Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A class to asyncronously force the replication of each server 

 *             that has an entry in the xml_replication table.  When run, 

 *             this thread communicates with each server in the list and 

 *             solicites a read of an updated or newly inserted document 

 *             with a certain docid.

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Chad Berkley

 *    Release: @release@

 *

 *   '$Author: berkley $'

 *     '$Date: 2001-01-18 15:15:21 -0800 (Thu, 18 Jan 2001) $'

 * '$Revision: 675 $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat;

import java.util.*;

import java.io.*;

import java.sql.*;

import java.net.*;

import java.lang.*;

import java.text.*;

/**

 * A class to asyncronously force the replication of each server 

 * that has an entry in the xml_replication table.  When run, 

 * this thread communicates with each server in the list and 

 * solicites a read of an updated or newly inserted document 

 * with a certain docid.

 */

public class ForceReplicationHandler implements Runnable

{

  private Thread btThread;

  private Connection conn;

  private MetaCatUtil util = new MetaCatUtil();

  private String docid;

  private String action;

  private boolean dbactionFlag = true;

  /**

   * @param docid the docid to force replicate

   * @param the action that is being performed on the document (either 

   *        INSERT or UPDATE)

   */

  public ForceReplicationHandler(String docid, String action)

  {

    this.docid = docid;

    this.action = action;

    if(this.action.equals(""))

    {

      dbactionFlag = false;

    }

    btThread = new Thread(this);

    btThread.setPriority(Thread.MIN_PRIORITY);

    btThread.start();

  }

  /**

   * Use this constructor when the action is implied.

   */

  public ForceReplicationHandler(String docid)

  {

    this.docid = docid;

    dbactionFlag = false;

    btThread = new Thread(this);

    btThread.setPriority(Thread.MIN_PRIORITY);

    btThread.start();

  }

  public void run()

  {

    //System.out.println("in ForceReplicationHandler Thread");

    try

    {

      URL comeAndGetIt;

      conn = util.openDBConnection();

      Enumeration keys = (ReplicationHandler.buildServerList(conn)).keys();

      //get the list of servers

      while(keys.hasMoreElements())

      {

        String server = (String)(keys.nextElement());

        if(dbactionFlag)

        {

          MetacatReplication.replLog("force replicating to " + server);

          comeAndGetIt = new URL("http://" + server + 

                                 "?action=forcereplicate&server=" + 

                                 util.getOption("server") + 

                                 util.getOption("replicationpath") +

                                 "&docid=" + docid + "&dbaction=" +

                                  action);

        }

        else

        {

          MetacatReplication.replLog("force replicating (default action) to )" + 

                                      server);

          comeAndGetIt = new URL("http://" + server + 

                                 "?action=forcereplicate&server=" + 

                                 util.getOption("server") + 

                                 util.getOption("replicationpath") +

                                 "&docid=" + docid);

        }

        MetaCatUtil.debugMessage("sending message: " + comeAndGetIt.toString());

        String message = MetacatReplication.getURLContent(comeAndGetIt);

        //send out the url.  message is a dummy variable as the target of

        //the URL never directly replies to the request.  this simply

        //invoces a read request from the server to this local machine.

      }

      conn.close();

    }

    catch(Exception e)

    {

      System.out.println("error in ForceReplicationHandler.run: " + 

                          e.getMessage());

      e.printStackTrace(System.out);

    }

    MetaCatUtil.debugMessage("exiting ForceReplicationHandler Thread");

  }

}