配置错误页面

@Controller
@RequestMapping(value = "/demo")
public class ViewController
		@GetMapping("/404")
		public String to404(Model model) {
		    return "404";
		}
		
		@GetMapping("/500/{msg}")
		public String to500(Model model, @PathVariable(value = "msg", required = false) String msg) {
		    model.addAttribute("msg", msg);
		    return "500";
		}
}

@Configuration
public class ErrorPageConfig implements ErrorPageRegistrar {

    @Override
    public void registerErrorPages(ErrorPageRegistry registry) {
        ErrorPage[] errorPages = new ErrorPage[2];
        errorPages[0] = new ErrorPage(HttpStatus.NOT_FOUND, "/demo/404");
        errorPages[1] = new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/demo/500");
        registry.addErrorPages(errorPages);
    }
}