IP Address in Java and JSF

Question

I am using the following code to get the IP address form a client.

public String getIp(@Context HttpServletRequest requestContext, @Context SecurityContext context) {
    HttpServletRequest request = (HttpServletRequest) FacesContext.getCurrentInstance().getExternalContext().getRequest();
    String ipAddress = request.getHeader("X-FORWARDED-FOR");
    if (ipAddress == null) {
        ipAddress = request.getRemoteAddr();
    }
    return ipAddress;
}

However, when it executes, it returns 0:0:0:0:0:0:0:1. It is running on my local pc, and I would expect it to return good ol 127.0.0.1. Any ideas why not?

possible duplicate of [Getting IP address of client](http://stackoverflow.com/questions/16558869/getting-ip-address-of-client) — Mitesh Pathak, Dec 19 '13 at 16:50
Not a duplicate. The question is not about getting the IP address, but about why it is 0:0:0:0:0:0:0:1 instead of 127.0.0.1 — Javier, Dec 19 '13 at 17:20
`0:0:0:0:0:0:0:1` is an IPv6 IP address. You need to ensure you set it to IPv4 if you want only the IPv4 response. See @Javier's answer. — brandonscript, Dec 19 '13 at 18:01

score 1 · Answer 1 · edited May 23 '17 at 12:31

1

However, when it executes, it returns 0:0:0:0:0:0:0:1. It is running on my local pc, and I >would expect it to return good ol 127.0.0.1. Any ideas why not?

If the machine is behind a proxy you won't be able to get it's local IP or domain information, in any server side technology

Refer [1] Getting IP address of client

edited May 23 '17 at 12:31

Community

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answered Dec 19 '13 at 16:49

Mitesh Pathak

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score 1 · Answer 2 · answered Dec 19 '13 at 17:18

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Your machine has dual stack (IPv4/IPv6). The 0:0:0:0:0:0:0:1 address (also written as ::1) is the IPv6 equivalent for localhost.

answered Dec 19 '13 at 17:18

Javier

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Best to provide the details how to set it to capture only IPv4 info ;) – brandonscript Dec 19 '13 at 18:01
The server should be bound to an IPv4 address, otherwise it listen on every address, and IPv6 is given preference. – Javier Dec 19 '13 at 19:21
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Right, but you can choose to bind only to the ipv4 interface. – brandonscript Dec 19 '13 at 19:26

score 1 · Answer 3 · edited Apr 14 '16 at 03:45

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This is late but for those who will visit this page in the future. If you are running Tomcat, you may set JAVA_OPTS environment variable and add

-Djava.net.preferIPv4Stack=true

and

-Djava.net.preferIPv4Addresses=true

In eclipse it maybe added in:

Debug As -> Debug configuration -> Environment.

edited Apr 14 '16 at 03:45

T D Nguyen

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answered Apr 14 '16 at 03:34

Carlos H. Raymundo

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IP Address in Java and JSF

3 Answers3