source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/collection/Collection.java@ 36976

/*
 *    Collection.java
 *    Copyright (C) 2002 New Zealand Digital Library, http://www.nzdl.org
 *
 *    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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.gsdl3.collection;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.greenstone.gsdl3.core.ModuleInterface;
import org.greenstone.gsdl3.service.Authentication;
import org.greenstone.gsdl3.util.CustomClassLoader;
import org.greenstone.gsdl3.util.Dictionary;
import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.GSXSLT;
import org.greenstone.gsdl3.util.OAIXML;
import org.greenstone.gsdl3.util.SimpleMacroResolver;
import org.greenstone.gsdl3.util.UserContext;
import org.greenstone.gsdl3.util.XMLConverter;
import org.greenstone.gsdl3.util.XMLTransformer;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Represents a collection in Greenstone. A collection is an extension of a
 * ServiceCluster - it has local data that the services use.
 * 
 * @author Katherine Don
 * @see ModuleInterface
 */
public class Collection extends ServiceCluster
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.collection.Collection.class.getName());

    /** is this collection being tidied and therefore can support realistic book view? */
    protected boolean useBook = false;
    /**
     * is this collection public or private - public collections will
     * appear on the home page, whereas private collections won't
     */
    protected boolean is_public = true;
    /** collection type : mg, mgpp or lucene */
    protected String col_type = "";
    /** database type : gdbm, jdbm or sqlite */
    protected String db_type = "";
    /** time when this collection was built Used by RSS */
    protected long lastmodified = 0;
    /** earliestDatestamp of this collection. Used by RSS. No longer used as fallback by OAI */
        protected long earliestDatestamp = 0;

    /** Stores the default accessibility of guest users */
    protected boolean _publicAccess = true;
    /** Stores the scope of any security rules (either collection or document) */
    protected boolean _securityScopeCollection = true;
        protected String _humanVerify = null;
        protected boolean _useRecaptcha = false; // for human verify
        protected String _siteKey = null; // for recaptcha
        protected String _secretKey = null; // for recaptcha
  
    protected HashMap<String, ArrayList<Element>> _documentSets = new HashMap<String, ArrayList<Element>>();
    protected ArrayList<HashMap<String, ArrayList<String>>> _securityExceptions = new ArrayList<HashMap<String, ArrayList<String>>>();

    protected XMLTransformer transformer = null;

    /** same as setClusterName */
    public void setCollectionName(String name)
    {
        setClusterName(name);
    }

    public Collection()
    {
        super();
        this.description = this.desc_doc.createElement(GSXML.COLLECTION_ELEM);
    }

    /**
     * Configures the collection.
     * 
     * gsdlHome and collectionName must be set before configure is called.
     * 
     * the file buildcfg.xml is located in gsdlHome/collect/collectionName
     * collection metadata is obtained, and services loaded.
     * 
     * @return true/false on success/fail
     */
    public boolean configure()
    {
        if (this.site_home == null || this.cluster_name == null)
        {
            logger.error("Collection: site_home and collection_name must be set before configure called!");
            return false;
        }
        // set up the class loader
        this.class_loader = new CustomClassLoader(this.getClass().getClassLoader(), GSFile.collectionResourceDir(this.site_home, this.cluster_name));

        macro_resolver.addMacro("_httpcollection_", this.site_http_address + "/collect/" + this.cluster_name);

        Element coll_config_xml = loadCollConfigFile();
        if (coll_config_xml == null) {
          logger.error("Collection: couldn't configure collection: " + this.cluster_name + ", " + "Couldn't load collection config file");

          return false;
        }
        Element build_config_xml = loadBuildConfigFile();

        if (build_config_xml == null)
        {
          logger.error("Collection: couldn't configure collection: " + this.cluster_name + ", " + "Couldn't load build config file");

          return false;
        }

        GSXSLT.modifyCollectionConfigForDebug(coll_config_xml);
        // get the collection type attribute
        Element search = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.SEARCH_ELEM);
        if (search != null)
        {
            col_type = search.getAttribute(GSXML.TYPE_ATT);
        }

