ajax提交数据很多的时候报错，web后端没有接收到数据，解决方案：

tomcat

经查为tomcat默认限制post提交2M数据。这里需要修改tomcat中大配置文件server.xml文件：可以设置tomcat，server.xml中Connector中的属性，maxPostSize的值。

<Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443"
               maxPostSize="-1" 
               maxHttpHeaderSize ="102400" 
               URIEncoding="UTF-8" 
 />

红色为添加的。经查为tomcat默认限制post提交2M数据。  

nginx

如果使用了nginx，需要修改

server {
    listen 80;
    server_name www.ddrsg.com$request_uri;
    #location / {
    #add_header ‘Access-Control-Allow-Origin‘ $http_origin;
    #add_header ‘Access-Control-Allow-Credentials‘ ‘true‘;
    #add_header ‘Access-Control-Allow-Methods‘ ‘GET, POST, OPTIONS‘;
    #add_header ‘Access-Control-Allow-Headers‘ ‘DNT,web-token,app-token,Authorization,Accept,Origin,Keep-Alive,User-Agent,X-Mx-ReqToken,X-Data-Type,X-Auth-Token,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range‘;
    #add_header ‘Access-Control-Expose-Headers‘ ‘Content-Length,Content-Range‘;
    #if ($request_method = ‘OPTIONS‘) {
    #add_header ‘Access-Control-Max-Age‘ 1728000;
    #add_header ‘Content-Type‘ ‘text/plain; charset=utf-8‘;
    #add_header ‘Content-Length‘ 0;
    #return 204;
    #}
    
  #当http 的URI太长或者request header过大时会报414 Request URI too large或400 bad request错误。
   client_header_buffer_size 512k;
   large_client_header_buffers 4 512k;

    #proxy_pass http://localhost:8081;
    ##proxy_set_header Host $host;
    ##proxy_set_header X-Real-IP $remote_addr;
    ##proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    #
}

链接: https://www.fly63.com/article/detial/2298