keywordssearcher.java

联合国农粮署牵头开发的geonetwork源代码最新版

//===	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.search;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;

import jeeves.server.context.ServiceContext;
import jeeves.utils.Util;

import org.fao.geonet.kernel.Thesaurus;
import org.fao.geonet.kernel.ThesaurusManager;
import org.fao.geonet.kernel.KeywordBean;
import org.jdom.Element;
import org.openrdf.model.Value;
import org.openrdf.sesame.query.QueryResultsTable;

public class KeywordsSearcher {
	private ThesaurusManager _tm;

	private String _query;
	private String _lang;
	private String _sortBy = "label";
	private String _sortOrder = "ascending";

	private ArrayList<KeywordBean> _results = new ArrayList<KeywordBean>();

	private int _pTypeSearch = 1;


	// --------------------------------------------------------------------------------
	// constructor
	public KeywordsSearcher(ThesaurusManager tm) {
		_tm = tm;
	}

	// --------------------------------------------------------------------------------
	public KeywordBean searchById(String id, String sThesaurusName, String lang)
	throws Exception {

		_query = "SELECT prefLab, note, id, lowc, uppc "
			+ " FROM {id} rdf:type {skos:Concept}; "
			+ " skos:prefLabel {prefLab};"
			+ " [skos:scopeNote {note} WHERE lang(note) LIKE \""+lang+"\"]; "
			+ " [gml:BoundedBy {} gml:lowerCorner {lowc}]; "
			+ " [gml:BoundedBy {} gml:upperCorner {uppc}] "
			+ " WHERE lang(prefLab) LIKE \""+lang+"\" "
			+ " AND id LIKE \""+id+"\" "
			+ " IGNORE CASE "
			+ " USING NAMESPACE skos=<http://www.w3.org/2004/02/skos/core#>, gml=<http://www.opengis.net/gml#> ";

			Thesaurus thesaurus = _tm.getThesaurusByName(sThesaurusName);

			// Perform request
			QueryResultsTable resultsTable = thesaurus.performRequest(_query);
			int rowCount = resultsTable.getRowCount();
			int idKeyword = 0;

			if (rowCount == 0){
				return null;
			}else{
				// MUST be one because search by ID

				// preflab
				Value value = resultsTable.getValue(0, 0);
				String sValue = "";
				if (value != null) {
					sValue = value.toString();
				}

//				 uri (= id in RDF file != id in list)
				Value uri = resultsTable.getValue(0, 2);
				String sUri = "";
				if (uri != null) {
					sUri = uri.toString();
				}

				KeywordBean kb = new KeywordBean(idKeyword, sValue,
						"", sUri, "", "", "", "",
						sThesaurusName, false, _lang);
				idKeyword++;

				return kb;
			}

	}

	public void search(ServiceContext srvContext, Element params)
			throws Exception {
		// Get params from request and set default
		String sKeyword = Util.getParam(params, "pKeyword");


		// Type of search
		int pTypeSearch = _pTypeSearch;
		if (params.getChild("pTypeSearch") != null){							// if param pTypeSearch not here
			pTypeSearch = Util.getParamAsInt(params, "pTypeSearch");

		// Thesaurus to search in
		List listThesauri = new Vector<Element>();
		// Type of thesaurus to search in
		String pTypeThesaurus = null;
		if (params.getChild("pType") != null)							// if param pTypeSearch not here
			pTypeThesaurus = Util.getParam(params, "pType");

		boolean bAll = true;

		if (params.getChild("pThesauri") != null){							// if param pThesauri not here
			listThesauri = params.getChildren("pThesauri");
			bAll = false;

			if (((Element) listThesauri.get(0)).getTextTrim().equals(""))	// If first element is empty </>
				bAll = true;
		}

		//	If no thesaurus search in all.
		if (bAll){
			Hashtable<String, Thesaurus> tt = _tm.getThesauriTable();

			Enumeration e = tt.keys();
			boolean add = true;
		    while (e.hasMoreElements())										// Fill the list with all thesauri available
		    {
		    	Thesaurus thesaurus = tt.get(e.nextElement());
		    	if (pTypeThesaurus != null){
			    	if (!thesaurus.getDname().equals(pTypeThesaurus)) // Add thesaurus only if type is corresponding with MD type (based on ISO type ie. theme, discipline, ...)
			    		add = false;
			    	else
			    		add = true;
		    	}

		    	if (add){
		    		Element el = new Element("pThesauri");
			    	el.addContent(thesaurus.getKey());
			    	listThesauri.add(el);
		    	}
		    }
		}


		// Keyword to look for
		if (!sKeyword.equals("")) {

			// FIXME : Where to search ? only on term having GUI language or in all ?
			// Should be
			// - look for a term in all language
			// - get prefLab in GUI lang
			// This will cause multilingual metadata search quite complex !!
			// Quid Lucene and thesaurus ?

			String _lang = srvContext.getLanguage();
			_query = "SELECT prefLab, note, id, lowc, uppc "
				+ " FROM {id} rdf:type {skos:Concept}; "
				+ " skos:prefLabel {prefLab};"
				+ " [skos:scopeNote {note} WHERE lang(note) LIKE \""+_lang+"\"]; "
				+ " [gml:BoundedBy {} gml:lowerCorner {lowc}]; "
				+ " [gml:BoundedBy {} gml:upperCorner {uppc}] "
				+ " WHERE lang(prefLab) LIKE \""+_lang+"\""
				+ " AND prefLab LIKE ";

			switch (pTypeSearch) {
			case 0: // commence par
				_query += "\""+ sKeyword+ "*\" ";
				break;
			case 1: // contient
				_query += "\"*"+ sKeyword+ "*\" ";
				break;
			case 2: // terme exact
				_query += "\""+ sKeyword+ "\" ";
				break;
			default:
				break;
			}
			_query 	+= " IGNORE CASE "
					+ " USING NAMESPACE skos=<http://www.w3.org/2004/02/skos/core#>, gml=<http://www.opengis.net/gml#> ";

		}


		// For each thesaurus, search for keywords in _results
		_results = new ArrayList<KeywordBean>();
		int idKeyword = 0;

		for (int i = 0; i < listThesauri.size(); i++) { 			// Search in all Thesaurus if none selected
			Element el = (Element) listThesauri.get(i);
			String sThesaurusName = el.getTextTrim();

			Thesaurus thesaurus = _tm.getThesaurusByName(sThesaurusName);

			// Perform request
			QueryResultsTable resultsTable = thesaurus.performRequest(_query);

			int rowCount = resultsTable.getRowCount();

			for (int row = 0; row < rowCount; row++) {
				// preflab
				Value value = resultsTable.getValue(row, 0);
				String sValue = "";
				if (value != null) {
					sValue = value.toString();
				}
				// definition
				Value definition = resultsTable.getValue(row, 1);
				String sDefinition = "";
				if (definition != null) {
					sDefinition = definition.toString();
				}
				// uri (= id in RDF file != id in list)
				Value uri = resultsTable.getValue(row, 2);
				String sUri = "";
				if (uri != null) {
					sUri = uri.toString();
				}
				// lowcorner
				Value lowCorner = resultsTable.getValue(row, 4);
				String sLowCorner = "";
				String sEast = "";
				String sSouth = "";
				if (lowCorner != null) {
					sLowCorner = lowCorner.toString();
					sEast = sLowCorner.substring(0, sLowCorner.indexOf(' '))
							.trim();