| /* |
| * 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.lucene.demo.facet; |
| |
| import java.io.IOException; |
| import java.text.ParseException; |
| |
| import org.apache.lucene.analysis.core.WhitespaceAnalyzer; |
| import org.apache.lucene.document.Document; |
| import org.apache.lucene.document.Field.Store; |
| import org.apache.lucene.document.NumericDocValuesField; |
| import org.apache.lucene.document.TextField; |
| import org.apache.lucene.expressions.Expression; |
| import org.apache.lucene.expressions.SimpleBindings; |
| import org.apache.lucene.expressions.js.JavascriptCompiler; |
| import org.apache.lucene.facet.FacetField; |
| 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.TaxonomyFacetSumValueSource; |
| 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.index.IndexWriterConfig.OpenMode; |
| import org.apache.lucene.search.DoubleValuesSource; |
| 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 facets aggregation by an expression. */ |
| public class ExpressionAggregationFacetsExample { |
| |
| private final Directory indexDir = new RAMDirectory(); |
| private final Directory taxoDir = new RAMDirectory(); |
| private final FacetsConfig config = new FacetsConfig(); |
| |
| /** Empty constructor */ |
| public ExpressionAggregationFacetsExample() {} |
| |
| /** Build the example index. */ |
| private void index() throws IOException { |
| IndexWriter indexWriter = new IndexWriter(indexDir, new IndexWriterConfig( |
| new WhitespaceAnalyzer()).setOpenMode(OpenMode.CREATE)); |
| |
| // Writes facet ords to a separate directory from the main index |
| DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir); |
| |
| Document doc = new Document(); |
| doc.add(new TextField("c", "foo bar", Store.NO)); |
| doc.add(new NumericDocValuesField("popularity", 5L)); |
| doc.add(new FacetField("A", "B")); |
| indexWriter.addDocument(config.build(taxoWriter, doc)); |
| |
| doc = new Document(); |
| doc.add(new TextField("c", "foo foo bar", Store.NO)); |
| doc.add(new NumericDocValuesField("popularity", 3L)); |
| doc.add(new FacetField("A", "C")); |
| indexWriter.addDocument(config.build(taxoWriter, doc)); |
| |
| indexWriter.close(); |
| taxoWriter.close(); |
| } |
| |
| /** User runs a query and aggregates facets. */ |
| private FacetResult search() throws IOException, ParseException { |
| DirectoryReader indexReader = DirectoryReader.open(indexDir); |
| IndexSearcher searcher = new IndexSearcher(indexReader); |
| TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir); |
| |
| // Aggregate categories by an expression that combines the document's score |
| // and its popularity field |
| Expression expr = JavascriptCompiler.compile("_score * sqrt(popularity)"); |
| SimpleBindings bindings = new SimpleBindings(); |
| bindings.add("_score", DoubleValuesSource.SCORES); // the score of the document |
| bindings.add("popularity", DoubleValuesSource.fromLongField("popularity")); // the value of the 'popularity' field |
| |
| // Aggregates the facet values |
| FacetsCollector fc = new FacetsCollector(true); |
| |
| // 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 TaxonomyFacetSumValueSource(taxoReader, config, fc, expr.getDoubleValuesSource(bindings)); |
| FacetResult result = facets.getTopChildren(10, "A"); |
| |
| indexReader.close(); |
| taxoReader.close(); |
| |
| return result; |
| } |
| |
| /** Runs the search example. */ |
| public FacetResult runSearch() throws IOException, ParseException { |
| index(); |
| return search(); |
| } |
| |
| /** 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("-----------------------"); |
| FacetResult result = new ExpressionAggregationFacetsExample().runSearch(); |
| System.out.println(result); |
| } |
| } |