        Element browse = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.INFODB_ELEM);
        if (browse != null)
        {
            db_type = browse.getAttribute(GSXML.TYPE_ATT);
        }
        else
        {
            db_type = "gdbm"; //Default database type
        }

        this.description.setAttribute(GSXML.TYPE_ATT, col_type);
        this.description.setAttribute(GSXML.DB_TYPE_ATT, db_type);

        _globalFormat = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.FORMAT_ELEM);
        // process the metadata and display items and default library params
        super.configureLocalData(coll_config_xml);
        super.configureLocalData(build_config_xml);
        // get extra collection specific stuff
        findAndLoadInfo(coll_config_xml, build_config_xml);

        loadSecurityInformation(coll_config_xml);

        // do we have archives folder?
        File archives_folder = new File(GSFile.collectionArchiveDir(this.site_home, this.cluster_name));
        if (!archives_folder.exists()) {
          this.description.setAttribute(GSXML.NO_ARCHIVES_ATT, "true");
        }
        // now do the services
        configureServiceRacks(coll_config_xml, build_config_xml);

        return true;

    }

    public boolean useBook()
    {
        return useBook;
    }

    public boolean isPublic()
    {
        return is_public;
    }

    // Used by RSSRetrieve. No longer used by OAI Receptionist (as second fallback)
    public long getLastmodified()
    {
        return lastmodified;
    }

    // used by RSSRetrieve, no longer used as fallback by the OAIReceptionist
    public long getEarliestDatestamp()
    {
        return earliestDatestamp;
    }

    /**
     * load in the collection config file into a DOM Element
     */
    protected Element loadCollConfigFile()
    {

        File coll_config_file = new File(GSFile.collectionConfigFile(this.site_home, this.cluster_name));

        if (!coll_config_file.exists())
        {
            logger.error("@@@ File " + coll_config_file + " did not exist. Can't load it in");
            return null;
        }
        // get the xml
        Document coll_config_doc = this.converter.getDOM(coll_config_file, CONFIG_ENCODING);
        Element coll_config_elem = null;
        if (coll_config_doc != null)
        {
            coll_config_elem = coll_config_doc.getDocumentElement();
        }
        return coll_config_elem;

    }

    /**
     * load in the collection build config file into a DOM Element
     */
    protected Element loadBuildConfigFile()
    {
        File build_config_file = new File(GSFile.collectionBuildConfigFile(this.site_home, this.cluster_name));
        if (!build_config_file.exists())
        {
            logger.error("Collection: couldn't configure collection: " + this.cluster_name + ", " + build_config_file + " does not exist");
            return null;
        }
        Document build_config_doc = this.converter.getDOM(build_config_file, CONFIG_ENCODING);
        Element build_config_elem = null;
        if (build_config_doc != null)
        {
            build_config_elem = build_config_doc.getDocumentElement();
        }

        lastmodified = build_config_file.lastModified();

        return build_config_elem;
    }

    /**
     * find the metadata and display elems from the two config files and add it
     * to the appropriate lists
     */
    protected boolean findAndLoadInfo(Element coll_config_xml, Element build_config_xml)
    {
      addMetadata("httpPath", this.site_http_address + "/collect/" + this.cluster_name);


        //check whether the html are tidy or not
        Element import_list = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.IMPORT_ELEM);
        if (import_list != null)
        {
            Element plugin_list = (Element) GSXML.getChildByTagName(import_list, GSXML.PLUGIN_ELEM + GSXML.LIST_MODIFIER);
            //addPlugins(plugin_list);
            if (plugin_list != null)
            {
                Element plugin_elem = (Element) GSXML.getNamedElement(plugin_list, GSXML.PLUGIN_ELEM, GSXML.NAME_ATT, "HTMLPlugin");
                if (plugin_elem != null)
                {
                    //get the option
                    Element option_elem = (Element) GSXML.getNamedElement(plugin_elem, GSXML.PARAM_OPTION_ELEM, GSXML.NAME_ATT, "-use_realistic_book");
                    if (option_elem != null)
                    {
                        useBook = true;
                    }
                }
            }
        }
        String tidy = (useBook == true ? "tidy" : "untidy");
        addMetadata("tidyoption", tidy);

