实现过程

• 把下面的配置保存成一个文件，例如：nginx_cors，引入到Nginx的代理配置中去。

if ($request_method = 'OPTIONS') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';    add_header 'Access-Control-Max-Age' 1728000;    add_header 'Content-Type' 'text/plain charset=UTF-8';    add_header 'Content-Length' 0;    return 204;}if ($request_method = 'GET') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';}if ($request_method = 'POST') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';}if ($request_method = 'PUT') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';}if ($request_method = 'PATCH') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';}if ($request_method = 'DELETE') {    add_header 'Access-Control-Allow-Origin' '*';    add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS';    add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';}

location ~* ^/ {               proxy_pass  http://www.jd.com;               access_log   /var/log/nginx/jd-access.log main;               include  /etc/nginx/nginx_cors;               max_ranges 0;           }

• 再通过访问Nginx这台机器上的地址，就能跨域访问www.jd.com下所有非权限控制的资源和数据了。