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/**
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* '$RCSfile$'
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* Purpose: A Class that implements replication for metacat
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* Copyright: 2000 Regents of the University of California and the
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* National Center for Ecological Analysis and Synthesis
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* Authors: Chad Berkley
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* Release: @release@
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*
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* '$Author: berkley $'
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* '$Date: 2001-01-18 15:15:21 -0800 (Thu, 18 Jan 2001) $'
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* '$Revision: 675 $'
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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package edu.ucsb.nceas.metacat;
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import java.util.*;
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import java.io.*;
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import java.sql.*;
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import java.net.*;
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import java.lang.*;
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import java.text.*;
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import javax.servlet.*;
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import javax.servlet.http.*;
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import org.xml.sax.*;
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public class MetacatReplication extends HttpServlet implements Runnable
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{
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private String deltaT;
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Timer replicationDaemon;
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private static MetaCatUtil util = new MetaCatUtil();
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private Vector fileLocks = new Vector();
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private Thread lockThread = null;
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/**
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* Initialize the servlet by creating appropriate database connections
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*/
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public void init(ServletConfig config) throws ServletException
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{
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//initialize db connections to handle any update requests
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MetaCatUtil util = new MetaCatUtil();
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deltaT = util.getOption("deltaT");
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//the default deltaT can be set from metacat.properties
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//create a thread to do the delta-T check but don't execute it yet
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replicationDaemon = new Timer(true);
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}
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public void destroy()
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{
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replicationDaemon.cancel();
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System.out.println("Replication daemon cancelled.");
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}
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public void doGet (HttpServletRequest request, HttpServletResponse response)
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throws ServletException, IOException
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{
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// Process the data and send back the response
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handleGetOrPost(request, response);
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}
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public void doPost(HttpServletRequest request, HttpServletResponse response)
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throws ServletException, IOException
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{
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// Process the data and send back the response
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handleGetOrPost(request, response);
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}
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private void handleGetOrPost(HttpServletRequest request,
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HttpServletResponse response)
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throws ServletException, IOException
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{
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PrintWriter out = response.getWriter();
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Hashtable params = new Hashtable();
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Enumeration paramlist = request.getParameterNames();
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while (paramlist.hasMoreElements())
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{
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String name = (String)paramlist.nextElement();
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String[] value = request.getParameterValues(name);
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params.put(name, value);
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}
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if(params.containsKey("action"))
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{
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if(((String[])params.get("action"))[0].equals("stop"))
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{ //stop the replication server
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replicationDaemon.cancel();
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replicationDaemon = new Timer(true);
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out.println("Replication Handler Stopped");
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System.out.println("Replication Handler Stopped");
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MetacatReplication.replLog("deltaT handler stopped");
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}
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else if(((String[])params.get("action"))[0].equals("start"))
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{ //start the replication server
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int rate;
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if(params.containsKey("rate"))
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{
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rate = new Integer(
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new String(((String[])params.get("rate"))[0])).intValue();
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if(rate < 30)
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{
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out.println("Replication deltaT rate cannot be less than 30!");
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//deltaT<30 is a timing mess!
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rate = 1000;
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}
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}
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else
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{
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rate = 1000;
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}
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out.println("New rate is: " + rate + " seconds.");
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replicationDaemon.cancel();
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replicationDaemon = new Timer(true);
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replicationDaemon.scheduleAtFixedRate(new ReplicationHandler(out), 0,
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rate * 1000);
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MetacatReplication.replLog("deltaT handler started with rate=" +
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rate + " seconds");
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out.println("Replication Handler Started");
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System.out.println("Replication Handler Started");
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}
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else if(((String[])params.get("action"))[0].equals("getall"))
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{ //updates this server exactly once
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replicationDaemon.schedule(new ReplicationHandler(out), 0);
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response.setContentType("text/html");
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out.println("<html><body>\"Get All\" Done</body></html>");
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}
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else if(((String[])params.get("action"))[0].equals("forcereplicate"))
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{
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handleForceReplicateRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("update"))
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{ //request an update list from the server
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handleUpdateRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("read"))
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{ //request a specific document from the server
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//note that this could be replaced by a call to metacatServlet
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//handleGetDocumentAction().