        
        if (this.metadata_list != null)
        {
          // check whether we are public or not
            Element meta_elem = (Element) GSXML.getNamedElement(this.metadata_list, GSXML.METADATA_ELEM, GSXML.NAME_ATT, "public");
            if (meta_elem != null)
            {
                String value = GSXML.getValue(meta_elem).toLowerCase().trim();
                if (value.equals("false"))
                {
                    is_public = false;
                }
            }
            // earliest datestamp is the time the collection was created.
            meta_elem = (Element) GSXML.getNamedElement(this.metadata_list, GSXML.METADATA_ELEM, GSXML.NAME_ATT, OAIXML.EARLIEST_DATESTAMP);
            if (meta_elem != null) {
              String earliestDatestampStr = GSXML.getValue(meta_elem);
              if (!earliestDatestampStr.equals("")) {
                  earliestDatestamp = Long.parseLong(earliestDatestampStr) * 1000; // stored in seconds, convert to milliseconds
              }
            }
        
        }
        return true;
    }

    protected void loadSecurityInformation(Element coll_config_xml)
    {
        Element securityBlock = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.SECURITY_ELEM);

        if (securityBlock == null)
        {
            return;
        }

        String disabled = securityBlock.getAttribute(GSXML.DISABLED_ATT);
        if (!disabled.equals("")) {
          // security block has been disabled.
          logger.warn("Security block has been disabled. Not implementing any security for collection "+this.cluster_name);
          return;
        }
        String scope = securityBlock.getAttribute(GSXML.SCOPE_ATT);
        String defaultAccess = securityBlock.getAttribute(GSXML.DEFAULT_ACCESS_ATT);

        if (defaultAccess.toLowerCase().equals(GSXML.ACCESS_PUBLIC))
        {
            _publicAccess = true;
        }
        else if (defaultAccess.toLowerCase().equals(GSXML.ACCESS_PRIVATE))
        {
            _publicAccess = false;
        }
        else
        {
            logger.warn("Default access for collection " + this.cluster_name + " is neither public nor private, assuming public");
        }

        String humanVerify = securityBlock.getAttribute(GSXML.VERIFY_ATT);
        if (!humanVerify.equals("") && !humanVerify.equals("false")) {
          _humanVerify = humanVerify;
        }

        String useRecaptcha = securityBlock.getAttribute(GSXML.USE_RECAPTCHA_ATT);
        if (useRecaptcha.equals("true")) {

          Authentication authen_services =(Authentication) this.router.getModuleMap().get(Authentication.AUTHENTICATION_SERVICE);
          if (authen_services != null) {
            String siteKey = authen_services.getRecaptchaSiteKey();
            String secretKey = authen_services.getRecaptchaSecretKey();

            if (siteKey != null && secretKey != null) {
              _useRecaptcha = true;
              _siteKey = siteKey;
              _secretKey = secretKey;
            } else {
              logger.warn("use_recaptcha was set to true, but couldn't find recaptcha site and secret keys from the siteConfig Authentication service. Setting use_recaptcha to false!");
            }
          }
        }
        if (scope.toLowerCase().equals(GSXML.SCOPE_COLLECTION))
        {
            _securityScopeCollection = true;
        }
        else if (scope.toLowerCase().equals(GSXML.SCOPE_DOCUMENT))
        {
            _securityScopeCollection = false;
        }
        else
        {
            logger.warn("Security scope is neither collection nor document, assuming collection");
        }

