lucene源码分析(3)facet实例

public class SimpleFacetsExample { ?private final Directory indexDir = new RAMDirectory(); ?private final Directory taxoDir = new RAMDirectory(); ?private final FacetsConfig config = new FacetsConfig(); ?/** Empty constructor */ ?public SimpleFacetsExample() { ???config.setHierarchical("Publish Date", true); ?} ???/** 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 FacetField("Author", "Bob")); ???doc.add(new FacetField("Publish Date", "2010", "10", "15")); ???indexWriter.addDocument(config.build(taxoWriter, doc)); ???doc = new Document(); ???doc.add(new FacetField("Author", "Lisa")); ???doc.add(new FacetField("Publish Date", "2010", "10", "20")); ???indexWriter.addDocument(config.build(taxoWriter, doc)); ???doc = new Document(); ???doc.add(new FacetField("Author", "Lisa")); ???doc.add(new FacetField("Publish Date", "2012", "1", "1")); ???indexWriter.addDocument(config.build(taxoWriter, doc)); ???doc = new Document(); ???doc.add(new FacetField("Author", "Susan")); ???doc.add(new FacetField("Publish Date", "2012", "1", "7")); ???indexWriter.addDocument(config.build(taxoWriter, doc)); ???doc = new Document(); ???doc.add(new FacetField("Author", "Frank")); ???doc.add(new FacetField("Publish Date", "1999", "5", "5")); ???indexWriter.addDocument(config.build(taxoWriter, doc)); ???????indexWriter.close(); ???taxoWriter.close(); ?} ?/** User runs a query and counts facets. */ ?private List<FacetResult> facetsWithSearch() 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); ???// Retrieve results ???List<FacetResult> results = new ArrayList<>(); ???// Count both "Publish Date" and "Author" dimensions ???Facets facets = new FastTaxonomyFacetCounts(taxoReader, config, fc); ???results.add(facets.getTopChildren(10, "Author")); ???results.add(facets.getTopChildren(10, "Publish Date")); ???????indexReader.close(); ???taxoReader.close(); ???????return results; ?} ???/** User runs a query and counts facets only without collecting the matching documents.*/ ?private List<FacetResult> facetsOnly() 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: ???searcher.search(new MatchAllDocsQuery(), fc); ???// Retrieve results ???List<FacetResult> results = new ArrayList<>(); ???// Count both "Publish Date" and "Author" dimensions ???Facets facets = new FastTaxonomyFacetCounts(taxoReader, config, fc); ??????results.add(facets.getTopChildren(10, "Author")); ???results.add(facets.getTopChildren(10, "Publish Date")); ???????indexReader.close(); ???taxoReader.close(); ???????return results; ?} ???/** User drills down on ‘Publish Date/2010‘, and we ??* ?return facets for ‘Author‘ */ ?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("Publish Date", "2010"); ???FacetsCollector fc = new FacetsCollector(); ???FacetsCollector.search(searcher, q, 10, fc); ???// Retrieve results ???Facets facets = new FastTaxonomyFacetCounts(taxoReader, config, fc); ???FacetResult result = facets.getTopChildren(10, "Author"); ???indexReader.close(); ???taxoReader.close(); ???????return result; ?} ?/** User drills down on ‘Publish Date/2010‘, and we ??* ?return facets for both ‘Publish Date‘ and ‘Author‘, ??* ?using DrillSideways. */ ?private List<FacetResult> drillSideways() 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("Publish Date", "2010"); ???DrillSideways ds = new DrillSideways(searcher, config, taxoReader); ???DrillSidewaysResult result = ds.search(q, 10); ???// Retrieve results ???List<FacetResult> facets = result.facets.getAllDims(10); ???indexReader.close(); ???taxoReader.close(); ???????return facets; ?} ?/** Runs the search example. */ ?public List<FacetResult> runFacetOnly() throws IOException { ???index(); ???return facetsOnly(); ?} ???/** Runs the search example. */ ?public List<FacetResult> runSearch() throws IOException { ???index(); ???return facetsWithSearch(); ?} ???/** Runs the drill-down example. */ ?public FacetResult runDrillDown() throws IOException { ???index(); ???return drillDown(); ?} ?/** Runs the drill-sideways example. */ ?public List<FacetResult> runDrillSideways() throws IOException { ???index(); ???return drillSideways(); ?} ?/** 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("-----------------------"); ???SimpleFacetsExample example = new SimpleFacetsExample(); ???List<FacetResult> results1 = example.runFacetOnly(); ???System.out.println("Author: " + results1.get(0)); ???System.out.println("Publish Date: " + results1.get(1)); ???????System.out.println("Facet counting example (combined facets and search):"); ???System.out.println("-----------------------"); ???List<FacetResult> results = example.runSearch(); ???System.out.println("Author: " + results.get(0)); ???System.out.println("Publish Date: " + results.get(1)); ???????System.out.println("Facet drill-down example (Publish Date/2010):"); ???System.out.println("---------------------------------------------"); ???System.out.println("Author: " + example.runDrillDown()); ???System.out.println("Facet drill-sideways example (Publish Date/2010):"); ???System.out.println("---------------------------------------------"); ???for(FacetResult result : example.runDrillSideways()) { ?????System.out.println(result); ???} ?} ?}

 ?/** Lower-level search API. ??* ??* <p>{@link LeafCollector#collect(int)} is called for every matching document. ??* ??* @throws BooleanQuery.TooManyClauses If a query would exceed ???* ????????{@link BooleanQuery#getMaxClauseCount()} clauses. ??*/ ?public void search(Query query, Collector results) ???throws IOException { ???query = rewrite(query); ???search(leafContexts, createWeight(query, results.needsScores(), 1), results); ?}