获取客户端真实IP地址

Java-Web获取客户端真实IP：

　　

发生的场景：服务器端接收客户端请求的时候，一般需要进行签名验证，客户端IP限定等情况，在进行客户端IP限定的时候，需要首先获取该真实的IP。

一般分为两种情况：

　　方式一、客户端未经过代理，直接访问服务器端(nginx,squid,haproxy)；

　　方式二、客户端通过多级代理，最终到达服务器端(nginx,squid,haproxy)；

客户端请求信息都包含在HttpServletRequest中，可以通过方法getRemoteAddr()获得该客户端IP。

　　方式一形式，可以直接获得该客户端真实IP。

　　方式二中通过代理的形式，此时经过多级反向的代理，通过方法getRemoteAddr()得不到客户端真实IP，可以通过x-forwarded-for获得转发后请求信息。当客户端请求被转发，IP将会追加在其后并以逗号隔开，例如：10.47.103.13,4.2.2.2,10.96.112.230。

请求中的参数：

　　request.getHeader("x-forwarded-for") : 10.47.103.13,4.2.2.2,10.96.112.230

　　request.getHeader("X-Real-IP") : 10.47.103.13

　　request.getRemoteAddr():10.96.112.230

客户端访问经过转发，IP将会追加在其后并以逗号隔开。最终准确的客户端信息为：

• x-forwarded-for 不为空，则为逗号前第一个IP ；
• X-Real-IP不为空，则为该IP ；
• 否则为getRemoteAddr() ；

相关请求头的解释：

• X-Forwarded-For ：这是一个 Squid 开发的字段，只有在通过了HTTP代理或者负载均衡服务器时才会添加该项。　　　　

　　　　格式为X-Forwarded-For:client1,proxy1,proxy2，一般情况下，第一个ip为客户端真实ip，后面的为经过的代理服务器ip。现在大部分的代理都会加上这个请求头。

• Proxy-Client-IP/WL- Proxy-Client-IP ：这个一般是经过apache http服务器的请求才会有，用apache http做代理时一般会加上Proxy-Client-IP请求头，而WL-Proxy-Client-IP是他的weblogic插件加上的头。
• HTTP_CLIENT_IP ：有些代理服务器会加上此请求头。
• X-Real-IP  ：nginx代理一般会加上此请求头。

     /**
      * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
      * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
      */
     private String getIpAddr(HttpServletRequest request) {
         String ip = request.getHeader("x-forwarded-for");
         System.out.println("x-forwarded-for ip: " + ip);
         if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
             // 多次反向代理后会有多个ip值，第一个ip才是真实ip
             if( ip.indexOf(",")!=-1 ){
                 ip = ip.split(",")[0];
             }
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("Proxy-Client-IP");
             System.out.println("Proxy-Client-IP ip: " + ip);
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("WL-Proxy-Client-IP");
             System.out.println("WL-Proxy-Client-IP ip: " + ip);
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("HTTP_CLIENT_IP");
             System.out.println("HTTP_CLIENT_IP ip: " + ip);
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("HTTP_X_FORWARDED_FOR");
             System.out.println("HTTP_X_FORWARDED_FOR ip: " + ip);
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("X-Real-IP");
             System.out.println("X-Real-IP ip: " + ip);
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getRemoteAddr();
             System.out.println("getRemoteAddr ip: " + ip);
         }
         System.out.println("获取客户端ip: " + ip);
         return ip;
     }

 import javax.servlet.http.HttpServletRequest;

 /**
 * IP校验
 */
 public class IPUtils {

     public static String getClientAddress(HttpServletRequest request) {
         if (request == null) {
             return "unknown";
         }
         String ip = request.getHeader("x-forwarded-for");
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("Proxy-Client-IP");
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("X-Forwarded-For");
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("WL-Proxy-Client-IP");
         }
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getHeader("X-Real-IP");
         }

         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
             ip = request.getRemoteAddr();
         }
         return ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;
     }

 }

 public String getIpAddr(HttpServletRequest request){
         String 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") || ipAddress.equals("0:0:0:0:0:0:0:1")){
                     //根据网卡取本机配置的IP
                     InetAddress inet=null;
                     try {
                         inet = InetAddress.getLocalHost();
                     } catch (UnknownHostException e) {
                         e.printStackTrace();
                     }
                     ipAddress= inet.getHostAddress();
                 }
             }
             //对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
             if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15
                 if(ipAddress.indexOf(",")>0){
                     ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
                 }
             }
             return ipAddress;
     }

太平洋网络IP地址查询Web接口：http://whois.pconline.com.cn/

 import java.io.BufferedReader;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.net.HttpURLConnection;
 import java.net.URL;