        NodeList exceptions = GSXML.getChildrenByTagName(securityBlock, GSXML.EXCEPTION_ELEM);

        if (exceptions.getLength() > 0)
        {
            if (!_securityScopeCollection)
            {
                NodeList documentSetElems = GSXML.getChildrenByTagName(securityBlock, GSXML.DOCUMENT_SET_ELEM);
                for (int i = 0; i < documentSetElems.getLength(); i++)
                {
                    Element documentSet = (Element) documentSetElems.item(i);
                    String setName = documentSet.getAttribute(GSXML.NAME_ATT);
                    NodeList matchStatements = GSXML.getChildrenByTagName(documentSet, GSXML.MATCH_ELEM);
                    ArrayList<Element> matchStatementList = new ArrayList<Element>();
                    for (int j = 0; j < matchStatements.getLength(); j++)
                    {
                        matchStatementList.add((Element) matchStatements.item(j));
                    }
                    _documentSets.put(setName, matchStatementList);
                }
            }

            for (int i = 0; i < exceptions.getLength(); i++)
            {
                HashMap<String, ArrayList<String>> securityException = new HashMap<String, ArrayList<String>>();
                ArrayList<String> exceptionGroups = new ArrayList<String>();
                ArrayList<String> exceptionSets = new ArrayList<String>();

                Element exception = (Element) exceptions.item(i);
                NodeList groups = GSXML.getChildrenByTagName(exception, GSXML.GROUP_ELEM);
                for (int j = 0; j < groups.getLength(); j++)
                {
                    Element group = (Element) groups.item(j);
                    String groupName = group.getAttribute(GSXML.NAME_ATT);
                    exceptionGroups.add(groupName);
                }
                NodeList docSets = GSXML.getChildrenByTagName(exception, GSXML.DOCUMENT_SET_ELEM);
                for (int j = 0; j < docSets.getLength(); j++)
                {
                    Element docSet = (Element) docSets.item(j);
                    String docSetName = docSet.getAttribute(GSXML.NAME_ATT);
                    exceptionSets.add(docSetName);
                }
                if (_securityScopeCollection) {
                  // we don't add in any exceptions that have document sets
                  if (!exceptionSets.isEmpty()) {
                    continue;
                  }
                }
                securityException.put("groups", exceptionGroups);
                securityException.put("sets", exceptionSets);
                _securityExceptions.add(securityException);
            }
        }
    }

    protected boolean configureServiceRacks(Element coll_config_xml, Element build_config_xml)
    {
        clearServices();
        Element service_list = (Element) GSXML.getChildByTagName(build_config_xml, GSXML.SERVICE_CLASS_ELEM + GSXML.LIST_MODIFIER);
        if (service_list != null)
        {
            configureServiceRackList(service_list, coll_config_xml);
        }
        // collection Config may also contain manually added service racks
        service_list = (Element) GSXML.getChildByTagName(coll_config_xml, GSXML.SERVICE_CLASS_ELEM + GSXML.LIST_MODIFIER);
        if (service_list != null)
        {
            configureServiceRackList(service_list, build_config_xml);
        }
        return true;
    }

    /**
     * do a configure on only part of the collection
     */
    protected boolean configureSubset(String subset)
    {

        // need the coll config files
        Element coll_config_elem = loadCollConfigFile();
        Element build_config_elem = loadBuildConfigFile();
        if (coll_config_elem == null || build_config_elem == null)
        {
            // wont be able to do any of the requests
            return false;
        }

        if (subset.equals(GSXML.SERVICE_ELEM + GSXML.LIST_MODIFIER))
        {
            return configureServiceRacks(coll_config_elem, build_config_elem);
        }

        if (subset.equals(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER) || subset.equals(GSXML.DISPLAY_TEXT_ELEM + GSXML.LIST_MODIFIER) || subset.equals(GSXML.LIBRARY_PARAM_ELEM+GSXML.LIST_MODIFIER))
        {
            configureLocalData(coll_config_elem);
            configureLocalData(build_config_elem);
            return findAndLoadInfo(coll_config_elem, build_config_elem);

        }

        logger.error("Collection: cant process system request, configure " + subset);
        return false;
    }

