List of usage examples for org.apache.lucene.index DirectoryReader indexExists
public static boolean indexExists(Directory directory) throws IOException
true if an index likely exists at the specified directory. From source file:de.jetsli.lumeo.RawLucene.java
License:Apache License
public RawLucene init() { indexLock();/*from w w w . j av a 2 s .c om*/ try { if (closed) throw new IllegalStateException("Already closed"); if (writer != null) throw new IllegalStateException("Already initialized"); // release locks when started if (IndexWriter.isLocked(dir)) { logger.warn("index is locked + " + name + " -> releasing lock"); IndexWriter.unlock(dir); } IndexWriterConfig cfg = new IndexWriterConfig(VERSION, defaultMapping.getCombinedAnalyzer()); LogByteSizeMergePolicy mp = new LogByteSizeMergePolicy(); mp.setMaxMergeMB(getMaxMergeMB()); cfg.setRAMBufferSizeMB(ramBufferSizeMB); cfg.setTermIndexInterval(termIndexIntervalSize); cfg.setMergePolicy(mp); // TODO specify different formats for id fields etc // -> this breaks 16 of our tests!? Lucene Bug? // cfg.setCodec(new Lucene40Codec() { // // @Override public PostingsFormat getPostingsFormatForField(String field) { // return new Pulsing40PostingsFormat(); // } // }); // cfg.setMaxThreadStates(8); boolean create = !DirectoryReader.indexExists(dir); cfg.setOpenMode(create ? IndexWriterConfig.OpenMode.CREATE : IndexWriterConfig.OpenMode.APPEND); //wrap the writer with a tracking index writer writer = new TrackingIndexWriter(new IndexWriter(dir, cfg)); nrtManager = new NRTManager(writer, new SearcherFactory() { // @Override // public IndexSearcher newSearcher(IndexReader reader) throws IOException { // //TODO do some kind of warming here? // return new IndexSearcher(reader); // } }); getCurrentRTCache(latestGen); int priority = Math.min(Thread.currentThread().getPriority() + 2, Thread.MAX_PRIORITY); flushThread = new FlushThread("flush-thread"); flushThread.setPriority(priority); flushThread.setDaemon(true); flushThread.start(); reopenThread = new NRTManagerReopenThread(nrtManager, ordinaryWaiting, incomingSearchesMaximumWaiting); reopenThread.setName("NRT Reopen Thread"); reopenThread.setPriority(priority); reopenThread.setDaemon(true); reopenThread.start(); return this; } catch (Exception e) { throw new RuntimeException(e); } finally { indexUnlock(); } }
From source file:de.twitterlivesearch.analysis.Searcher.java
License:Apache License
/** * This is the same as//from w w w . j ava 2 s . co m * {@link de.twitterlivesearch.analysis.Searcher#searchForTweets(String) * searchForTweets(String)}, but the search is limited to the tweet with the * given id. This can for example be used to analyze the latest incoming * tweet. * * @param id * @param queryString * @return */ public List<Document> searchForTweets(Integer id, String queryString) { if (queryString.isEmpty()) { return Collections.emptyList(); } AbstractConfiguration config = ConfigurationHolder.getConfiguration(); try { if (!DirectoryReader.indexExists(directory)) { return null; } } catch (IOException e) { log.fatal("Error when trying to check if directory exists!", e); return new ArrayList<>(); } DirectoryReader ireader; try { ireader = DirectoryReader.open(directory); } catch (IOException e) { log.fatal("Error when trying to open directory!", e); return null; } IndexSearcher isearcher = new IndexSearcher(ireader); Query textQuery = null; QueryParser parser = new QueryParser(FieldNames.TEXT.getField(), AnalyzerMapping.getInstance().ANALYZER_FOR_DELIMITER); parser.setDefaultOperator(config.getDefaultOperator()); BooleanQuery query = new BooleanQuery(); try { textQuery = parser.parse(queryString); } catch (ParseException e) { log.fatal("Error while parsing query: " + queryString, e); } // if id does not equal null only the query with the given id will be // searched // this can be used to search the latest element only if (id != null) { Query idQuery = NumericRangeQuery.newIntRange(FieldNames.ID.getField(), id.intValue(), id.intValue(), true, true); query.add(idQuery, Occur.MUST); } query.add(textQuery, Occur.MUST); ScoreDoc[] hits = null; try { hits = isearcher.search(query, 1000).scoreDocs; } catch (IOException e) { log.fatal("Error while trying to search!", e); } List<Document> result = new ArrayList<>(); for (int i = 0; i < hits.length; i++) { try { result.add(isearcher.doc(hits[i].doc)); log.info("Found result for query \"" + queryString + "\"."); } catch (IOException e) { log.fatal("Error when getting document!", e); } } return result; }
