java獲取客戶端請求IP地址（公網ip）

之前寫了一個獲取ip地址的方法，但是放網上一查顯示此Ip地址是局域網ip地址，要是想獲取請求端的真實公網ip地址怎么樣了，看了一些別人的博客后發現，想要獲取客戶端的公網ip必須借助第三方。

package com.jzproject.common.util;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;

/**
 * 
 * @Description：IP工具類
 * @author zrt
 * @date 2018年9月22日 上午10:38:13
 */
public class IPUtil {
   
   private static final Logger logger = LoggerFactory.getLogger(IPUtil.class);
   
   
   
   /**
    * 
    * @Description：獲取客戶端的IP
    * @author zrt
    * @date 2018年9月22日 上午10:39:44
    */
    public static String getIpAddress(HttpServletRequest request) {
       //注意本地測試時，瀏覽器請求不要用localhost，要用本機IP訪問項目地址，不然這里取不到ip
       // 獲取請求主機IP地址,如果通過代理進來，則透過防火牆獲取真實IP地址

        String ip = request.getHeader("X-Forwarded-For");
        if (logger.isInfoEnabled()) {
            logger.info("getIpAddress(HttpServletRequest) - X-Forwarded-For - String ip=" + ip);
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
                if (logger.isInfoEnabled()) {
                    logger.info("getIpAddress(HttpServletRequest) - Proxy-Client-IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
                if (logger.isInfoEnabled()) {
                    logger.info("getIpAddress(HttpServletRequest) - WL-Proxy-Client-IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
                if (logger.isInfoEnabled()) {
                    logger.info("getIpAddress(HttpServletRequest) - HTTP_CLIENT_IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
                if (logger.isInfoEnabled()) {
                    logger.info("getIpAddress(HttpServletRequest) - HTTP_X_FORWARDED_FOR - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (logger.isInfoEnabled()) {
                    logger.info("getIpAddress(HttpServletRequest) - getRemoteAddr - String ip=" + ip);
                }
            }
        } else if (ip.length() > 15) {
            String[] ips = ip.split(",");
            for (int index = 0; index < ips.length; index++) {
                String strIp = (String) ips[index];
                if (!("unknown".equalsIgnoreCase(strIp))) {
                    ip = strIp;
                    break;
                }
            }
        }
        return ip;
    }


    public static void main(String[] args) throws Exception {

        System.err.println("公網ipppppppppppp:" + getPublicIp());


    }

    /**
     * @Description：獲取客戶端外網ip
     * @Author：zrt
     * @Date：2019/6/13 11:23
     **/
    public static String getPublicIp() {
        try {
            String path = "http://iframe.ip138.com/ic.asp";// 要獲得html頁面內容的地址

            URL url = new URL(path);// 創建url對象

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();// 打開連接

            conn.setRequestProperty("contentType", "GBK"); // 設置url中文參數編碼

            conn.setConnectTimeout(5 * 1000);// 請求的時間

            conn.setRequestMethod("GET");// 請求方式

            InputStream inStream = conn.getInputStream();
            // readLesoSysXML(inStream);

            BufferedReader in = new BufferedReader(new InputStreamReader(
                    inStream, "GBK"));
            StringBuffer buffer = new StringBuffer();
            String line = "";
            // 讀取獲取到內容的最后一行,寫入
            while ((line = in.readLine()) != null) {
                buffer.append(line);
            }
            String str = buffer.toString();
            String ipString1 = str.substring(str.indexOf("["));
            // 獲取你的IP是中間的[182.149.82.50]內容
            String ipsString2 = ipString1.substring(ipString1.indexOf("[") + 1,
                    ipString1.lastIndexOf("]"));
            //獲取當前IP地址所在地址
      /* String ipsString3=ipString1.substring(ipString1.indexOf(": "),ipString1.lastIndexOf("</center>"));
         System.err.println(ipsString3);*/

            // 返回公網IP值
            return ipsString2;

        } catch (Exception e) {
            System.out.println("獲取公網IP連接超時");
            return "連接超時";
        }
    }



}