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handleGetDocumentRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("getlock"))
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{
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handleGetLockRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("getdocumentinfo"))
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{
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handleGetDocumentInfoRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("gettime"))
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{
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handleGetTimeRequest(out, params, response);
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}
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else if(((String[])params.get("action"))[0].equals("getcatalog"))
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{
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handleGetCatalogRequest(out, params, response, true);
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}
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else if(((String[])params.get("action"))[0].equals("servercontrol"))
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{
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handleServerControlRequest(out, params, response);
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}
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}
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}
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/**
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* This method can add, delete and list the servers currently included in
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* xml_replication.
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* action subaction other needed params
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* ---------------------------------------------------------
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* servercontrol add server
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* servercontrol delete server
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* servercontrol list
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*/
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private void handleServerControlRequest(PrintWriter out, Hashtable params,
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HttpServletResponse response)
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{
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String subaction = ((String[])params.get("subaction"))[0];
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try
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{
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Connection conn = util.openDBConnection();
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PreparedStatement pstmt = null;
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if(subaction.equals("add"))
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{
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String replicate = ((String[])params.get("replicate"))[0];
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String server = ((String[])params.get("server"))[0];
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pstmt = conn.prepareStatement("insert into xml_replication (server, " +
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"last_checked, replicate) values ('" + server + "', to_date(" +
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"'01/01/00', 'MM/DD/YY'), '" + replicate + "')");
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pstmt.execute();
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out.println("Server says: server " + server + " added");
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response.setContentType("text/html");
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out.println("<html><body><table border=\"1\">");
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out.println("<tr><td><b>server</b></td><td><b>last_checked</b></td><td>");
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out.println("<b>replicate</b></td></tr>");
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pstmt = conn.prepareStatement("select * from xml_replication");
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pstmt.execute();
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ResultSet rs = pstmt.getResultSet();
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boolean tablehasrows = rs.next();
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while(tablehasrows)
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{
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out.println("<tr><td>" + rs.getString(2) + "</td><td>");
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out.println(rs.getString(3) + "</td><td>");
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out.println(rs.getString(4) + "</td></tr>");
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tablehasrows = rs.next();
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}
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out.println("</table></body></html>");
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}
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else if(subaction.equals("delete"))
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{
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String server = ((String[])params.get("server"))[0];
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pstmt = conn.prepareStatement("delete from xml_replication where " +
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"server like '" + server + "'");
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pstmt.execute();
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out.println("Server says: server " + server + " deleted");
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response.setContentType("text/html");
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out.println("<html><body><table border=\"1\">");
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out.println("<tr><td><b>server</b></td><td><b>last_checked</b></td><td>");
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out.println("<b>replicate</b></td></tr>");
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pstmt = conn.prepareStatement("select * from xml_replication");
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pstmt.execute();
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ResultSet rs = pstmt.getResultSet();
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boolean tablehasrows = rs.next();
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while(tablehasrows)
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{
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out.println("<tr><td>" + rs.getString(2) + "</td><td>");
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out.println(rs.getString(3) + "</td><td>");
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out.println(rs.getString(4) + "</td></tr>");
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tablehasrows = rs.next();
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}
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out.println("</table></body></html>");
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}
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else if(subaction.equals("list"))
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{
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response.setContentType("text/html");
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out.println("<html><body><table border=\"1\">");
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out.println("<tr><td><b>server</b></td><td><b>last_checked</b></td><td>");
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out.println("<b>replicate</b></td></tr>");
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pstmt = conn.prepareStatement("select * from xml_replication");
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pstmt.execute();
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ResultSet rs = pstmt.getResultSet();
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boolean tablehasrows = rs.next();
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while(tablehasrows)
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{
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out.println("<tr><td>" + rs.getString(2) + "</td><td>");
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out.println(rs.getString(3) + "</td><td>");
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out.println(rs.getString(4) + "</td></tr>");
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tablehasrows = rs.next();
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}
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out.println("</table></body></html>");
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}
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pstmt.close();
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conn.close();
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}
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catch(Exception e)
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{
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System.out.println("error in " +
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"MetacatReplication.handleServerControlRequest " +
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e.getMessage());
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e.printStackTrace(System.out);
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}
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}
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/**
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* when a forcereplication request comes in, this method sends a read request
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* to the requesting server for the specified docid.
