Nginx前后端分离跨域的问题（springboot+html+js）

Nginx配置文件 夕阳骑士：https://www.jianshu.com/p/c872ffa500af

　listen 3333;
　server_name localhost;

location / {
　　　　　　　#将静态资源复制到Nginx的html下
            root   html;
            index  index.html index.htm;
            client_max_body_size 20m;
        }

        location /apis {
            if ($request_method = 'OPTIONS') {
                add_header 'Access-Control-Allow-Origin' '*';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS';
                #
                # Custom headers and headers various browsers *should* be OK with but aren't
                #
                add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
                #
                # Tell client that this pre-flight info is valid for 20 days
                #
                add_header 'Access-Control-Max-Age' 1728000;
                add_header 'Content-Type' 'text/plain charset=UTF-8';
                add_header 'Content-Length' 0;
                return 204;
            }


            if ($request_method = 'POST') {
                add_header 'Access-Control-Allow-Origin' *;
                add_header 'Access-Control-Allow-Credentials' 'true';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
            }


            if ($request_method = 'GET') {
                add_header 'Access-Control-Allow-Origin' *;
                add_header 'Access-Control-Allow-Credentials' 'true';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
            }
            # 匹配apis之后的路径和参数
            rewrite  ^.+apis/?(.*)$ /$1 break;
            include  uwsgi_params;
            # 实际调用的API，springboot启动的链接
            proxy_pass http://localhost:8080;
        }

 注意一个非常重要的问题：

此时代理已经成功，后端的原来的路径也就是http://localhost:8080依然开放，所以在静态文件，也就是ajax请求后端的路径时，应该配置为新配置的路径下，例如这个配置文件为http://localhost:3333/apis/xxxxxxx;

否则即使通过写死或者注解方式解决跨域，也会存在 session 只能存入浏览器 ，后台读取不到的情况等等。