Returns true if the given address represents the local host. - Java Network

Java examples for Network:Network Address

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Description

Returns true if the given address represents the local host.

Demo Code

/*/*from  w ww.  j a va2s  .  c o  m*/
 *           GNU GENERAL PUBLIC LICENSE
 *              Version 2, June 1991
 *            
 * 
 *          ADDITIONAL REQUIREMENT
 *          
 * 1. If PeerfactSim.KOM is used for the evaluation in research publications, 
 * the following should be referenced: 
 * 
 * @techreport{   PWLS07,
 *    author = {Konstantin Pussep and Matthias Weinert and Nicolas Liebau and Ralf Steinmetz},
 *    title = {Flexible Framework for NAT Traversal in Peer-to-Peer Applications},
 *    month = {Nov},
 *    year = {2007},
 *    institution = {KOM - Multimedia Communications Lab, Technische Universit{\"a}t Darmstadt},
 *    address = {Merckstra{\ss}e 25, 64283 Darmstadt, Germany},
 *    number = {KOM-TR-2007-06},
 * }
 */
//package com.java2s;
import java.net.InetAddress;

import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;

public class Main {
    /**
     * Returns true if the given address represents the local host.
     * @param addr address
     * @return true if the given address represents the local host
     */
    public static boolean isLocalAddress(InetAddress addr) {
        // has local scope?
        if (hasLocalScope(addr))
            return true;

        // compare to local addresses
        Collection<NetworkInterface> nis = getNetworkInterfaces();
        for (NetworkInterface ni : nis) {
            Enumeration<InetAddress> addresses = ni.getInetAddresses();
            while (addresses.hasMoreElements()) {
                if (addresses.nextElement().equals(addr))
                    return true;
            }
        }

        // found no equal address => its not local
        return false;
    }

    /**
     * Returns true when the given address is a local address.
     * @param addr address
     * @return true when the given address is a local address
     */
    public static boolean hasLocalScope(InetAddress addr) {
        if (addr == null)
            throw new IllegalArgumentException("Must not be null!");
        return (addr.isAnyLocalAddress() || addr.isLinkLocalAddress() || addr
                .isLoopbackAddress());
    }

    /**
     * Returns all network interfaces of this host.
     * @return all network interfaces of this host
     */
    public static Collection<NetworkInterface> getNetworkInterfaces() {
        // get network interfaces
        ArrayList<NetworkInterface> result = new ArrayList<NetworkInterface>();
        Enumeration<NetworkInterface> ifs = null;
        try {
            ifs = NetworkInterface.getNetworkInterfaces();
        } catch (SocketException e1) {
            throw new IllegalStateException(
                    "Could not enumerate network interfaces!");
        }
        while (ifs.hasMoreElements()) {
            result.add(ifs.nextElement());
        }
        return result;
    }
}

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