    /**
     * handles requests made to the ServiceCluster itself
     * 
     * @param req
     *            - the request Element- <request>
     * @return the result Element - should be <response>
     */
  protected Element processMessage(Document result_doc, Element request)
    {
        String type = request.getAttribute(GSXML.TYPE_ATT);
        if (type.equals(GSXML.REQUEST_TYPE_FORMAT_STRING))
        {
          return processFormatStringRequest(result_doc, request);
        }
        else if (type.equals(GSXML.REQUEST_TYPE_SECURITY))
        {
          return processSecurityRequest(result_doc, request);
        }
        else if (type.equals(GSXML.REQUEST_TYPE_FORMAT))
        {

            Element response = result_doc.createElement(GSXML.RESPONSE_ELEM);
            response.setAttribute(GSXML.FROM_ATT, this.cluster_name);
            response.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_FORMAT);
            if (_globalFormat != null)
            {
                response.appendChild(result_doc.importNode(_globalFormat, true));
            }
            return response;
        }
        // unknown type
        return super.processMessage(result_doc, request);

    }

  protected Element processSecurityRequest(Document result_doc, Element request)
    {
        Element response = result_doc.createElement(GSXML.RESPONSE_ELEM);
        response.setAttribute(GSXML.FROM_ATT, this.cluster_name);
        response.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_SECURITY);

        if (_humanVerify != null) {
          response.setAttribute(GSXML.VERIFY_ATT, _humanVerify);
          if (_useRecaptcha) {
            response.setAttribute(GSXML.SITE_KEY_ATT, _siteKey);
            response.setAttribute(GSXML.SECRET_KEY_ATT, _secretKey);
          }
        }
        String oid = request.getAttribute("oid");
        if (oid.contains("."))
        {
            oid = oid.substring(0, oid.indexOf("."));
        }

        ArrayList<String> groups = getPermittedGroups(oid);

        Element groupList = result_doc.createElement(GSXML.GROUP_ELEM + GSXML.LIST_MODIFIER);
        response.appendChild(groupList);

        for (String groupName : groups)
        {
            Element group = result_doc.createElement(GSXML.GROUP_ELEM);
            groupList.appendChild(group);
            group.setAttribute(GSXML.NAME_ATT, groupName);
        }
        return response;
    }

    protected ArrayList<String> getPermittedGroups(String oid)
    {
        ArrayList<String> groups = new ArrayList<String>();

        if (_securityScopeCollection)
        {
            if (_publicAccess)
            {
                groups.add("");
            }
            else
            {
                for (HashMap<String, ArrayList<String>> exception : _securityExceptions)
                {
                    for (String group : exception.get("groups"))
                    {
                        groups.add(group);
                    }
                }
            }
        }
        else
        {
            if (oid != null && !oid.equals(""))
            {
                boolean inSet = false;
                for (HashMap<String, ArrayList<String>> exception : _securityExceptions) {
                  
                  ArrayList<String> exceptionSets = exception.get("sets");
                   if (exceptionSets.size() == 0) {
                    inSet = true;
                    for (String group : exception.get("groups"))
                      {
                    groups.add(group);
                      }
                   }
                   else {
                      for (String setName : exception.get("sets"))
                    {
                      if (documentIsInSet(oid, setName))
                        {
                          inSet = true;
                          for (String group : exception.get("groups"))
                        {
                          groups.add(group);
                        }
                          break;
                        }
                    }
                   }
                }
            
            
                  
                if (!inSet && _publicAccess)
                  {// our doc was not part of any exception, so it must be public
                    groups.add("");
                }
            }
            else // if we are not doing a request with an oid, then free to access
            {
                groups.add("");
            }
        }

        return groups;
    }

    protected boolean documentIsInSet(String oid, String setName)
    {
        ArrayList<Element> matchStatements = _documentSets.get(setName);
        if (matchStatements == null || matchStatements.size() == 0)
        {
            return false;
        }

        for (Element currentMatchStatement : matchStatements)
        {
            String fieldName = currentMatchStatement.getAttribute(GSXML.FIELD_ATT);
            if (fieldName == null || fieldName.equals(""))
            {
                fieldName = "oid";
            }

