Laravel form validation fails. How to prevent the original form data from being cleared?

<code>$messages = [
            'art_editor.required' => '作者不能为空!',
            'art_title.required' => '文章标题不能为空!',
            'art_tag.required' => '文章关键字不能为空!',
            'art_thumb.required' => '请上传首页图或者添加CDN地址',
            'art_description.required' => '文章描述不能为空!',
            'art_content.required' => '请填写文章正文!',
        ];

$result = $this->validate($request, [
            'art_editor' => 'required',
            'art_title' => 'bail|required|max:25',
            'art_tag' => 'required|max:8',
            'art_thumb' => 'required',
            'art_description' => 'required|max:100',
            'art_content' => 'required'
], $messages);</code>