SpringBoot 错误页面跳转方式

package com.study.demo.config;
import org.springframework.boot.WEB.server.ErrorPage;
import org.springframework.boot.web.server.ErrorPageReGIStrar;
import org.springframework.boot.web.server.ErrorPageRegistry;
import org.springframework.Http.httpstatus;
import org.springframework.stereotype.Component;

@Component
public class ErrorPageConfig implements ErrorPageRegistrar {
    @Override
    public void registerErrorPages(ErrorPageRegistry registry) {
        ErrorPage error400Page = new ErrorPage(HttpStatus.BAD_REQUEST, "/errorPageController/error_400");
        ErrorPage error401Page = new ErrorPage(HttpStatus.UNAUTHORIZED, "/errorPageController/error_401");
        ErrorPage error404Page = new ErrorPage(HttpStatus.NOT_FOUND, "/errorPageController/error_404");
        ErrorPage error500Page = new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/errorPageController/error_500");
        registry.addErrorPages(error400Page,error401Page,error404Page,error500Page);
    }
}

package com.study.demo.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping("/errorPageController")
public class ErrorPageController {
    @RequestMapping("/error_{errorCode}")
    public String error(@PathVariable int errorCode){
        String responseMsg;
        switch (errorCode) {
            case 400: responseMsg = "/400.html"; break;
            case 401: responseMsg = "/401.html"; break;
            case 404: responseMsg = "/404.html"; break;
            case 500: responseMsg = "/500.html"; break;
            default: responseMsg = "/404.html"; break;
        }
        return responseMsg;
    }
}

private static final String[] CLASSPATH_RESOURCE_LOCATIONS = new String[]{
"classpath:/META-INF/resources/",
 "classpath:/resources/", 
 "classpath:/static/", 
 "classpath:/public/"
 };
 // 注：还有一个默认的根路径    "/"

//在DefaultErrorViewResolver中有一段代码
// 处理4xx和5xx的请求
static {
    Map<Series, String> views = new EnumMap(Series.class);
    views.put(Series.CLIENT_ERROR, "4xx");
    views.put(Series.SERVER_ERROR, "5xx");
    SERIES_VIEWS = Collections.unmodifiableMap(views);
}
// 解析，并会跳转到error/错误状态码； 页面中
private ModelAndView resolve(String viewName, Map<String, Object> model) {
    String errorViewName = "error/" + viewName;
    TemplateAvailabilityProvider provider = this.templateAvailabilityProviders.getProvider(errorViewName, this.applicationContext);
    // 对是否有模板引擎做出相应的视图处理
    return provider != null ? new ModelAndView(errorViewName, model) : this.resolveResource(errorViewName, model);
}