Ping.java

/**
 * Copyright (c) 2014-2017 by the respective copyright holders.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.eclipse.smarthome.model.script.actions;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketTimeoutException;

/**
 * This Action checks the vitality of the given host.
 *
 * @author Thomas.Eichstaedt-Engelen
 * @author Kai Kreuzer
 */
public class Ping {

    /**
     * Checks the vitality of <code>host</code>. If <code>port</code> '0'
     * is specified (which is the default when configuring just the host), a
     * regular ping is issued. If other ports are specified we try open a new
     * Socket with the given <code>timeout</code>.
     * 
     * @param host
     * @param port
     * @param timeout
     * 
     * @return <code>true</code> when <code>host</code> is reachable on <code>port</code> within the given
     *         <code>timeout</code> and <code>false</code> in all other
     *         cases.
     * 
     * @throws IOException
     * @throws SocketTimeoutException
     */
    public static boolean checkVitality(String host, int port, int timeout) throws IOException, SocketTimeoutException {
        boolean success = false;

        if (host != null && timeout > 0) {
            if (port == 0) {
                success = InetAddress.getByName(host).isReachable(timeout);
            } else {
                SocketAddress socketAddress = new InetSocketAddress(host, port);

                Socket socket = new Socket();
                socket.connect(socketAddress, timeout);
                success = true;
                socket.close();
            }
        }

        return success;
    }

}