            String type = currentMatchStatement.getAttribute(GSXML.TYPE_ATT);
            if (type == null || type.equals(""))
            {
                type = "match";
            }

            //String fieldValue = "";
            String[] fieldValues = null;
            if (!fieldName.equals("oid"))
            {
                //fieldValue = getFieldValue(oid, fieldName);
                fieldValues = getFieldValues(oid, fieldName);
                if (fieldValues == null)
                {
                    return false;
                }
            }
            else
            {
                //fieldValue = oid;
                //fieldValues = new String[0]; 
                //fieldValues[0] = oid;
                fieldValues = new String[]{oid}; // not allowed to do fieldValues = {oid}; after SEPARATE declaration.
            }

            String matchValue = GSXML.getNodeText(currentMatchStatement);
            if (type.equals("match"))
            {

                for(int i = 0; i < fieldValues.length; i++) {
                String fieldValue = fieldValues[i];
                if (matchValue.equals(fieldValue))
                {
                    return true;
                }
                }
            }
            else if (type.equals("regex"))
            {
                for(int i = 0; i < fieldValues.length; i++) {
                String fieldValue = fieldValues[i];
                if (fieldValue.matches(matchValue))
                {
                    return true;
                }
                }
            }
            else
            {
                logger.warn("Unknown type of match specified in security block of collection " + this.cluster_name + ".");
            }
        }

        return false;
    }

    protected String old_getFieldValue(String oid, String fieldName)
    {
      Document msg_doc = XMLConverter.newDOM();
        Element metadataMessage = msg_doc.createElement(GSXML.MESSAGE_ELEM);
        Element metadataRequest = GSXML.createBasicRequest(msg_doc, GSXML.REQUEST_TYPE_PROCESS, this.cluster_name + "/DocumentMetadataRetrieve", new UserContext());
        metadataMessage.appendChild(metadataRequest);

        Element paramList = msg_doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        metadataRequest.appendChild(paramList);

        Element param = msg_doc.createElement(GSXML.PARAM_ELEM);
        paramList.appendChild(param);

        param.setAttribute(GSXML.NAME_ATT, "metadata");
        param.setAttribute(GSXML.VALUE_ATT, fieldName);

        Element docList = msg_doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
        metadataRequest.appendChild(docList);

        Element doc = msg_doc.createElement(GSXML.DOC_NODE_ELEM);
        docList.appendChild(doc);

        doc.setAttribute(GSXML.NODE_ID_ATT, oid);

        Element response = (Element) this.router.process(metadataMessage);
        NodeList metadataElems = response.getElementsByTagName(GSXML.METADATA_ELEM);

        if (metadataElems.getLength() > 0)
        {
            Element metadata = (Element) metadataElems.item(0);
            return GSXML.getNodeText(metadata);
        }

        return null;
    }

    protected String[] getFieldValues(String oid, String fieldName)
    {
      Document msg_doc = XMLConverter.newDOM();
        Element metadataMessage = msg_doc.createElement(GSXML.MESSAGE_ELEM);
        Element metadataRequest = GSXML.createBasicRequest(msg_doc, GSXML.REQUEST_TYPE_PROCESS, this.cluster_name + "/DocumentMetadataRetrieve", new UserContext());
        metadataMessage.appendChild(metadataRequest);

        Element paramList = msg_doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        metadataRequest.appendChild(paramList);

        Element param = msg_doc.createElement(GSXML.PARAM_ELEM);
        paramList.appendChild(param);

        param.setAttribute(GSXML.NAME_ATT, "metadata");
        param.setAttribute(GSXML.VALUE_ATT, fieldName);

        Element docList = msg_doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
        metadataRequest.appendChild(docList);

        Element doc = msg_doc.createElement(GSXML.DOC_NODE_ELEM);
        docList.appendChild(doc);

        doc.setAttribute(GSXML.NODE_ID_ATT, oid);

