How can I retrieve IP address from HTTP header in Java [duplicate]

Use the getHeader(String Name) method of the javax.servlet.http.HttpServletRequest object to retrieve the value of Remote_Addr variable. Here is the sample code:

String ipAddress = request.getHeader("Remote_Addr");

If this code returns empty string, then use this way:

String ipAddress = request.getHeader("HTTP_X_FORWARDED_FOR");

if (ipAddress == null) {
    ipAddress = request.getRemoteAddr();
}