准备：

sql数据

CREATE TABLE `users` (
  `id` int NOT NULL,
  `username` varchar(10) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `password` varchar(10) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;

INSERT INTO `users` VALUES (1, 'lucy', '123');
INSERT INTO `users` VALUES (2, 'tom', '456');

pom文件

<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>
<!--        mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>
<!--        mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
<!--        lombok简化实体类-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

properties配置文件

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root

实体类

@Data
public class Users {

    private Integer id;
    private String username;
    private String password;

}

mapper扫描

@SpringBootApplication
@MapperScan("com.example.springsecuritydemo01.mapper")
public class Springsecuritydemo01Application {

    public static void main(String[] args) {
        SpringApplication.run(Springsecuritydemo01Application.class, args);
    }

}

UsersMapper

添加@Repository注解防止@Autowired注入时飘红，可不加

@Repository
public interface UsersMapper extends BaseMapper<Users> {

}

配置类

@Configuration
public class SecurityConfigDiy extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserDetailsService userDetailsService;

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception{
        auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
    }

    @Bean
    PasswordEncoder passwordEncoder(){
        return new BCryptPasswordEncoder();
    }
}

测试Controller

@RestController
@RequestMapping("/test")
public class TestController {

    @GetMapping("/hello")
    public String hello(){
        return "hello security";
    }
}

MyUserDetailService

@Service("userDetailsService")
public class MyUserDetailService implements UserDetailsService {

    @Autowired
    private UsersMapper usersMapper;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {

        QueryWrapper<Users> wrapper = new QueryWrapper<>();
        wrapper.eq("username",username);
        Users users = usersMapper.selectOne(wrapper);
        if(users == null){
            throw new UsernameNotFoundException("用户名不存在!");
        }
        List<GrantedAuthority> authorityList = AuthorityUtils.commaSeparatedStringToAuthorityList("admin");

        return new User(users.getUsername(),new BCryptPasswordEncoder().encode(users.getPassword()),authorityList);
    }
}