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.sortedset.DefaultSortedSetDocValuesReaderState; import org.apache.lucene.facet.sortedset.SortedSetDocValuesFacetCounts; import org.apache.lucene.facet.sortedset.SortedSetDocValuesFacetField; import org.apache.lucene.facet.sortedset.SortedSetDocValuesReaderState; 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 simple usage of faceted indexing and search, * using {@link SortedSetDocValuesFacetField} and {@link * SortedSetDocValuesFacetCounts}. */ public class SimpleSortedSetFacetsExample { private final Directory indexDir = new RAMDirectory(); private final FacetsConfig config = new FacetsConfig(); /** Empty constructor */ public SimpleSortedSetFacetsExample() { } /** Build the example index. */ private void index() throws IOException { IndexWriter indexWriter = new IndexWriter(indexDir, new IndexWriterConfig(FacetExamples.EXAMPLES_VER, new WhitespaceAnalyzer())); Document doc = new Document(); doc.add(new SortedSetDocValuesFacetField("Author", "Bob")); doc.add(new SortedSetDocValuesFacetField("Publish Year", "2010")); indexWriter.addDocument(config.build(doc)); doc = new Document(); doc.add(new SortedSetDocValuesFacetField("Author", "Lisa")); doc.add(new SortedSetDocValuesFacetField("Publish Year", "2010")); indexWriter.addDocument(config.build(doc)); doc = new Document(); doc.add(new SortedSetDocValuesFacetField("Author", "Lisa")); doc.add(new SortedSetDocValuesFacetField("Publish Year", "2012")); indexWriter.addDocument(config.build(doc)); doc = new Document(); doc.add(new SortedSetDocValuesFacetField("Author", "Susan")); doc.add(new SortedSetDocValuesFacetField("Publish Year", "2012")); indexWriter.addDocument(config.build(doc)); doc = new Document(); doc.add(new SortedSetDocValuesFacetField("Author", "Frank")); doc.add(new SortedSetDocValuesFacetField("Publish Year", "1999")); indexWriter.addDocument(config.build(doc)); indexWriter.close(); } /** User runs a query and counts facets. */ private List<FacetResult> search() throws IOException { DirectoryReader indexReader = DirectoryReader.open(indexDir); IndexSearcher searcher = new IndexSearcher(indexReader); SortedSetDocValuesReaderState state = new DefaultSortedSetDocValuesReaderState(indexReader); // Aggregatses the facet counts 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); // Retrieve results Facets facets = new SortedSetDocValuesFacetCounts(state, fc); List<FacetResult> results = new ArrayList<FacetResult>(); results.add(facets.getTopChildren(10, "Author")); results.add(facets.getTopChildren(10, "Publish Year")); indexReader.close(); return results; } /** User drills down on 'Publish Year/2010'. */ private FacetResult drillDown() throws IOException { DirectoryReader indexReader = DirectoryReader.open(indexDir); IndexSearcher searcher = new IndexSearcher(indexReader); SortedSetDocValuesReaderState state = new DefaultSortedSetDocValuesReaderState(indexReader); // Now user drills down on Publish Year/2010: DrillDownQuery q = new DrillDownQuery(config); q.add("Publish Year", "2010"); FacetsCollector fc = new FacetsCollector(); FacetsCollector.search(searcher, q, 10, fc); // Retrieve results Facets facets = new SortedSetDocValuesFacetCounts(state, fc); FacetResult result = facets.getTopChildren(10, "Author"); indexReader.close(); return result; } /** Runs the search example. */ public List<FacetResult> runSearch() throws IOException { index(); return search(); } /** Runs the drill-down example. */ public FacetResult runDrillDown() throws IOException { index(); return drillDown(); } /** Runs the search and drill-down examples and prints the results. */ public static void main(String[] args) throws Exception { System.out.println("Facet counting example:"); System.out.println("-----------------------"); SimpleSortedSetFacetsExample example = new SimpleSortedSetFacetsExample(); List<FacetResult> results = example.runSearch(); System.out.println("Author: " + results.get(0)); System.out.println("Publish Year: " + results.get(0)); System.out.println("\n"); System.out.println("Facet drill-down example (Publish Year/2010):"); System.out.println("---------------------------------------------"); System.out.println("Author: " + example.runDrillDown()); } }