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/* Derby - Class org.apache.derby.optional.api.LuceneUtils Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package org.apache.derby.optional.api; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.sql.SQLException; import java.util.HashMap; import java.util.Locale; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.queryparser.classic.MultiFieldQueryParser; import org.apache.lucene.queryparser.classic.QueryParser; import org.apache.lucene.util.Version; import org.apache.derby.iapi.error.PublicAPI; import org.apache.derby.iapi.error.StandardException; import org.apache.derby.iapi.sql.conn.ConnectionUtil; import org.apache.derby.iapi.sql.conn.LanguageConnectionContext; /** * <p> * Utility methods for the Lucene optional tool. * </p> */ public abstract class LuceneUtils { ///////////////////////////////////////////////////////////////// // // CONSTANTS // ///////////////////////////////////////////////////////////////// public static final String TEXT_FIELD_NAME = "luceneTextField"; ///////////////////////////////////////////////////////////////// // // STATE // ///////////////////////////////////////////////////////////////// /** Map of Analyzers keyed by language code */ private static HashMap<String, Class<? extends Analyzer>> _analyzerClasses; static { _analyzerClasses = new HashMap<String, Class<? extends Analyzer>>(); storeAnalyzerClass(org.apache.lucene.analysis.ar.ArabicAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.hy.ArmenianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.eu.BasqueAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.br.BrazilianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.bg.BulgarianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.ca.CatalanAnalyzer.class); // deprecated, use StandardAnalyzer instead: storeAnalyzerClass( org.apache.lucene.analysis.cn.ChineseAnalyzer.class ); storeAnalyzerClass(org.apache.lucene.analysis.cz.CzechAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.da.DanishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.nl.DutchAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.en.EnglishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.fi.FinnishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.fr.FrenchAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.gl.GalicianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.de.GermanAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.el.GreekAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.hi.HindiAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.hu.HungarianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.id.IndonesianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.ga.IrishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.it.ItalianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.lv.LatvianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.no.NorwegianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.fa.PersianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.pt.PortugueseAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.ro.RomanianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.ru.RussianAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.es.SpanishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.sv.SwedishAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.th.ThaiAnalyzer.class); storeAnalyzerClass(org.apache.lucene.analysis.tr.TurkishAnalyzer.class); } ///////////////////////////////////////////////////////////////// // // PUBLIC BEHAVIOR // ///////////////////////////////////////////////////////////////// /** Get the version of the Lucene library on the classpath. */ @SuppressWarnings("deprecation") public static Version currentVersion() { Version retval = null; // the current version is the highest one for (Version current : Version.values()) { if (current == Version.LUCENE_CURRENT) { continue; } if (retval == null) { retval = current; } else { if (current.onOrAfter(retval)) { retval = current; } } } return retval; } /** * <p> * Get the default Analyzer associated with the database Locale. * </p> */ public static Analyzer defaultAnalyzer() throws SQLException { return getAnalyzerForLocale(ConnectionUtil.getCurrentLCC().getDatabase().getLocale()); } /** * <p> * Get the Analyzer associated with the given Locale. * </p> */ public static Analyzer getAnalyzerForLocale(Locale locale) throws SQLException { String language = locale.getLanguage(); try { Class<? extends Analyzer> analyzerClass = _analyzerClasses.get(language); if (analyzerClass == null) { return standardAnalyzer(); } else { Constructor<? extends Analyzer> constructor = analyzerClass.getConstructor(Version.class); return constructor.newInstance(currentVersion()); } } catch (IllegalAccessException iae) { throw wrap(iae); } catch (InstantiationException ie) { throw wrap(ie); } catch (InvocationTargetException ite) { throw wrap(ite); } catch (NoSuchMethodException nsme) { throw wrap(nsme); } } /** * <p> * Get the StandardAnalyzer for parsing text. * </p> */ public static Analyzer standardAnalyzer() { return new StandardAnalyzer(currentVersion()); } /** * <p> * Get the default, classic QueryParser. * </p> */ public static QueryParser defaultQueryParser(Version version, String[] fieldNames, Analyzer analyzer) { return new MultiFieldQueryParser(version, fieldNames, analyzer); } /** * <p> * Get the default index descriptor. This has a single field named TEXT, * a defaultAnalyzer() and a defaultQueryParser(). * </p> */ public static LuceneIndexDescriptor defaultIndexDescriptor() { return new DefaultIndexDescriptor(); } ///////////////////////////////////////////////////////////////// // // MINIONS // ///////////////////////////////////////////////////////////////// /** Store an Analyzer class in the HashMap of Analyzers, keyed by language code */ private static void storeAnalyzerClass(Class<? extends Analyzer> analyzerClass) { _analyzerClasses.put(getLanguageCode(analyzerClass), analyzerClass); } /** * <p> * Get the language code for a Lucene Analyzer. Each of the Analyzers * lives in a package whose last leg is the language code. * </p> */ private static String getLanguageCode(Class<? extends Analyzer> analyzerClass) { String className = analyzerClass.getName(); String packageName = className.substring(0, className.lastIndexOf(".")); String languageCode = packageName.substring(packageName.lastIndexOf(".") + 1, packageName.length()); return languageCode; } /** Wrap an external exception */ private static SQLException wrap(Throwable t) { return sqlException(StandardException.plainWrapException(t)); } /** Turn a StandardException into a SQLException */ private static SQLException sqlException(StandardException se) { return PublicAPI.wrapStandardException(se); } ///////////////////////////////////////////////////////////////// // // NESTED CLASSES // ///////////////////////////////////////////////////////////////// /** The default LuceneIndexDescriptor */ public static class DefaultIndexDescriptor implements LuceneIndexDescriptor { public DefaultIndexDescriptor() { } /** Return the default array of field names { TEXT_FIELD_NAME }. */ public String[] getFieldNames() { return new String[] { TEXT_FIELD_NAME }; } /** Return LuceneUtils.defaultAnalyzer() */ public Analyzer getAnalyzer() throws SQLException { return LuceneUtils.defaultAnalyzer(); } /** * Return LuceneUtils.defaultQueryParser( LuceneUtils.currentVersion(), getFieldNames(), getAnalyzer() ). */ public QueryParser getQueryParser() throws SQLException { return LuceneUtils.defaultQueryParser(LuceneUtils.currentVersion(), getFieldNames(), getAnalyzer()); } } }