详解Spring Security怎么从数据库加载我们的用户

public interface UserDetailsService {
   UserDetails loadUserByUsername(String username) throws UsernameNotFoundException;
}

public class MybatisUserDetailsService implements UserDetailsService, UserDetailsPasswordService {
	@Resource
	private UsersMapper usersMapper;
	@Override
	public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
		Users users = usersMapper.loadUserByUsername(username);
		if (null == users) {
			throw new UsernameNotFoundException(username);
		}
		return users;
	}
	@Override
	public UserDetails updatePassword(UserDetails user, String newPassword) {
		if (user instanceof Users users) {
			users.setPassword(newPassword);
			usersMapper.updateByPrimaryKeySelective(users);
		}
		return user;
	}
}

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Users implements Serializable, UserDetails {
    private Long id;
    private String username;
    private String password;
    private Boolean enabled;
    private Boolean accountnonexpired;
    private Boolean accountnonlocked;
    private Boolean credentialsnonexpired;
    private List<Roles> rolesList;
    private static final long serialVersionUID = 1L;
    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        ArrayList<SimpleGrantedAuthority> authorities = new ArrayList<>();
        for (Roles roles : getRolesList()) {
            authorities.add(new SimpleGrantedAuthority(roles.getRole()));
        }
        return authorities;
    }
    @Override
    public boolean isAccountNonExpired() {
        return accountnonexpired;
    }
    @Override
    public boolean isAccountNonLocked() {
        return accountnonlocked;
    }
    @Override
    public boolean isCredentialsNonExpired() {
        return credentialsnonexpired;
    }
    @Override
    public boolean isEnabled() {
        return enabled;
    }
}

@Bean
public UserDetailsService userDetailsService() {
   return new MybatisUserDetailsService();
}

@Bean
public SecurityFilterChain securityFilterChain(HttpSecurity httpSecurity) throws Exception {
   return httpSecurity.authorizeHttpRequests()
         .anyRequest().authenticated()
         .and()
         .formLogin()
         .defaultSuccessUrl("/hello", true) // 认证成功后访问
         .permitAll() // 白名单
         .and()
         .logout()
         .logoutUrl("/logout")
         .logoutSuccessUrl("/login") // 注销成功后访问
         .clearAuthentication(true)
         .invalidateHttpSession(true)
         .and()
         .build();
}

@GetMapping("hello")
public HashMap<String, Object> hello(Authentication authentication) {
   HashMap<String, Object> map = new HashMap<>();
   Object principal = authentication.getPrincipal();
   String name = authentication.getName();
   map.put("principal", principal);
   map.put("name", name);
   return map;
}

create table users(username varchar_ignorecase(50) not null primary key,password varchar_ignorecase(500) not null,enabled boolean not null);
create table authorities (username varchar_ignorecase(50) not null,authority varchar_ignorecase(50) not null,constraint fk_authorities_users foreign key(username) references users(username));
create unique index ix_auth_username on authorities (username,authority);

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for authorities
-- ----------------------------
DROP TABLE IF EXISTS `authorities`;
CREATE TABLE `authorities`  (
  `username` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
  `authority` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
  UNIQUE INDEX `ix_auth_username`(`username` ASC, `authority` ASC) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users`  (
  `id` bigint NOT NULL AUTO_INCREMENT,
  `username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
  `password` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
  `enabled` bit(1) NULL DEFAULT NULL,
  `accountNonExpired` bit(1) NULL DEFAULT b'1',
  `accountNonLocked` bit(1) NULL DEFAULT b'1',
  `credentialsNonExpired` bit(1) NULL DEFAULT b'1',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;

public class Users implements Serializable, UserDetails, CredentialsContainer {
	@Override
	public void eraseCredentials() {
        // 设置 password 为 null
		this.password = null;
	}
}