
    @GeneratedValue
    @Column(name = "id")
    private int id;
 
    @Column(name = "email")
    private String email;
 
    @Column(name = "full_name")
    private String fullName;
 
    @Column(name = "username")
    private String username;
 
    @Column(name = "password")
    private String password;
 
    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinTable(name = "user_roles", joinColumns = @JoinColumn(name = "user_id"),
            inverseJoinColumns = @JoinColumn(name = "role_id"))
    private Set<Role> roles = new HashSet<>();
 
    ...
}