java獲取ip，spring boot獲取訪問者ip地址繞過代理

分享一個spring boot獲取訪客IP地址的類，可以繞過代理的情況，獲取到第一個客戶端的真實IP。

如果訪問過程中出現多重代理，會將所有代理的IP都返回回來，通過逗號分割，分割的字符串中第一個IP是第一個客戶端的IP。

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class Ip {

    public static String getIpAddr(HttpServletRequest request) {
        String ipAddress = null;
        try {
            ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if (ipAddress.equals("127.0.0.1")) {
                    // 根據網卡取本機配置的IP
                    InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress = inet.getHostAddress();
                }
            }
            // 對於通過多個代理的情況，第一個IP為客戶端真實IP,多個IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length()
                // = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress="";
        }
        // ipAddress = this.getRequest().getRemoteAddr();

        return ipAddress;
    }
}