SpringBoot隐藏真实地址

@Configuration
public class MyConfig implements WebMvcConfigurer {
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
        registry.addViewController("/index.html").setViewName("index");        registry.addViewController("/main.html").setViewName("dashboard");
    }
}

@Controller
public class IndexController {
    @RequestMapping("/userin")
    private String UserIn(Model model, @RequestParam("username") String username , @RequestParam("password") String password, HttpSession  session){
        session.setAttribute("name",username);
        if(StringUtils.hasLength(username) && password.equals("123")){
           return "redirect:/main.html";//重定向进入
        }else {
            model.addAttribute("msg","用户名或密码错误");
            return "index";
        }
    }
}