Java example source code file (NetworkConfiguration.java)

This example Java source code file (NetworkConfiguration.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

collections, hashmap, inet4address, inet6address, inetaddress, ioexception, iterable, linkedlist, list, map, net, network, networkconfiguration, networkinterface, string, util, windows

The NetworkConfiguration.java Java example source code

/*
 * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.net.*;
import java.util.*;
import java.io.IOException;

/**
 * Helper class for multicasting tests.
 */

class NetworkConfiguration {

    private Map<NetworkInterface,List ip4Interfaces;
    private Map<NetworkInterface,List ip6Interfaces;

    private NetworkConfiguration(Map<NetworkInterface,List ip4Interfaces,
                                 Map<NetworkInterface,List ip6Interfaces)
    {
        this.ip4Interfaces = ip4Interfaces;
        this.ip6Interfaces = ip6Interfaces;
    }

    Iterable<NetworkInterface> ip4Interfaces() {
        return ip4Interfaces.keySet();
    }

    Iterable<NetworkInterface> ip6Interfaces() {
        return ip6Interfaces.keySet();
    }

    Iterable<InetAddress> ip4Addresses(NetworkInterface nif) {
        return ip4Interfaces.get(nif);
    }

    Iterable<InetAddress> ip6Addresses(NetworkInterface nif) {
        return ip6Interfaces.get(nif);
    }

    // IPv6 not supported for Windows XP/Server 2003
    static boolean isIPv6Supported() {
        if (System.getProperty("os.name").startsWith("Windows")) {
            String ver = System.getProperty("os.version");
            int major = Integer.parseInt(ver.split("\\.")[0]);
            return (major >= 6);
        }
        return true;
    }

    static NetworkConfiguration probe() throws IOException {
        Map<NetworkInterface,List ip4Interfaces =
            new HashMap<NetworkInterface,List();
        Map<NetworkInterface,List ip6Interfaces =
            new HashMap<NetworkInterface,List();
        boolean isIPv6Supported = isIPv6Supported();

        // find the interfaces that support IPv4 and IPv6
        List<NetworkInterface> nifs = Collections
            .list(NetworkInterface.getNetworkInterfaces());
        for (NetworkInterface nif: nifs) {
            // ignore intertaces that are down or don't support multicast
            if (!nif.isUp() || !nif.supportsMulticast() || nif.isLoopback())
                continue;

            List<InetAddress> addrs = Collections.list(nif.getInetAddresses());
            for (InetAddress addr: addrs) {
                if (!addr.isAnyLocalAddress()) {
                    if (addr instanceof Inet4Address) {
                        List<InetAddress> list = ip4Interfaces.get(nif);
                        if (list == null) {
                            list = new LinkedList<InetAddress>();
                        }
                        list.add(addr);
                        ip4Interfaces.put(nif, list);
                    } else if (isIPv6Supported && (addr instanceof Inet6Address)) {
                        List<InetAddress> list = ip6Interfaces.get(nif);
                        if (list == null) {
                            list = new LinkedList<InetAddress>();
                        }
                        list.add(addr);
                        ip6Interfaces.put(nif, list);
                    }
                }
            }
        }
        return new NetworkConfiguration(ip4Interfaces, ip6Interfaces);
    }
}