<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>ark</groupId>
    <artifactId>spring</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <version>9.0.27</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-taglibs</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

@Entity
@Table(name = "t_user")
public class User implements UserDetails {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Size(min=2, message = "Не меньше 5 знаков")
    private String username;
    @Size(min=2, message = "Не меньше 5 знаков")
    private String password;
    @Transient
    private String passwordConfirm;
    @ManyToMany(fetch = FetchType.EAGER)
    private Set<Role> roles;

    public User() {
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @Override
    public String getUsername() {
        return username;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return getRoles();
    }

    @Override
    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getPasswordConfirm() {
        return passwordConfirm;
    }

    public void setPasswordConfirm(String passwordConfirm) {
        this.passwordConfirm = passwordConfirm;
    }

    public Set<Role> getRoles() {
        return roles;
    }

    public void setRoles(Set<Role> roles) {
        this.roles = roles;
    }
}

@Entity
@Table(name = "t_role")
public class Role implements GrantedAuthority {
    @Id
    private Long id;
    private String name;
    @Transient
    @ManyToMany(mappedBy = "roles")
    private Set<User> users;
    public Role() {
    }

    public Role(Long id) {
        this.id = id;
    }

    public Role(Long id, String name) {
        this.id = id;
        this.name = name;
    }

    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 Set<User> getUsers() {
        return users;
    }

    public void setUsers(Set<User> users) {
        this.users = users;
    }

    @Override
    public String getAuthority() {
        return getName();
    }
}

@Service
public class UserService implements UserDetailsService {
    @PersistenceContext
    private EntityManager em;
    @Autowired
    UserRepository userRepository;
    @Autowired
    RoleRepository roleRepository;
    @Autowired
    BCryptPasswordEncoder bCryptPasswordEncoder;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userRepository.findByUsername(username);

        if (user == null) {
            throw new UsernameNotFoundException("User not found");
        }

        return user;
    }

    public User findUserById(Long userId) {
        Optional<User> userFromDb = userRepository.findById(userId);
        return userFromDb.orElse(new User());
    }

    public List<User> allUsers() {
        return userRepository.findAll();
    }

    public boolean saveUser(User user) {
        User userFromDB = userRepository.findByUsername(user.getUsername());

        if (userFromDB != null) {
            return false;
        }

        user.setRoles(Collections.singleton(new Role(1L, "ROLE_USER")));
        user.setPassword(bCryptPasswordEncoder.encode(user.getPassword()));
        userRepository.save(user);
        return true;
    }

    public boolean deleteUser(Long userId) {
        if (userRepository.findById(userId).isPresent()) {
            userRepository.deleteById(userId);
            return true;
        }
        return false;
    }

    public List<User> usergtList(Long idMin) {
        return em.createQuery("SELECT u FROM User u WHERE u.id > :paramId", User.class)
                .setParameter("paramId", idMin).getResultList();
    }
}

@Controller
public class RegistrationController {

    @Autowired
    private UserService userService;

    @GetMapping("/registration")
    public String registration(Model model) {
        model.addAttribute("userForm", new User());

        return "registration";
    }

    @PostMapping("/registration")
    public String addUser(@ModelAttribute("userForm") @Valid User userForm, BindingResult bindingResult, Model model) {

        if (bindingResult.hasErrors()) {
            return "registration";
        }
        if (!userForm.getPassword().equals(userForm.getPasswordConfirm())){
            model.addAttribute("passwordError", "Пароли не совпадают");
            return "registration";
        }
        if (!userService.saveUser(userForm)){
            model.addAttribute("usernameError", "Пользователь с таким именем уже существует");
            return "registration";
        }

        return "redirect:/";
    }
}

@Controller
public class AdminController {
    @Autowired
    private UserService userService;

    @GetMapping("/admin")
    public String userList(Model model) {
        model.addAttribute("allUsers", userService.allUsers());
        return "admin";
    }

    @PostMapping("/admin")
    public String  deleteUser(@RequestParam(required = true, defaultValue = "" ) Long userId,
                              @RequestParam(required = true, defaultValue = "" ) String action,
                              Model model) {
        if (action.equals("delete")){
            userService.deleteUser(userId);
        }
        return "redirect:/admin";
    }

    @GetMapping("/admin/gt/{userId}")
    public String  gtUser(@PathVariable("userId") Long userId, Model model) {
        model.addAttribute("allUsers", userService.usergtList(userId));
        return "admin";
    }
}

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
    @Autowired
    UserService userService;