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*/
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private void handleForceReplicateRequest(PrintWriter out, Hashtable params,
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HttpServletResponse response)
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{
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//System.out.println("in handleforcereplicaterequest");
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String server = ((String[])params.get("server"))[0];
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if(!(replToServer(server)))
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{ //do not get the server's new document if we are not replicating from there
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return;
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}
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//the server that the request came from
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String docid = ((String[])params.get("docid"))[0];
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//the docid of the document to get
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String dbaction = "UPDATE";
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//default action is update
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boolean override = false;
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int serverCode = 1;
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try
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{
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if(params.containsKey("dbaction"))
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{ //if the url contains a dbaction then the default action is overridden
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dbaction = ((String[])params.get("dbaction"))[0];
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serverCode = MetacatReplication.getServerCode(server);
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override = true; //we are now overriding the default action
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}
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MetaCatUtil.debugMessage("action in forcereplicate is: " + dbaction);
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MetaCatUtil.debugMessage("serverCode in forcereplicate is: " + serverCode);
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MetacatReplication.replLog("force replication request from " + server);
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int serverCheckCode = MetacatReplication.getServerCode(server);
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URL u = new URL("http://" + server + "?action=read&docid=" + docid);
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MetaCatUtil.debugMessage("sending message: " + u.toString());
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String xmldoc = MetacatReplication.getURLContent(u);
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MetaCatUtil.debugMessage("document: " + xmldoc);
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//get the document to write
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URL docinfourl = new URL("http://" + server +
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"?action=getdocumentinfo&docid=" +
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docid);
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//we need to get the document's info so we can set the correct user
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//and group once we get the document and write it to our DB
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MetaCatUtil.debugMessage("sending message: " + docinfourl.toString());
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String docInfoStr = MetacatReplication.getURLContent(docinfourl);
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MetaCatUtil.debugMessage("docInfo: " + docInfoStr);
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DocInfoHandler dih = new DocInfoHandler();
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//dih is the parser for the docinfo xml format
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XMLReader docinfoParser = ReplicationHandler.initParser(dih);
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docinfoParser.parse(new InputSource(new StringReader(docInfoStr)));
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Hashtable docinfoHash = dih.getDocInfo();
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String user = (String)docinfoHash.get("user_owner");
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String group = new String(user);
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//right now the user and group are the same.
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Connection conn = util.openDBConnection();
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DocumentImpl.write(conn, new StringReader(xmldoc), null, dbaction, docid,
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user, group, serverCode, override);
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MetacatReplication.replLog("document " + docid + " added to DB with " +
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"action " + dbaction);
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conn.close();
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}
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catch(Exception e)
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{
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System.out.println("error in metacatReplication.handleForceReplicate" +
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"Request: " + e.getMessage());
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345
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}
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346
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}
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347
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348
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/**
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349
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* Grants or denies a lock to a requesting host.
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* The servlet parameters of interrest are:
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351
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* docid: the docid of the file the lock is being requested for
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352
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* currentdate: the timestamp of the document on the remote server
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*
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354
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*/
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355
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private void handleGetLockRequest(PrintWriter out, Hashtable params,
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356
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HttpServletResponse response)
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357
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{
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358
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try
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359
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{
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360
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Connection conn = util.openDBConnection();
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361
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String docid = ((String[])params.get("docid"))[0];
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String remoteRev = ((String[])params.get("updaterev"))[0];
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DocumentImpl requestDoc = new DocumentImpl(conn, docid);
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364
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MetacatReplication.replLog("lock request for " + docid);
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int localRevInt = requestDoc.getRev();
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int remoteRevInt = Integer.parseInt(remoteRev);
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367
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if(remoteRevInt >= localRevInt)
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{
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370
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if(!fileLocks.contains(docid))
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371
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{ //grant the lock if it is not already locked
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fileLocks.add(0, docid); //insert at the beginning of the queue Vector
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373
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//send a message back to the the remote host authorizing the insert
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out.println("<lockgranted><docid>" +docid+ "</docid></lockgranted>");
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lockThread = new Thread(this);
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376
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lockThread.setPriority(Thread.MIN_PRIORITY);
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lockThread.start();
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378
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System.out.println("lock granted for " + docid);
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MetacatReplication.replLog("lock granted for " + docid);
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380
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}
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381
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else
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{ //deny the lock
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out.println("<filelocked><docid>" + docid + "</docid></filelocked>");
|
384
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MetacatReplication.replLog("lock denied for " + docid +
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385
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"reason: file already locked");
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386
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}
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}
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else
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{//deny the lock.
