Spring Boot 2.7+ 浏览器请求没法匹配时404，500，自定义显示错误页面 Whitelabel Error Page This application has no explicit mapping for /error

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Fri Sep 08 11:23:31 CST 2023

There was an unexpected error (type=Not Found, status=404).

 

浏览器直接请求，没有匹配的API时

会跳转到一个错误页面，显示不好看

 

如何自定义?

 

翻源码，有一个顶层接口：

/**
 * Interface that can be implemented by beans that resolve error views.
 *
 * @author Phillip Webb
 * @since 1.4.0
 */
@FunctionalInterface
public interface ErrorViewResolver {

    /**
     * Resolve an error view for the specified details.
     * @param request the source request
     * @param status the http status of the error
     * @param model the suggested model to be used with the view
     * @return a resolved {@link ModelAndView} or {@code null}
     */
    ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status, Map<String, Object> model);

}


查看实现类

DefaultErrorViewResolver

当没有其他配置时，会走这个方法

private ModelAndView resolveResource(String viewName, Map<String, Object> model) {
    for (String location : this.resources.getStaticLocations()) {
       try {
          Resource resource = this.applicationContext.getResource(location);
          resource = resource.createRelative(viewName + ".html");
          if (resource.exists()) {
             return new ModelAndView(new HtmlResourceView(resource), model);
          }
       }
       catch (Exception ex) {
       }
    }
    return null;
}

实际会找/resources/META-INF/resources/error/ 这个目录下找有没有404.html 500/html
* 最终会编译到boot.jar: /META-INF/resources/error/

所以只要在这个目录下 加404.html 500.html即可