        Element response = (Element) this.router.process(metadataMessage);
        NodeList metadataElems = response.getElementsByTagName(GSXML.METADATA_ELEM);

        if (metadataElems.getLength() <= 0) {
            return null;
        }
        // else
        String[] fieldValues = new String[metadataElems.getLength()];
        for(int i = 0; i < metadataElems.getLength(); i++)
        {
            Element metadata = (Element) metadataElems.item(i);
            fieldValues[i] = GSXML.getNodeText(metadata);
        }

        return fieldValues;

    }

  protected Element processFormatStringRequest(Document result_doc, Element request)
    {
        Element response = result_doc.createElement(GSXML.RESPONSE_ELEM);
        response.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_FORMAT_STRING);
        response.setAttribute(GSXML.FROM_ATT, this.cluster_name);

        String subaction = request.getAttribute("subaction");
        String service = request.getAttribute("service");

        String classifier = null;
        if (service.equals("ClassifierBrowse"))
        {
            classifier = request.getAttribute("classifier");
        }

        // check for version file
        String directory = new File(GSFile.collectionConfigFile(this.site_home, this.cluster_name)).getParent() + File.separator;

        String version_filename = "";
        if (service.equals("ClassifierBrowse"))
            version_filename = directory + "browse_" + classifier + "_format_statement_version.txt";
        else
            version_filename = directory + "query_format_statement_version.txt";

        File version_file = new File(version_filename);

        if (subaction.equals("update"))
        {
            Element format_element = (Element) GSXML.getChildByTagName(request, GSXML.FORMAT_STRING_ELEM);
            //String format_string = GSXML.getNodeText(format_element);
            Element format_statement = (Element) format_element.getFirstChild();

            String version_number = "1";
            BufferedWriter writer;

            try
            {

                if (version_file.exists())
                {
                    // Read version
                    BufferedReader reader = new BufferedReader(new FileReader(version_filename));
                    version_number = reader.readLine();
                    int aInt = Integer.parseInt(version_number) + 1;
                    version_number = Integer.toString(aInt);
                    reader.close();
                }
                else
                {
                    // Create
                    version_file.createNewFile();
                    writer = new BufferedWriter(new FileWriter(version_filename));
                    writer.write(version_number);
                    writer.close();
                }

                // Write version file
                String format_statement_filename = "";

                if (service.equals("ClassifierBrowse"))
                    format_statement_filename = directory + "browse_" + classifier + "_format_statement_v" + version_number + ".txt";
                else
                    format_statement_filename = directory + "query_format_statement_v" + version_number + ".txt";

                // Write format statement
                String format_string = this.converter.getString(format_statement); //GSXML.xmlNodeToString(format_statement);
                writer = new BufferedWriter(new FileWriter(format_statement_filename));
                writer.write(format_string);
                writer.close();

                // Update version number
                writer = new BufferedWriter(new FileWriter(version_filename));
                writer.write(version_number);
                writer.close();

            }
            catch (IOException e)
            {
                logger.error("IO Exception " + e);
            }
        }

        if (subaction.equals("saveDocument"))
        {
            Element format_element = (Element) GSXML.getChildByTagName(request, GSXML.FORMAT_STRING_ELEM);
            //String format_string = GSXML.getNodeText(format_element);
            // Get display tag
            Element display_format = (Element) format_element.getFirstChild();

            String collection_config = directory + "collectionConfig.xml";
            Document config = this.converter.getDOM(new File(collection_config), "UTF-8");

            Node current_node = GSXML.getChildByTagName(config, "CollectionConfig");

            // Get display child
            if (GSXML.getChildByTagName(current_node, "display") == null)
            {
                // well then create a format tag
                Element display_tag = config.createElement("display");
                current_node = (Node) current_node.appendChild(display_tag);
            }
            else
            {
                current_node = GSXML.getChildByTagName(current_node, "display");
            }

            if (GSXML.getChildByTagName(current_node, "format") == null)
            {
                // well then create a format tag
                Element format_tag = config.createElement("format");
                current_node.appendChild(format_tag);
            }

            current_node.replaceChild(config.importNode(display_format, true), GSXML.getChildByTagName(current_node, "format"));