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out.println("<outdatedfile><docid>" + docid + "</docid></filelocked>");
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MetacatReplication.replLog("lock denied for " + docid +
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392
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"reason: client has outdated file");
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393
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}
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394
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conn.close();
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395
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}
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396
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catch(Exception e)
|
397
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{
|
398
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System.out.println("error requesting file lock from MetacatReplication." +
|
399
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"handleGetLockRequest: " + e.getMessage());
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400
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e.printStackTrace(System.out);
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401
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}
|
402
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}
|
403
|
|
404
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/**
|
405
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* Sends all of the xml_documents information encoded in xml to a requestor
|
406
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* the format is:
|
407
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* <!ELEMENT documentinfo (docid, docname, doctype, doctitle, user_owner,
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408
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* user_updated, public_access, rev)
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409
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* all of the subelements of document info are #PCDATA
|
410
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*/
|
411
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private void handleGetDocumentInfoRequest(PrintWriter out, Hashtable params,
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412
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HttpServletResponse response)
|
413
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{
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414
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String docid = ((String[])(params.get("docid")))[0];
|
415
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StringBuffer sb = new StringBuffer();
|
416
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try
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417
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{
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418
|
Connection conn = util.openDBConnection();
|
419
|
DocumentImpl doc = new DocumentImpl(conn, docid);
|
420
|
sb.append("<documentinfo><docid>").append(docid);
|
421
|
sb.append("</docid><docname>").append(doc.getDocname());
|
422
|
sb.append("</docname><doctype>").append(doc.getDoctype());
|
423
|
sb.append("</doctype><doctitle>").append(doc.getDocTitle());
|
424
|
sb.append("</doctitle><user_owner>").append(doc.getUserowner());
|
425
|
sb.append("</user_owner><user_updated>").append(doc.getUserupdated());
|
426
|
sb.append("</user_updated><public_access>").append(doc.getPublicaccess());
|
427
|
sb.append("</public_access><rev>").append(doc.getRev());
|
428
|
sb.append("</rev></documentinfo>");
|
429
|
response.setContentType("text/xml");
|
430
|
out.println(sb.toString());
|
431
|
conn.close();
|
432
|
}
|
433
|
catch (Exception e)
|
434
|
{
|
435
|
System.out.println("error in " +
|
436
|
"metacatReplication.handlegetdocumentinforequest: " +
|
437
|
e.getMessage());
|
438
|
}
|
439
|
|
440
|
}
|
441
|
|
442
|
/**
|
443
|
* Sends a document to a remote host
|
444
|
*/
|
445
|
private void handleGetDocumentRequest(PrintWriter out, Hashtable params,
|
446
|
HttpServletResponse response)
|
447
|
{
|
448
|
try
|
449
|
{
|
450
|
String docid = ((String[])(params.get("docid")))[0];
|
451
|
MetaCatUtil.debugMessage("incoming get request for document: " + docid);
|
452
|
Connection conn = util.openDBConnection();
|
453
|
DocumentImpl di = new DocumentImpl(conn, docid);
|
454
|
response.setContentType("text/xml");
|
455
|
out.print(di.toString());
|
456
|
conn.close();
|
457
|
MetacatReplication.replLog("document " + docid + " sent");
|
458
|
System.out.println("document " + docid + " sent");
|
459
|
}
|
460
|
catch(Exception e)
|
461
|
{
|
462
|
System.out.println("error getting document from MetacatReplication." +
|
463
|
"handlGetDocumentRequest " + e.getMessage());
|
464
|
}
|
465
|
|
466
|
}
|
467
|
|
468
|
/**
|
469
|
* Sends a list of all of the documents on this sever along with their
|
470
|
* revision numbers.
|
471
|
* The format is:
|
472
|
* <!ELEMENT replication (server, updates)>
|
473
|
* <!ELEMENT server (#PCDATA)>
|
474
|
* <!ELEMENT updates ((updatedDocument | deleteDocument)*)>
|
475
|
* <!ELEMENT updatedDocument (docid, rev)>
|
476
|
* <!ELEMENT deletedDocument (docid, rev)>
|
477
|
* <!ELEMENT docid (#PCDATA)>
|
478
|
* <!ELEMENT rev (#PCDATA)>
|
479
|
* note that the rev in deletedDocument is always empty. I just left
|
480
|
* it in there to make the parser implementation easier.
