Nginx反向代理出现静态文件404异常处理

location ^~ /gongju/ {
    proxy_pass         http://B网站/;
    proxy_set_header   Host $host;
    proxy_set_header   X-Real-IP $remote_addr;
    proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header   X-Forwarded-Proto $scheme;

    # 修复重定向路径
    proxy_redirect ~^/(.*)$ /gongju/$1;

    sub_filter_once off;
    sub_filter_types *;

    # 1. HTML/JS/CSS 常见路径格式
    sub_filter '="/'        '="/gongju/';
    sub_filter "='/"        "='/gongju/";
    sub_filter 'url(/'      'url(/gongju/';
    sub_filter 'url("/'     'url("/gongju/';
    sub_filter "url('/"     "url('/gongju/";
    sub_filter 'src="/'     'src="/gongju/';
    sub_filter "src='/"     "src='/gongju/";
    sub_filter 'href="/'    'href=" rel="external nofollow" /gongju/';
    sub_filter "href='/"    "href='/gongju/";
    sub_filter 'action="/'  'action="/gongju/';
    sub_filter "action='/"  "action='/gongju/";

    # 2. JS中拼接路径的字符串
    sub_filter '"/api'      '"/gongju/api';
    sub_filter "'/api"      "'/gongju/api";
    sub_filter '"/static'   '"/gongju/static';
    sub_filter "'/static"   "'/gongju/static";

    # 3. 后端返回中的硬编码链接
    sub_filter 'http://B网站' '$scheme://$host/gongju';
}