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