searchcontroller.java

由国外的一个著名的geonetwork修改而来

//=============================================================================
//===	Copyright (C) 2001-2005 Food and Agriculture Organization of the
//===	United Nations (FAO-UN), United Nations World Food Programme (WFP)
//===	and United Nations Environment Programme (UNEP)
//===
//===	This program is free software; you can redistribute it and/or modify
//===	it under the terms of the GNU General Public License as published by
//===	the Free Software Foundation; either version 2 of the License, or (at
//===	your option) any later version.
//===
//===	This program is distributed in the hope that it will be useful, but
//===	WITHOUT ANY WARRANTY; without even the implied warranty of
//===	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//===	General Public License for more details.
//===
//===	You should have received a copy of the GNU General Public License
//===	along with this program; if not, write to the Free Software
//===	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//===
//===	Contact: Jeroen Ticheler - FAO - Viale delle Terme di Caracalla 2,
//===	Rome - Italy. email: [e-mail]
//==============================================================================

package org.fao.geonet.kernel.csw.services.getrecords;

import java.io.File;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import jeeves.resources.dbms.Dbms;
import jeeves.server.context.ServiceContext;
import jeeves.utils.Util;
import jeeves.utils.Xml;
import org.fao.geonet.constants.Geonet;
import org.fao.geonet.csw.common.Csw;
import org.fao.geonet.csw.common.Csw.ElementSetName;
import org.fao.geonet.csw.common.Csw.OutputSchema;
import org.fao.geonet.csw.common.Csw.ResultType;
import org.fao.geonet.csw.common.Csw.TypeName;
import org.fao.geonet.csw.common.exceptions.CatalogException;
import org.fao.geonet.csw.common.exceptions.NoApplicableCodeEx;
import org.jdom.Element;

//=============================================================================

public class SearchController
{
	//---------------------------------------------------------------------------
	//---
	//--- Single public method to perform the general search tasks
	//---
	//---------------------------------------------------------------------------

	public Element search(ServiceContext context, int startPos, int maxRecords, int hopCount,
								 ResultType resultType, OutputSchema outSchema, ElementSetName setName,
								 Set<TypeName> typeNames, Element filterExpr, List<SortField> sortFields)
									throws CatalogException
	{
		Element results = new Element("SearchResults", Csw.NAMESPACE_CSW);

		CatalogSearcher searcher = new CatalogSearcher();

		List<ResultItem> searchResults = searcher.search(context, filterExpr, typeNames, sortFields);

		int counter = 0;

		if (resultType == ResultType.RESULTS)
			for (int i=startPos; (i<startPos+maxRecords) && (i<=searchResults.size()); i++)
			{
				counter++;

				String  id = searchResults.get(i -1).getID();
				Element md = retrieveMetadata(context, id, setName, outSchema);

				if (md == null)
					context.warning("SearchController : Metadata not found or invalid schema : "+ id);
				else
					results.addContent(md);
			}

		results.setAttribute("numberOfRecordsMatched",  searchResults.size() +"");
		results.setAttribute("numberOfRecordsReturned", counter +"");
		results.setAttribute("elementSet",              setName.toString());

		return results;
	}

	//---------------------------------------------------------------------------

	private Element retrieveMetadata(ServiceContext context, String id, ElementSetName setName, OutputSchema outSchema) throws CatalogException
	{
		try
		{
			Dbms dbms = (Dbms) context.getResourceManager().open(Geonet.Res.MAIN_DB);

			//--- get metadata from DB

			Element  res = dbms.select("SELECT schemaId, data FROM Metadata WHERE id="+id);
			Iterator i   = res.getChildren().iterator();

			dbms.commit();

			if (!i.hasNext())
				return null;

			Element record = (Element) i.next();

			String schema = record.getChildText("schemaid");
			String data   = record.getChildText("data");

			//--- skip metadata with wrong schemas

			if (schema.equals("fgdc-std") || schema.equals("dublin-core") || schema.equals("iso19115"))
				if (outSchema != OutputSchema.OGC_CORE)
					return null;

			Element md = Xml.loadString(data, false);

			//--- apply stylesheet according to setName and schema

			String FS         = File.separator;
			String schemaDir  = context.getAppPath() +"xml"+ FS +"csw"+ FS +"schemas"+ FS +schema+ FS;
			String prefix     = (outSchema == OutputSchema.OGC_CORE) ? "ogc" : "iso";
			String styleSheet = schemaDir + prefix +"-"+ setName +".xsl";

			md = Xml.transform(md, styleSheet);

			//--- needed to detach md from the document
			md.detach();

			return md;
		}
		catch (Exception e)
		{
			context.error("Error while getting metadata with id : "+ id);
			context.error("  (C) StackTrace:\n"+ Util.getStackTrace(e));

			throw new NoApplicableCodeEx("Rised exception while getting metadata :"+ e);
		}
	}
}

//=============================================================================