Java IP Address Get getFirstNonLoopbackAddress(boolean preferIpv4, boolean preferIPv6)

Description

Get the first non-loopback address.

License

Apache License

Parameter

Parameter	Description
preferIpv4	If you want the Internet Protocol version 4 (IPv4) address, this value must be true .
preferIPv6	If you want the Internet Protocol version 6 (IPv6) address, this value must be true . If the preferIpv4 is set to true , this value is ignored

Exception

Parameter	Description
SocketException	If an I/O error occurs.

Return

The first non loopback address or null if there are no non-loopback addresses.

Declaration

public static InetAddress getFirstNonLoopbackAddress(boolean preferIpv4, boolean preferIPv6)
        throws SocketException 

Method Source Code

//package com.java2s;
/*//from   ww  w.  java 2  s  .  co  m
 * Copyright to the original author or authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.net.*;
import java.util.Enumeration;

public class Main {
    /**
     * Get the first non-loopback address.
     *
     * @param preferIpv4 If you want the Internet Protocol version 4 (IPv4) address, this value must be {@code true}.
     * @param preferIPv6 If you want the  Internet Protocol version 6 (IPv6) address, this value must be {@code true}.
     *                   If the {@code preferIpv4} is set to {@code true}, this value is ignored
     * @return The first non loopback address or {@code null} if there are no non-loopback addresses.
     * @throws SocketException If an I/O error occurs.
     */
    public static InetAddress getFirstNonLoopbackAddress(boolean preferIpv4, boolean preferIPv6)
            throws SocketException {
        Enumeration en = NetworkInterface.getNetworkInterfaces();
        while (en.hasMoreElements()) {
            NetworkInterface i = (NetworkInterface) en.nextElement();
            for (Enumeration en2 = i.getInetAddresses(); en2.hasMoreElements();) {
                InetAddress addr = (InetAddress) en2.nextElement();
                if (!addr.isLoopbackAddress()) {
                    if (addr instanceof Inet4Address) {
                        if (preferIPv6) {
                            continue;
                        }
                        if (preferIpv4)
                            return addr;
                    }
                    if (addr instanceof Inet6Address) {
                        if (preferIpv4) {
                            continue;
                        }
                        if (preferIPv6)
                            return addr;
                    } else
                        return addr;
                }
            }
        }
        return null;
    }
}

Related

1. getExternalIP(String host, String regexPattern)
2. getExternalIPAddress()
3. getExternalIPAddress()
4. getExternalIPAddress()
5. getFirstLocalNonLoopbackIpAddress()
6. getFirstNonLoopBackAddress(boolean preferIpv4, boolean preferIPv6)
7. getHostIp()
8. getHostIp()
9. getHostIP()