001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.lucene.demo.facet; 018 019import java.io.IOException; 020import java.text.ParseException; 021import org.apache.lucene.analysis.core.WhitespaceAnalyzer; 022import org.apache.lucene.document.Document; 023import org.apache.lucene.document.Field.Store; 024import org.apache.lucene.document.NumericDocValuesField; 025import org.apache.lucene.document.TextField; 026import org.apache.lucene.expressions.Expression; 027import org.apache.lucene.expressions.SimpleBindings; 028import org.apache.lucene.expressions.js.JavascriptCompiler; 029import org.apache.lucene.facet.FacetField; 030import org.apache.lucene.facet.FacetResult; 031import org.apache.lucene.facet.Facets; 032import org.apache.lucene.facet.FacetsCollector; 033import org.apache.lucene.facet.FacetsConfig; 034import org.apache.lucene.facet.taxonomy.TaxonomyFacetSumValueSource; 035import org.apache.lucene.facet.taxonomy.TaxonomyReader; 036import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyReader; 037import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter; 038import org.apache.lucene.index.DirectoryReader; 039import org.apache.lucene.index.IndexWriter; 040import org.apache.lucene.index.IndexWriterConfig; 041import org.apache.lucene.index.IndexWriterConfig.OpenMode; 042import org.apache.lucene.search.DoubleValuesSource; 043import org.apache.lucene.search.IndexSearcher; 044import org.apache.lucene.search.MatchAllDocsQuery; 045import org.apache.lucene.store.ByteBuffersDirectory; 046import org.apache.lucene.store.Directory; 047 048/** Shows facets aggregation by an expression. */ 049public class ExpressionAggregationFacetsExample { 050 051 private final Directory indexDir = new ByteBuffersDirectory(); 052 private final Directory taxoDir = new ByteBuffersDirectory(); 053 private final FacetsConfig config = new FacetsConfig(); 054 055 /** Empty constructor */ 056 public ExpressionAggregationFacetsExample() {} 057 058 /** Build the example index. */ 059 private void index() throws IOException { 060 IndexWriter indexWriter = 061 new IndexWriter( 062 indexDir, new IndexWriterConfig(new WhitespaceAnalyzer()).setOpenMode(OpenMode.CREATE)); 063 064 // Writes facet ords to a separate directory from the main index 065 DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir); 066 067 Document doc = new Document(); 068 doc.add(new TextField("c", "foo bar", Store.NO)); 069 doc.add(new NumericDocValuesField("popularity", 5L)); 070 doc.add(new FacetField("A", "B")); 071 indexWriter.addDocument(config.build(taxoWriter, doc)); 072 073 doc = new Document(); 074 doc.add(new TextField("c", "foo foo bar", Store.NO)); 075 doc.add(new NumericDocValuesField("popularity", 3L)); 076 doc.add(new FacetField("A", "C")); 077 indexWriter.addDocument(config.build(taxoWriter, doc)); 078 079 indexWriter.close(); 080 taxoWriter.close(); 081 } 082 083 /** User runs a query and aggregates facets. */ 084 private FacetResult search() throws IOException, ParseException { 085 DirectoryReader indexReader = DirectoryReader.open(indexDir); 086 IndexSearcher searcher = new IndexSearcher(indexReader); 087 TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir); 088 089 // Aggregate categories by an expression that combines the document's score 090 // and its popularity field 091 Expression expr = JavascriptCompiler.compile("_score * sqrt(popularity)"); 092 SimpleBindings bindings = new SimpleBindings(); 093 bindings.add("_score", DoubleValuesSource.SCORES); // the score of the document 094 bindings.add( 095 "popularity", 096 DoubleValuesSource.fromLongField("popularity")); // the value of the 'popularity' field 097 098 // Aggregates the facet values 099 FacetsCollector fc = new FacetsCollector(true); 100 101 // MatchAllDocsQuery is for "browsing" (counts facets 102 // for all non-deleted docs in the index); normally 103 // you'd use a "normal" query: 104 FacetsCollector.search(searcher, new MatchAllDocsQuery(), 10, fc); 105 106 // Retrieve results 107 Facets facets = 108 new TaxonomyFacetSumValueSource( 109 taxoReader, config, fc, expr.getDoubleValuesSource(bindings)); 110 FacetResult result = facets.getTopChildren(10, "A"); 111 112 indexReader.close(); 113 taxoReader.close(); 114 115 return result; 116 } 117 118 /** Runs the search example. */ 119 public FacetResult runSearch() throws IOException, ParseException { 120 index(); 121 return search(); 122 } 123 124 /** Runs the search and drill-down examples and prints the results. */ 125 public static void main(String[] args) throws Exception { 126 System.out.println("Facet counting example:"); 127 System.out.println("-----------------------"); 128 FacetResult result = new ExpressionAggregationFacetsExample().runSearch(); 129 System.out.println(result); 130 } 131}