Java Get Client IP Address

Posted By : Anil Kumar | 18-Dec-2017

Introduction:

In server side programming for security reasons we are required to get the client IP address and location details.

IP address play a key roles in getting the client/user account activity.

For getting the Client IP address we have some methods in servlet request.

In the below example we used X-Forwarded-For to get client IP address.

Example:


package com.belfrics.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.belfrics.controller.AdminController;

import java.net.HttpURLConnection;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

@Component
public class IPConfig {

	private static HttpServletRequest request;
	private static Logger LOGGER = LoggerFactory.getLogger(AdminController.class);
	public GeoLocation result = null;

	@Autowired
	static GeoIPv4 geoIPv4;

	@Autowired
	public void setRequest(HttpServletRequest request) {
		this.request = request;
	}

	public static String getIpAddr() { 
		String ip = "";
		try (java.util.Scanner s = new java.util.Scanner(new java.net.URL("http://eth0.me/").openStream(), "UTF-8")
			.useDelimiter("\\A")) {
		    ip = s.next();
		} catch (java.io.IOException e) {
		    e.printStackTrace();
		}
		return ip;
			
	}
	public GeoLocation getClientIp() {
		String remoteAddr = "";
		String add = "";
		try{
			
			if (request != null) {
				remoteAddr = request.getHeader("X-Forwarded-For");
				if (remoteAddr == null || "".equals(remoteAddr)) {
					remoteAddr = request.getRemoteAddr();
					add = request.getRemoteHost();
					LOGGER.info("IP local details"+ request.getRemoteAddr());
					remoteAddr = request.getRemoteAddr()
					if (remoteAddr.equalsIgnoreCase("0:0:0:0:0:0:0:1")) {
					    InetAddress inetAddress = InetAddress.getLocalHost();
					    String ipAddress = inetAddress.getHostAddress();
					    remoteAddr = ipAddress;
					}
				}
			}
			
			LOGGER.info("IP address is" + remoteAddr);
			result = remoteAddr;
			
			return result;
		} catch(Exception e){
			LOGGER.info(e.getMessage());
			return null;
		}
	}

	public static GeoLocation getLocation(String ipAddress) {
		try{
			Location result = lookUp.getLocation(ipAddress);
			LOGGER.info("GeoIP getLocation: " + result);
			if (result == null) {
				return null;
			}
			return GeoLocation.map(result);
		}catch(Exception e){
			LOGGER.info(e.getMessage());
			return null;
		}
	}
}

In this example if client ip address is fetched successfully it returns the IP address and if throw any exception

returns null value

This method now can be used in whole application by calling with the class name.

When a user login in the application we get their ip address and saved the details in database.

In the application we have created to many checks for recognize and block unsucipous activity from this account and on each and every login and logout of client send him the email with their ip details.