3.3.2 用户服务类

SpringSecurity提供了UserDetailsService，根据用户服务类，完善SpringSecurity服务，来使得原生内容嵌入到框架之中。
UserDetailsService接口如下：

public interface UserDetailsService {
    UserDetails loadUserByUsername(String var1) throws UsernameNotFoundException;
}

使用方法如下：

@Service
public class UserDetailService implements UserDetailsService {
    @Autowired
    private IUserService userService;
    @Override
    public UserDetails loadUserByUsername(String s) throws UsernameNotFoundException {
        return new UserDetail(userService.findUserByUserName(s));
    }
}