|
481
|
*/
|
482
|
private void handleUpdateRequest(PrintWriter out, Hashtable params,
|
483
|
HttpServletResponse response)
|
484
|
{
|
485
|
try
|
486
|
{
|
487
|
System.out.println("received update request");
|
488
|
StringBuffer docsql = new StringBuffer();
|
489
|
StringBuffer doclist = new StringBuffer();
|
490
|
Vector packageFiles = new Vector();
|
491
|
|
492
|
//get all docs that reside on this server
|
493
|
doclist.append("<?xml version=\"1.0\"?><replication>");
|
494
|
doclist.append("<server>").append(util.getOption("server"));
|
495
|
doclist.append(util.getOption("replicationpath"));
|
496
|
doclist.append("</server><updates>");
|
497
|
|
498
|
docsql.append("select docid, rev, doctype from xml_documents where ");
|
499
|
docsql.append("server_location = 1");
|
500
|
|
501
|
//get any deleted documents
|
502
|
StringBuffer delsql = new StringBuffer();
|
503
|
delsql.append("select distinct docid from ");
|
504
|
delsql.append("xml_revisions where docid not in (select docid from ");
|
505
|
delsql.append("xml_documents) and server_location = 1");
|
506
|
|
507
|
Connection conn = util.openDBConnection();
|
508
|
PreparedStatement pstmt = conn.prepareStatement(docsql.toString());
|
509
|
pstmt.execute();
|
510
|
ResultSet rs = pstmt.getResultSet();
|
511
|
boolean tablehasrows = rs.next();
|
512
|
while(tablehasrows)
|
513
|
{
|
514
|
if(!rs.getString(3).equals(util.getOption("packagedoctype")))
|
515
|
{ //if this is a package file, put it at the end
|
516
|
//because if a package file is read before all of the files it
|
517
|
//refers to are loaded then there is an error
|
518
|
doclist.append("<updatedDocument>");
|
519
|
doclist.append("<docid>").append(rs.getString(1));
|
520
|
doclist.append("</docid><rev>").append(rs.getInt(2));
|
521
|
doclist.append("</rev>");
|
522
|
doclist.append("</updatedDocument>");
|
523
|
}
|
524
|
else
|
525
|
{ //the package files are saved to be put into the xml later.
|
526
|
Vector v = new Vector();
|
527
|
v.add(new String(rs.getString(1)));
|
528
|
v.add(new Integer(rs.getInt(2)));
|
529
|
packageFiles.add(new Vector(v));
|
530
|
}
|
531
|
tablehasrows = rs.next();
|
532
|
}
|
533
|
|
534
|
pstmt = conn.prepareStatement(delsql.toString());
|
535
|
pstmt.execute();
|
536
|
rs = pstmt.getResultSet();
|
537
|
tablehasrows = rs.next();
|
538
|
while(tablehasrows)
|
539
|
{ //handle the deleted documents
|
540
|
doclist.append("<deletedDocument><docid>").append(rs.getString(1));
|
541
|
doclist.append("</docid><rev></rev></deletedDocument>");
|
542
|
//note that rev is always empty for deleted docs
|
543
|
tablehasrows = rs.next();
|
544
|
}
|
545
|
|
546
|
//now we can put the package files into the xml results
|
547
|
for(int i=0; i<packageFiles.size(); i++)
|
548
|
{
|
549
|
Vector v = (Vector)packageFiles.elementAt(i);
|
550
|
doclist.append("<updatedDocument>");
|
551
|
doclist.append("<docid>").append((String)v.elementAt(0));
|
552
|
doclist.append("</docid><rev>");
|
553
|
doclist.append(((Integer)v.elementAt(1)).intValue());
|
554
|
doclist.append("</rev>");
|
555
|
doclist.append("</updatedDocument>");
|
556
|
}
|
557
|
|
558
|
doclist.append("</updates></replication>");
|
559
|
MetaCatUtil.debugMessage("doclist: " + doclist.toString());
|
560
|
pstmt.close();
|
561
|
conn.close();
|
562
|
response.setContentType("text/xml");
|
563
|
out.println(doclist.toString());
|
564
|
System.out.println("doclist: " + doclist.toString());
|
565
|
System.out.println("update request handled");
|
566
|
}
|
567
|
catch(Exception e)
|
568
|
{
|
569
|
System.out.println("error in MetacatReplication.handleupdaterequest: " +
|
570
|
e.getMessage());
|
571
|
e.printStackTrace(System.out);
|
572
|
}
|
573
|
|
574
|
}
|
575
|
|
576
|
/**
|
577
|
* Returns the xml_catalog table encoded in xml
|
578
|
*/
|
579
|
public static String getCatalogXML()
|
580
|
{
|
581
|
return handleGetCatalogRequest(null, null, null, false);
|
582
|
}
|
583
|
|
584
|
/**
|
585
|
* Sends the contents of the xml_catalog table encoded in xml
|
586
|
* The xml format is:
|
587
|
* <!ELEMENT xml_catalog (row*)>
|
588
|
* <!ELEMENT row (entry_type, source_doctype, target_doctype, public_id,
|
589
|
* system_id)>
|
590
|
* All of the sub elements of row are #PCDATA
|
591
|
|
592
|
* If printFlag == false then do not print to out.
