准备：

版本信息

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springsecuritydemo01</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springsecuritydemo01</name>
    <description>springsecuritydemo01</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>

jar包

<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>

控制层

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

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

第一种：通过配置文件

spring.security.user.name=test
spring.security.user.password=test

第二种：通过配置类

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {

        BCryptPasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
        String password = passwordEncoder.encode("test123");

        auth.inMemoryAuthentication().withUser("test").password(password).roles("admin");
    }

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

第三种：自定义编写实现类

第一步 创建配置类，设置使用哪个userDetailService实现类

@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();
    }
}

第二步 编写实现类，返回User对象，User对象有用户名密码和操作权限

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

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

        List<GrantedAuthority> authorityList = AuthorityUtils.commaSeparatedStringToAuthorityList("admin");

        return new User("test",new BCryptPasswordEncoder().encode("123"),authorityList);
    }
}