Java tutorial
package com.zghw.lucene.demo; /* * 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. */ import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.lucene.analysis.core.WhitespaceAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.facet.DrillDownQuery; import org.apache.lucene.facet.FacetResult; import org.apache.lucene.facet.Facets; import org.apache.lucene.facet.FacetsCollector; import org.apache.lucene.facet.FacetsConfig; import org.apache.lucene.facet.taxonomy.FloatAssociationFacetField; import org.apache.lucene.facet.taxonomy.IntAssociationFacetField; import org.apache.lucene.facet.taxonomy.TaxonomyFacetSumFloatAssociations; import org.apache.lucene.facet.taxonomy.TaxonomyFacetSumIntAssociations; import org.apache.lucene.facet.taxonomy.TaxonomyReader; import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyReader; import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter; import org.apache.lucene.index.DirectoryReader; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.MatchAllDocsQuery; import org.apache.lucene.store.Directory; import org.apache.lucene.store.RAMDirectory; /** Shows example usage of category associations. */ public class AssociationsFacetsExample { private final Directory indexDir = new RAMDirectory(); private final Directory taxoDir = new RAMDirectory(); private final FacetsConfig config; /** Empty constructor */ public AssociationsFacetsExample() { config = new FacetsConfig(); config.setMultiValued("tags", true); config.setIndexFieldName("tags", "$tags"); config.setMultiValued("genre", true); config.setIndexFieldName("genre", "$genre"); } /** Build the example index. */ private void index() throws IOException { IndexWriterConfig iwc = new IndexWriterConfig(FacetExamples.EXAMPLES_VER, new WhitespaceAnalyzer()); IndexWriter indexWriter = new IndexWriter(indexDir, iwc); // Writes facet ords to a separate directory from the main index DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir); Document doc = new Document(); // 3 occurrences for tag 'lucene' doc.add(new IntAssociationFacetField(3, "tags", "lucene")); // 87% confidence level of genre 'computing' doc.add(new FloatAssociationFacetField(0.87f, "genre", "computing")); indexWriter.addDocument(config.build(taxoWriter, doc)); doc = new Document(); // 1 occurrence for tag 'lucene' doc.add(new IntAssociationFacetField(1, "tags", "lucene")); // 2 occurrence for tag 'solr' doc.add(new IntAssociationFacetField(2, "tags", "solr")); // 75% confidence level of genre 'computing' doc.add(new FloatAssociationFacetField(0.75f, "genre", "computing")); // 34% confidence level of genre 'software' doc.add(new FloatAssociationFacetField(0.34f, "genre", "software")); indexWriter.addDocument(config.build(taxoWriter, doc)); indexWriter.close(); taxoWriter.close(); } /** User runs a query and aggregates facets by summing their association values. */ private List<FacetResult> sumAssociations() throws IOException { DirectoryReader indexReader = DirectoryReader.open(indexDir); IndexSearcher searcher = new IndexSearcher(indexReader); TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir); FacetsCollector fc = new FacetsCollector(); // MatchAllDocsQuery is for "browsing" (counts facets // for all non-deleted docs in the index); normally // you'd use a "normal" query: FacetsCollector.search(searcher, new MatchAllDocsQuery(), 10, fc); Facets tags = new TaxonomyFacetSumIntAssociations("$tags", taxoReader, config, fc); Facets genre = new TaxonomyFacetSumFloatAssociations("$genre", taxoReader, config, fc); // Retrieve results List<FacetResult> results = new ArrayList<FacetResult>(); results.add(tags.getTopChildren(10, "tags")); results.add(genre.getTopChildren(10, "genre")); indexReader.close(); taxoReader.close(); return results; } /** User drills down on 'tags/solr'. */ private FacetResult drillDown() throws IOException { DirectoryReader indexReader = DirectoryReader.open(indexDir); IndexSearcher searcher = new IndexSearcher(indexReader); TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir); // Passing no baseQuery means we drill down on all // documents ("browse only"): DrillDownQuery q = new DrillDownQuery(config); // Now user drills down on Publish Date/2010: q.add("tags", "solr"); FacetsCollector fc = new FacetsCollector(); FacetsCollector.search(searcher, q, 10, fc); // Retrieve results Facets facets = new TaxonomyFacetSumFloatAssociations("$genre", taxoReader, config, fc); FacetResult result = facets.getTopChildren(10, "genre"); indexReader.close(); taxoReader.close(); return result; } /** Runs summing association example. */ public List<FacetResult> runSumAssociations() throws IOException { index(); return sumAssociations(); } /** Runs the drill-down example. */ public FacetResult runDrillDown() throws IOException { index(); return drillDown(); } /** Runs the sum int/float associations examples and prints the results. */ public static void main(String[] args) throws Exception { System.out.println("Sum associations example:"); System.out.println("-------------------------"); List<FacetResult> results = new AssociationsFacetsExample().runSumAssociations(); System.out.println("tags: " + results.get(0)); System.out.println("genre: " + results.get(1)); } }