|
593
|
*/
|
594
|
private static String handleGetCatalogRequest(PrintWriter out,
|
595
|
Hashtable params,
|
596
|
HttpServletResponse response,
|
597
|
boolean printFlag)
|
598
|
{
|
599
|
Connection conn = null;
|
600
|
PreparedStatement pstmt = null;
|
601
|
try
|
602
|
{
|
603
|
conn = util.openDBConnection();
|
604
|
pstmt = conn.prepareStatement("select entry_type, " +
|
605
|
"source_doctype, target_doctype, public_id, " +
|
606
|
"system_id from xml_catalog");
|
607
|
pstmt.execute();
|
608
|
ResultSet rs = pstmt.getResultSet();
|
609
|
boolean tablehasrows = rs.next();
|
610
|
StringBuffer sb = new StringBuffer();
|
611
|
sb.append("<?xml version=\"1.0\"?><xml_catalog>");
|
612
|
while(tablehasrows)
|
613
|
{
|
614
|
sb.append("<row><entry_type>").append(rs.getString(1));
|
615
|
sb.append("</entry_type><source_doctype>").append(rs.getString(2));
|
616
|
sb.append("</source_doctype><target_doctype>").append(rs.getString(3));
|
617
|
sb.append("</target_doctype><public_id>").append(rs.getString(4));
|
618
|
sb.append("</public_id><system_id>").append(rs.getString(5));
|
619
|
sb.append("</system_id></row>");
|
620
|
|
621
|
tablehasrows = rs.next();
|
622
|
}
|
623
|
sb.append("</xml_catalog>");
|
624
|
conn.close();
|
625
|
if(printFlag)
|
626
|
{
|
627
|
response.setContentType("text/xml");
|
628
|
out.println(sb.toString());
|
629
|
}
|
630
|
pstmt.close();
|
631
|
return sb.toString();
|
632
|
}
|
633
|
catch(Exception e)
|
634
|
{
|
635
|
try
|
636
|
{
|
637
|
pstmt.close();
|
638
|
conn.close();
|
639
|
}
|
640
|
catch(Exception ee)
|
641
|
{}
|
642
|
System.out.println("error in MetacatReplication.handleGetCatalogRequest:"+
|
643
|
e.getMessage());
|
644
|
e.printStackTrace(System.out);
|
645
|
}
|
646
|
return null;
|
647
|
}
|
648
|
|
649
|
/**
|
650
|
* Sends the current system date to the remote server. Using this action
|
651
|
* for replication gets rid of any problems with syncronizing clocks
|
652
|
* because a time specific to a document is always kept on its home server.
|
653
|
*/
|
654
|
private void handleGetTimeRequest(PrintWriter out, Hashtable params,
|
655
|
HttpServletResponse response)
|
656
|
{
|
657
|
SimpleDateFormat formatter = new SimpleDateFormat ("yy-MM-dd HH:mm:ss");
|
658
|
java.util.Date localtime = new java.util.Date();
|
659
|
String dateString = formatter.format(localtime);
|
660
|
response.setContentType("text/xml");
|
661
|
|
662
|
out.println("<timestamp>" + dateString + "</timestamp>");
|
663
|
}
|
664
|
|
665
|
/**
|
666
|
* this method handles the timeout for a file lock. when a lock is
|
667
|
* granted it is granted for 30 seconds. When this thread runs out
|
668
|
* it deletes the docid from the queue, thus eliminating the lock.