 /**
  *     根据IP地址获取详细的地域信息 第一个方法是传入ip获取真实地址 最后一个方法是获取访问者真实ip 即使通过Nginx多层代理也可以获取
  */
 public class AddressUtils {

     public static String getAddresses(String content, String encodingString) throws UnsupportedEncodingException {
         // 这里调用pconline的接口
         String urlStr = "http://ip.taobao.com/service/getIpInfo.php";
         // 从http://whois.pconline.com.cn取得IP所在的省市区信息
         String returnStr = getResult(urlStr, content, encodingString);
         if (returnStr != null) {
             // 处理返回的省市区信息
             System.out.println(returnStr);
             String[] temp = returnStr.split(",");
             if (temp.length < 3) {
                 return "0";// 无效IP，局域网测试
             }
             String country = "";
             String area = "";
             String region = "";
             String city = "";
             String county = "";
             String isp = "";
             for (int i = 0; i < temp.length; i++) {
                 switch (i) {
                 case 1:
                     country = (temp[i].split(":"))[2].replaceAll("\"", "");
                     country = decodeUnicode(country);// 国家
                     break;
 //                  case 3:
 //                      area = (temp[i].split(":"))[1].replaceAll("\"", "");
 //                      area =decodeUnicode(area);//地区
 //                   break;
                 case 5:
                     region = (temp[i].split(":"))[1].replaceAll("\"", "");
                     region = decodeUnicode(region);// 省份
                     break;
                 case 7:
                     city = (temp[i].split(":"))[1].replaceAll("\"", "");
                     city = decodeUnicode(city);// 市区
                     break;
                 case 9:
                     county = (temp[i].split(":"))[1].replaceAll("\"", "");
                     county = decodeUnicode(county);// 地区
                     break;
                 case 11:
                     isp = (temp[i].split(":"))[1].replaceAll("\"", "");
                     isp = decodeUnicode(isp);// ISP公司
                     break;
                 }
             }
             System.out.println(country + area + "=" + region + "=" + city + "=" + county + "=" + isp);
             StringBuffer sb = new StringBuffer(country).append(region).append(city).append(county).append(" ")
                     .append(isp);
             return sb.toString();
         }
         return null;
     }

     /**
      * @param urlStr   请求的地址
      * @param content  请求的参数 格式为：name=xxx&pwd=xxx
      * @param encoding 服务器端请求编码。如GBK,UTF-8等
      * @return
      */
     private static String getResult(String urlStr, String content, String encoding) {
         URL url = null;
         HttpURLConnection connection = null;
         try {
             url = new URL(urlStr);
             connection = (HttpURLConnection) url.openConnection();// 新建连接实例
             connection.setConnectTimeout(3000);// 设置连接超时时间，单位毫秒
             connection.setReadTimeout(3000);// 设置读取数据超时时间，单位毫秒
             connection.setDoOutput(true);// 是否打开输出流 true|false
             connection.setDoInput(true);// 是否打开输入流true|false
             connection.setRequestMethod("POST");// 提交方法POST|GET
             connection.setUseCaches(false);// 是否缓存true|false
             connection.connect();// 打开连接端口
             DataOutputStream out = new DataOutputStream(connection.getOutputStream());// 打开输出流往对端服务器写数据
             out.writeBytes(content);// 写数据(提交表单)
             out.flush();// 刷新
             out.close();// 关闭输出流
             // 往对端写完数据对端服务器返回数据,以BufferedReader流来读取
             BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), encoding));
             StringBuffer buffer = new StringBuffer();
             String line = "";
             while ((line = reader.readLine()) != null) {
                 buffer.append(line);
             }
             reader.close();
             return buffer.toString();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             if (connection != null) {
                 connection.disconnect();// 关闭连接
             }
         }
         return null;
     }

     /**
      * unicode 转换成 中文
      */
     public static String decodeUnicode(String theString) {
         char aChar;
         int len = theString.length();
         StringBuffer outBuffer = new StringBuffer(len);
         for (int x = 0; x < len;) {
             aChar = theString.charAt(x++);
             if (aChar == '\\') {
                 aChar = theString.charAt(x++);
                 if (aChar == 'u') {
                     int value = 0;
                     for (int i = 0; i < 4; i++) {
                         aChar = theString.charAt(x++);
                         switch (aChar) {
                         case '0':
                         case '1':
                         case '2':
                         case '3':
                         case '4':
                         case '5':
                         case '6':
                         case '7':
                         case '8':
                         case '9':
                             value = (value << 4) + aChar - '0';
                             break;
                         case 'a':
                         case 'b':
                         case 'c':
                         case 'd':
                         case 'e':
                         case 'f':
                             value = (value << 4) + 10 + aChar - 'a';
                             break;
                         case 'A':
                         case 'B':
                         case 'C':
                         case 'D':
                         case 'E':
                         case 'F':
                             value = (value << 4) + 10 + aChar - 'A';
                             break;
                         default:
                             throw new IllegalArgumentException("Malformed      encoding.");
                         }
                     }
                     outBuffer.append((char) value);
                 } else {
                     if (aChar == 't') {
                         aChar = '\t';
                     } else if (aChar == 'r') {
                         aChar = '\r';
                     } else if (aChar == 'n') {
                         aChar = '\n';
                     } else if (aChar == 'f') {
                         aChar = '\f';
                     }
                     outBuffer.append(aChar);
                 }
             } else {
                 outBuffer.append(aChar);
             }
         }
         return outBuffer.toString();
     }

     // 测试
     public static void main(String[] args) {
         AddressUtils addressUtils = new AddressUtils();

         /**
          *     测试IP：111.121.72.101  中国贵州省贵阳市 电信
          */
         String ip = "111.121.72.101";
         String address = "";
         try {
             address = addressUtils.getAddresses("ip=" + ip, "utf-8");
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
         }
         System.out.println(address);//中国贵州省贵阳市 电信
     }
 }