Has URLContent Changed

    
/**********************************************************************************

    Feedzeo! 
    A free and open source RSS/Atom/RDF feed aggregator

    Copyright (C) 2005-2006  Anand Rao (anandrao@users.sourceforge.net)

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

************************************************************************************/


/*
 * HttpUtil.java
 *
 * Created on November 12, 2005, 9:12 PM
 */


import java.util.*;
import java.net.*;

/**
 *
 * @author  Anand Rao
 */
public class HttpUtil {

  
    public static boolean hasURLContentChanged(String url, long fromtime)
    {
        URL Url; HttpURLConnection httpconn=null; long modtime;
        boolean contentChanged=false;
        try {
            Url = new URL(url);
            httpconn = (HttpURLConnection) Url.openConnection();
            modtime = httpconn.getLastModified();
            if ((modtime > fromtime) || (modtime <= 0)) {
                System.out.println("*** Old Link time:"+new Date(fromtime).toString()+
                                    " New link time:"+new Date(modtime).toString());
                contentChanged=true;
            }
        }
        catch (Exception e) {
            contentChanged=true; // assume content has changed
        }
        if (httpconn != null)
            httpconn.disconnect();
        return contentChanged;
    }
    
    public static long getURLLastModified(String url)
    {
        URL Url; HttpURLConnection httpconn=null; long modtime;
        try {
            Url = new URL(url);
            httpconn = (HttpURLConnection) Url.openConnection();
            modtime = httpconn.getLastModified();
        }
        catch (Exception e) {
            modtime = -1;
        }
        if (httpconn != null)
            httpconn.disconnect();
        System.out.println("URL:"+url+" LastModified:" + 
                           new Date(modtime).toString());
        return modtime;
    }

    public static String getDomainName(String url)
    {
         URL u;
         try {
             u = new URL(url);
         } 
         catch (Exception e) { 
             return "";
         }
         return u.getHost();
    }

}

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Has URLContent Changed : URL « Network Protocol « Java

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