    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    protected void configure(HttpSecurity httpSecurity) throws Exception {
        httpSecurity
                .csrf()
                    .disable()
                .authorizeRequests()
                    //Доступ только для не зарегистрированных пользователей
                    .antMatchers("/registration").not().fullyAuthenticated()
                    //Доступ только для пользователей с ролью Администратор
                    .antMatchers("/admin/**").hasRole("ADMIN")
                    .antMatchers("/news").hasRole("USER")
                    //Доступ разрешен всем пользователей
                    .antMatchers("/", "/resources/**").permitAll()
                //Все остальные страницы требуют аутентификации
                .anyRequest().authenticated()
                .and()
                    //Настройка для входа в систему
                    .formLogin()
                    .loginPage("/login")
                    //Перенарпавление на главную страницу после успешного входа
                    .defaultSuccessUrl("/")
                    .permitAll()
                .and()
                    .logout()
                    .permitAll()
                    .logoutSuccessUrl("/");
    }

    @Autowired
    protected void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userService).passwordEncoder(bCryptPasswordEncoder());
    }
}

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="sec" uri="http://www.springframework.org/security/tags" %>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>

<!DOCTYPE HTML>
<html>
<head>
  <title>Главная</title>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
  <link rel="stylesheet" type="text/css" href="${contextPath}/resources/css/style.css">
</head>
<body>
<div>
  <h3>${pageContext.request.userPrincipal.name}</h3>
  <sec:authorize access="!isAuthenticated()">
    <h4><a href="/login">Войти</a></h4>
    <h4><a href="/registration">Зарегистрироваться</a></h4>
  </sec:authorize>
  <sec:authorize access="isAuthenticated()">
    <h4><a href="/logout">Выйти</a></h4>
  </sec:authorize>
  <h4><a href="/news">Новости (только пользователь)</a></h4>
  <h4><a href="/admin">Пользователи (только админ)</a></h4>
</div>
</body>
</html>

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Регистрация</title>
</head>

<body>
<div>
  <form:form method="POST" modelAttribute="userForm">
    <h2>Регистрация</h2>
    <div>
      <form:input type="text" path="username" placeholder="Username"
                  autofocus="true"></form:input>
      <form:errors path="username"></form:errors>
        ${usernameError}
    </div>
    <div>
      <form:input type="password" path="password" placeholder="Password"></form:input>
    </div>
    <div>
      <form:input type="password" path="passwordConfirm"
                  placeholder="Confirm your password"></form:input>
      <form:errors path="password"></form:errors>
        ${passwordError}
    </div>
    <button type="submit">Зарегистрироваться</button>
  </form:form>
  <a href="/">Главная</a>
</div>
</body>
</html>

<%@ taglib prefix="sec" uri="http://www.springframework.org/security/tags" %>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Log in with your account</title>
</head>

<body>
<sec:authorize access="isAuthenticated()">
  <% response.sendRedirect("/"); %>
</sec:authorize>
<div>
  <form method="POST" action="/login">
    <h2>Вход в систему</h2>
    <div>
      <input name="username" type="text" placeholder="Username"
             autofocus="true"/>
      <input name="password" type="password" placeholder="Password"/>
      <button type="submit">Log In</button>
      <h4><a href="/registration">Зарегистрироваться</a></h4>
    </div>
  </form>
</div>

</body>
</html>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Log in with your account</title>
  <link rel="stylesheet" type="text/css" href="${contextPath}/resources/css/style.css">
</head>

<body>
<div>
  <table>
    <thead>
    <th>ID</th>
    <th>UserName</th>
    <th>Password</th>
    <th>Roles</th>
    </thead>
    <c:forEach items="${allUsers}" var="user">
      <tr>
        <td>${user.id}</td>
        <td>${user.username}</td>
        <td>${user.password}</td>
        <td>
          <c:forEach items="${user.roles}" var="role">${role.name}; </c:forEach>
        </td>
        <td>
          <form action="${pageContext.request.contextPath}/admin" method="post">
            <input type="hidden" name="userId" value="${user.id}"/>
            <input type="hidden" name="action" value="delete"/>
            <button type="submit">Delete</button>
          </form>
        </td>
      </tr>
    </c:forEach>
  </table>
  <a href="/">Главная</a>
</div>
</body>
</html>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Новости</title>
</head>
<body>
<div>
    <h2>Новости <br> Только для залогинившихся пользователей.</h2>
    <a href="/">Главная</a>
</div>
</body>
</html>

INSERT INTO public.t_role(id, name)
  VALUES (1, 'ROLE_USER'), (2, 'ROLE_ADMIN'); 

INSERT INTO public.t_user_roles(user_id, roles_id)
  VALUES (1, 2);