Java Ping ping(String url, int timeout)

Description

Pings a HTTP URL.

License

GNU General Public License

Parameter

Parameter	Description
url	The HTTP URL to be pinged.
timeout	The timeout in millis for both the connection timeout and the response read timeout. Note that the total timeout is effectively two times the given timeout.

Return

true if the given HTTP URL has returned response code 200-399 on a HEAD request within the given timeout, otherwise false.

Declaration

public static boolean ping(String url, int timeout) 

Method Source Code

//package com.java2s;
/**/*  www  .  j a v a  2s .  com*/
 * BioJava development code
 *
 * This code may be freely distributed and modified under the terms of the GNU
 * Lesser General Public Licence. This should be distributed with the code. If
 * you do not have a copy, see:
 *
 * http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual authors. These
 * should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims, or to join the
 * biojava-l mailing list, visit the home page at:
 *
 * http://www.biojava.org/
 *
 * Created on Feb 23, 2012 Created by Andreas Prlic
 *
 * @since 3.0.2
 */

import java.io.IOException;

import java.net.HttpURLConnection;

import java.net.URL;
import java.net.URLConnection;

public class Main {
    /**
     * Pings a HTTP URL. This effectively sends a HEAD request and returns
     * <code>true</code> if the response code is in the 200-399 range.
     *
     * @param url The HTTP URL to be pinged.
     * @param timeout The timeout in millis for both the connection timeout and
     * the response read timeout. Note that the total timeout is effectively two
     * times the given timeout.
     * @return <code>true</code> if the given HTTP URL has returned response
     * code 200-399 on a HEAD request within the given timeout, otherwise
     * <code>false</code>.
     * @author BalusC,
     * http://stackoverflow.com/questions/3584210/preferred-java-way-to-ping-a-http-url-for-availability
     */
    public static boolean ping(String url, int timeout) {
        //url = url.replaceFirst("https", "http"); // Otherwise an exception may be thrown on invalid SSL certificates.

        try {
            HttpURLConnection connection = (HttpURLConnection) prepareURLConnection(url, timeout);
            connection.setRequestMethod("HEAD");
            int responseCode = connection.getResponseCode();
            return (200 <= responseCode && responseCode <= 399);
        } catch (IOException exception) {
            return false;
        }
    }

    /**
     * Prepare {@link URLConnection} with customised timeouts.
     *
     * @param url The URL
     * @param timeout The timeout in millis for both the connection timeout and
     * the response read timeout. Note that the total timeout is effectively two
     * times the given timeout.
     *
     * <p>
     * Example of code.      <code>
    * UrlConnection conn = prepareURLConnection("http://www.google.com/", 20000);
     * conn.connect();
     * conn.getInputStream();
     * </code>
     * <p>
     *
     * <bold>NB. User should execute connect() method before getting input
     * stream.</bold>
     * @return
     * @throws IOException
     * @author Jacek Grzebyta
     */
    public static URLConnection prepareURLConnection(String url, int timeout) throws IOException {
        URLConnection connection = new URL(url).openConnection();
        connection.setReadTimeout(timeout);
        connection.setConnectTimeout(timeout);
        return connection;
    }
}

Related

1. ping(String ip)
2. ping(String url, int timeout)
3. pingHost(String host)
4. pingHttp(URL url, int retry, int timeout)
5. pingUrl(final String address)