public String getMcCreateTradeIp(HttpServletRequest request) {
    String mc_create_trade_ip = "/";
    if(!request.getRemoteAddr().equals("")){
        mc_create_trade_ip = request.getRemoteAddr();
    };
 return mc_create_trade_ip;      
}  
function get_mcCreateTradeIp(){
  mc_create_trade_ip = "/";
  if ($_SERVER['REMOTE_ADDR']){
    $mc_create_trade_ip = $_SERVER['REMOTE_ADDR']
      }elseif (getenv("REMOTE_ADDR")){
    $mc_create_trade_ip = getenv("REMOTE_ADDR");
  }
  return $mc_create_trade_ip;
}

#修改default.conf配置文件
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr; 
proxy_set_header X-Real-Port $remote_port; 
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

#修改httpd.conf文件
vi /usr/local/apache/conf/httpd.conf
Include conf/extra/httpd-remoteip.conf
＃ 加载mod_remoteip.so模块 
LoadModule remoteip_module modules/mod_remoteip.so 
RemoteIPHeader X-Forwarded-For 
RemoteIPInternalProxy <ip_range1><ip_range2> …… <ip_rangex>

//获取请求头中的真实IP
public String getMcCreateTradeIp(HttpServletRequest request) {
    //...其他逻辑
    String mc_create_trade_ip = "/";
    String mcProxyIp = "/";
    String mcXffIp = "/";
    if(!request.getRemoteAddr().equals("")){
        mc_create_trade_ip = request.getRemoteAddr();//根据真实情况获取
    };
    if (!request.getHeader("X-Real-IP").equals("")){
        mcProxyIp=request.getHeader("X-Real-IP");
        mc_create_trade_ip = mcProxyIp;//根据真实情况获取
    }else if(!request.getHeader("X-Forwarded-For").equals("")){
        String[] mcXffIps = request.getHeader("X-Forwarded-For").split(",");
        mc_create_trade_ip =mcXffIps[0];//根据真实情况获取
    }else{
        mc_create_trade_ip="/";
    }
    //...其他逻辑，根据真实情况获取真实IP
 return mc_create_trade_ip;      
}  

POST /test HTTP/1.1
Host: aaa.bb.cn
Cookie:  xxxx
Content-Length: 1420
Cache-Control: max-age=0
Sec-Ch-Ua: " Not A;Brand";v="99", "Chromium";v="102", "Google Chrome";v="102"
Sec-Ch-Ua-Mobile: ?0
Sec-Ch-Ua-Platform: "Windows"
Upgrade-Insecure-Requests: 1
Origin: https://aaa.bb.cn
Content-Type: application/x-www-form-urlencoded
X-Forwarded-For: 120.24.169.223,8.8.8.8
Client-IP: 120.24.169.22
X-Client-IP: 120.24.169.22
X-Originating-IP: 120.24.169.22
X-Real-IP: 120.24.169.22
X-Remote-Addr: 120.24.169.22
X-Remote-IP: 120.24.169.22
User-Agent: Mozilla/5.0 (Linux; Android 4.4.2; Nexus 4 Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.114 Mobile Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: same-site
Sec-Fetch-Mode: navigate
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8
Connection: close