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: 2000-12-06 13:26:52 -0800 (Wed, 06 Dec 2000) $'

 *  '$Revision: 584 $'

 */

package edu.ucsb.nceas.metacat;

import java.util.*;

import java.io.*;

import java.sql.*;

import java.net.*;

import java.lang.*;

import java.text.*;

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);

        }

        //System.out.println("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: " + e.getMessage());

      e.printStackTrace(System.out);

    }

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

  }

}