|
669
|
*/
|
670
|
public void run()
|
671
|
{
|
672
|
try
|
673
|
{
|
674
|
MetaCatUtil.debugMessage("thread started for docid: " +
|
675
|
(String)fileLocks.elementAt(0));
|
676
|
System.out.println("thread started for docid: " +
|
677
|
(String)fileLocks.elementAt(0));
|
678
|
Thread.sleep(30000); //the lock will expire in 30 seconds
|
679
|
MetaCatUtil.debugMessage("thread for docid: " +
|
680
|
(String)fileLocks.elementAt(fileLocks.size() - 1) +
|
681
|
" exiting.");
|
682
|
System.out.println("thread for docid: " +
|
683
|
(String)fileLocks.elementAt(fileLocks.size() - 1) +
|
684
|
" exiting.");
|
685
|
fileLocks.remove(fileLocks.size() - 1);
|
686
|
//fileLocks is treated as a FIFO queue. If there are more than one lock
|
687
|
//in the vector, the first one inserted will be removed.
|
688
|
}
|
689
|
catch(Exception e)
|
690
|
{
|
691
|
System.out.println("error in file lock thread from MetacatReplication." +
|
692
|
"run: " + e.getMessage());
|
693
|
}
|
694
|
}
|
695
|
|
696
|
/**
|
697
|
* Returns the name of a server given a serverCode
|
698
|
* @param serverCode the serverid of the server
|
699
|
* @return the servername or null if the specified serverCode does not
|
700
|
* exist.
|
701
|
*/
|
702
|
public static String getServer(int serverCode)
|
703
|
{
|
704
|
//System.out.println("serverid: " + serverCode);
|
705
|
try
|
706
|
{
|
707
|
Connection conn = util.openDBConnection();
|
708
|
String sql = new String("select server from " +
|
709
|
"xml_replication where serverid = " +
|
710
|
serverCode);
|
711
|
PreparedStatement pstmt = conn.prepareStatement(sql);
|
712
|
//System.out.println("getserver sql: " + sql);
|
713
|
pstmt.execute();
|
714
|
ResultSet rs = pstmt.getResultSet();
|
715
|
boolean tablehasrows = rs.next();
|
716
|
if(tablehasrows)
|
717
|
{
|
718
|
//System.out.println("server: " + rs.getString(1));
|
719
|
return rs.getString(1);
|
720
|
}
|
721
|
pstmt.close();
|
722
|
conn.close();
|
723
|
}
|
724
|
catch(Exception e)
|
725
|
{
|
726
|
System.out.println("Error in MetacatReplication.getServer: " +
|
727
|
e.getMessage());
|
728
|
}
|
729
|
return null;
|
730
|
//return null if the server does not exist
|
731
|
}
|
732
|
|
733
|
/**
|
734
|
* Returns a server code given a server name
|
735
|
* @param server the name of the server
|
736
|
* @return integer > 0 representing the code of the server, 0 if the server
|
737
|
* does not exist.
