/*
 * Copyright (c) 2003-onwards Shaven Puppy Ltd
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Shaven Puppy' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.shavenpuppy.jglib.util;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Enumeration;

/**
 * A utility class to check to see if the user is online.
 */
public final class CheckOnline {

	/**
	 * No constructor
	 */
	private CheckOnline() {
	}

	/**
	 * @return true if we think the user is online
	 */
	public static boolean isOnline() {
		boolean found = false;
		try {
			outer : for (Enumeration<NetworkInterface> ni = NetworkInterface.getNetworkInterfaces(); ni.hasMoreElements();) {
				NetworkInterface nif = ni.nextElement();
				for (Enumeration<InetAddress> ina = nif.getInetAddresses(); ina.hasMoreElements();) {
					InetAddress inadr = ina.nextElement();
					if (inadr.isAnyLocalAddress() || inadr.isLoopbackAddress() || inadr.isMulticastAddress()) {
						continue;
					} else {
						found = true;
						break outer;
					}
				}
			}
		} catch (Exception e) {
			return false;
		}
		return found;
	}

}