            String new_config = this.converter.getString(config);

            new_config = StringUtils.replace(new_config, "&lt;", "<");
            new_config = StringUtils.replace(new_config, "&gt;", ">");
            new_config = StringUtils.replace(new_config, "&quot;", "\"");

            try
            {
                // Write to file (not original! for now)
                BufferedWriter writer = new BufferedWriter(new FileWriter(collection_config + ".new"));
                writer.write(new_config);
                writer.close();
            }
            catch (IOException e)
            {
                logger.error("IO Exception " + e);
            }
        }

        if (subaction.equals("save"))
        {
            Element format_element = (Element) GSXML.getChildByTagName(request, GSXML.FORMAT_STRING_ELEM);
            Element format_statement = (Element) format_element.getFirstChild();

            try
            {
                // open collectionConfig.xml and read in to w3 Document
                String collection_config = directory + "collectionConfig.xml";
                Document config = this.converter.getDOM(new File(collection_config), "UTF-8");

                //String tag_name = "";
                int k;
                int index;
                Element elem;
                Node current_node = GSXML.getChildByTagName(config, "CollectionConfig");
                NodeList current_node_list;

                if (service.equals("ClassifierBrowse"))
                {
                    //tag_name = "browse";
                    // if CLX then need to look in <classifier> X then <format>
                    // default is <browse><format>

                    current_node = GSXML.getChildByTagName(current_node, "browse");

                    // find CLX
                    if (classifier != null)
                    {
                        current_node_list = GSXML.getChildrenByTagName(current_node, "classifier");
                        index = Integer.parseInt(classifier.substring(2)) - 1;

                        // index should be given by X-1
                        current_node = current_node_list.item(index);
                        // what if classifier does not have a format tag?
                        if (GSXML.getChildByTagName(current_node, "format") == null)
                        {
                            // well then create a format tag
                            Element format_tag = config.createElement("format");
                            current_node.appendChild(format_tag);
                        }
                    }
                    else
                    {
                        // To support all classifiers, set classifier to null?  There is the chance here that the format tag does not exist
                        if (GSXML.getChildByTagName(current_node, "format") == null)
                        {
                            // well then create a format tag
                            Element format_tag = config.createElement("format");
                            current_node.appendChild(format_tag);
                        }
                    }
                }
                else if (service.equals("AllClassifierBrowse"))
                {
                    current_node = GSXML.getChildByTagName(current_node, "browse");
                    if (GSXML.getChildByTagName(current_node, "format") == null)
                    {
                        // well then create a format tag
                        Element format_tag = config.createElement("format");
                        current_node.appendChild(format_tag);
                    }
                }
                else
                {
                    // look in <format> with no attributes
                    current_node_list = GSXML.getChildrenByTagName(current_node, "search");
                    for (k = 0; k < current_node_list.getLength(); k++)
                    {
                        current_node = current_node_list.item(k);
                        // if current_node has no attributes then break
                        elem = (Element) current_node;
                        if (elem.hasAttribute("name") == false)
                            break;
                    }
                }

                current_node.replaceChild(config.importNode(format_statement, true), GSXML.getChildByTagName(current_node, "format"));

                // Now convert config document to string for writing to file
                String new_config = this.converter.getString(config);

                new_config = StringUtils.replace(new_config, "&lt;", "<");
                new_config = StringUtils.replace(new_config, "&gt;", ">");
                new_config = StringUtils.replace(new_config, "&quot;", "\"");

                // Write to file (not original! for now)
                BufferedWriter writer = new BufferedWriter(new FileWriter(collection_config + ".new"));
                writer.write(new_config);
                writer.close();

            }
            catch (Exception ex)
            {
                logger.error("There was an exception " + ex);

                StringWriter sw = new StringWriter();
                PrintWriter pw = new PrintWriter(sw, true);
                ex.printStackTrace(pw);
                pw.flush();
                sw.flush();
                logger.error(sw.toString());
            }

        }

        return response;
    }


}