|
738
|
*/
|
739
|
public static int getServerCode(String server) throws Exception
|
740
|
{
|
741
|
Connection conn = null;
|
742
|
PreparedStatement pstmt = null;
|
743
|
try
|
744
|
{
|
745
|
conn = util.openDBConnection();
|
746
|
pstmt = conn.prepareStatement("select serverid from " +
|
747
|
"xml_replication where server " +
|
748
|
"like '" + server + "'");
|
749
|
pstmt.execute();
|
750
|
ResultSet rs = pstmt.getResultSet();
|
751
|
boolean tablehasrows = rs.next();
|
752
|
int serverCode = 0;
|
753
|
if(tablehasrows)
|
754
|
{
|
755
|
int ret = rs.getInt(1);
|
756
|
pstmt.close();
|
757
|
conn.close();
|
758
|
return ret;
|
759
|
}
|
760
|
else
|
761
|
{
|
762
|
pstmt.close();
|
763
|
conn.close();
|
764
|
return 0;
|
765
|
}
|
766
|
}
|
767
|
catch(Exception e)
|
768
|
{
|
769
|
throw e;
|
770
|
}
|
771
|
finally
|
772
|
{
|
773
|
try
|
774
|
{
|
775
|
pstmt.close();
|
776
|
conn.close();
|
777
|
}
|
778
|
catch(Exception ee) {}
|
779
|
}
|
780
|
}
|
781
|
|
782
|
/**
|
783
|
* This method returns the content of a url
|
784
|
* @param u the url to return the content from
|
785
|
* @return a string representing the content of the url
|
786
|
* @throws java.io.IOException
|
787
|
*/
|
788
|
public static String getURLContent(URL u) throws java.io.IOException
|
789
|
{
|
790
|
//System.out.println("url: " + u.toString());
|
791
|
char istreamChar;
|
792
|
int istreamInt;
|
793
|
InputStreamReader istream = new InputStreamReader(u.openStream());
|
794
|
StringBuffer serverResponse = new StringBuffer();
|
795
|
while((istreamInt = istream.read()) != -1)
|
796
|
{
|
797
|
istreamChar = (char)istreamInt;
|
798
|
serverResponse.append(istreamChar);
|
799
|
}
|
800
|
|
801
|
return serverResponse.toString();
|
802
|
}
|
803
|
|
804
|
/**
|
805
|
* Method for writing replication messages to a log file specified in
|
806
|
* metacat.properties
|
807
|
*/
|
808
|
public static void replLog(String message)
|
809
|
{
|
810
|
try
|
811
|
{
|
812
|
FileOutputStream fos = new FileOutputStream(
|
813
|
util.getOption("replicationlog"), true);
|
814
|
PrintWriter pw = new PrintWriter(fos);
|
815
|
SimpleDateFormat formatter = new SimpleDateFormat ("yy-MM-dd HH:mm:ss");
|
816
|
java.util.Date localtime = new java.util.Date();
|
817
|
String dateString = formatter.format(localtime);
|
818
|
dateString += " :: " + message;
|
819
|
//time stamp each entry
|
820
|
pw.println(dateString);
|
821
|
pw.flush();
|
822
|
}
|
823
|
catch(Exception e)
|
824
|
{
|
825
|
System.out.println("error writing to replication log from " +
|
826
|
"MetacatReplication.replLog: " + e.getMessage());
|
827
|
//e.printStackTrace(System.out);
|
828
|
}
|
829
|
}
|
830
|
|
831
|
/**
|
832
|
* Returns true if the replicate field for server in xml_replication is 1.
|
833
|
* Returns false otherwise
|
834
|
*/
|
835
|
public static boolean replToServer(String server)
|
836
|
{
|
837
|
Connection conn = null;
|
838
|
PreparedStatement pstmt = null;
|
839
|
try
|
840
|
{
|
841
|
conn = util.openDBConnection();
|
842
|
pstmt = conn.prepareStatement("select replicate from " +
|
843
|
"xml_replication where server like '" +
|
844
|
server + "'");
|
845
|
pstmt.execute();
|
846
|
ResultSet rs = pstmt.getResultSet();
|
847
|
boolean tablehasrows = rs.next();
|
848
|
if(tablehasrows)
|
849
|
{
|
850
|
int i = rs.getInt(1);
|
851
|
if(i == 1)
|
852
|
{
|
853
|
pstmt.close();
|
854
|
conn.close();
|
855
|
return true;
|
856
|
}
|
857
|
else
|
858
|
{
|
859
|
pstmt.close();
|
860
|
conn.close();
|
861
|
return false;
|
862
|
}
|
863
|
}
|
864
|
}
|
865
|
catch(Exception e)
|
866
|
{
|
867
|
System.out.println("error in MetacatReplication.replToServer: " +
|
868
|
e.getMessage());
|
869
|
}
|
870
|
finally
|
871
|
{
|
872
|
try
|
873
|
{
|
874
|
pstmt.close();
|
875
|
conn.close();
|
876
|
}
|
877
|
catch(Exception ee)
|
878
|
{}
|
879
|
}
|
880
|
return false;
|
881
|
//the default if this server does not exist is to not replicate to it.
|
882
|
}
|
883
|
}
|