From source file:edu.illinois.cs.cogcomp.bigdata.lucene.Lucene.java
License:Open Source License
public static boolean indexExists(String pageIndex) { try {// ww w . ja v a 2 s . co m return DirectoryReader.indexExists(new NIOFSDirectory(Paths.get(pageIndex))); } catch (IOException e) { e.printStackTrace(); } return false; }
From source file:edu.stanford.muse.index.Indexer.java
License:Apache License
/** * sets up indexer just for reading... if needed for writing only, call * setupForWrite. if need both read & write, call both. *//*w w w.j a v a 2 s . c om*/ synchronized void setupForRead() { log.info("setting up index for read only access"); long startTime = System.currentTimeMillis(); //closeHandles(); try { setupDirectory(); String[] defaultSearchFields, defaultSearchFieldsOriginal; String[] defaultSearchFieldSubject = new String[] { "title" }; // for subject only search String[] defaultSearchFieldCorrespondents; //body field should be there, as the content of the attachment lies in this field, should also include meta field? //why the search over en-names and en-names-original when body/body_original is included in the search fields? defaultSearchFields = new String[] { "body", "title", "to_names", "from_names", "cc_names", "bcc_names", "to_emails", "from_emails", "cc_emails", "bcc_emails" }; defaultSearchFieldsOriginal = new String[] { "body_original", "title" }; // we want to leave title there because we want to always hit the title -- discussed with Peter June 27 2015 defaultSearchFieldCorrespondents = new String[] { "to_names", "from_names", "cc_names", "bcc_names", "to_emails", "from_emails", "cc_emails", "bcc_emails" }; // names field added above after email discussion with Sit 6/11/2013. problem is that we're not using the Lucene EnglishPossessiveFilter, so // NER will extract the name Stanford University in a sentence like: // "This is Stanford University's website." // but when the user clicks on the name "Stanford University" in say monthly cards, we // will not match the message with this sentence because of the apostrophe. //for searching an attchment with fileName String[] metaSearchFields = new String[] { "fileName" }; // Parse a simple query that searches for "text": if (parser == null) { //parser = new QueryParser(MUSE_LUCENE_VERSION, defaultSearchField, analyzer); parser = new MultiFieldQueryParser(LUCENE_VERSION, defaultSearchFields, analyzer); parserOriginal = new MultiFieldQueryParser(LUCENE_VERSION, defaultSearchFieldsOriginal, analyzer); parserSubject = new MultiFieldQueryParser(LUCENE_VERSION, defaultSearchFieldSubject, analyzer); parserCorrespondents = new MultiFieldQueryParser(LUCENE_VERSION, defaultSearchFieldCorrespondents, analyzer); parserMeta = new MultiFieldQueryParser(LUCENE_VERSION, metaSearchFields, new KeywordAnalyzer()); } /** * Bunch of gotchas here * Its a bad idea to store lucene internal docIds, as no assumptions about the internal docIds should be made; * not even that they are serial. When searching, lucene may ignore logically deleted docs. * Lucene does not handle deleted docs, and having these docs in search may bring down the search performance by 50% * Deleted docs are cleaned only during merging of indices.*/ int numContentDocs = 0, numContentDeletedDocs = 0, numAttachmentDocs = 0, numAttachmentDeletedDocs = 0; if (DirectoryReader.indexExists(directory)) { DirectoryReader ireader = DirectoryReader.open(directory); if (ireader.numDeletedDocs() > 0) log.warn("!!!!!!!\nIndex reader has " + ireader.numDocs() + " doc(s) of which " + ireader.numDeletedDocs() + " are deleted)\n!!!!!!!!!!"); isearcher = new IndexSearcher(ireader); contentDocIds = new LinkedHashMap<>(); numContentDocs = ireader.numDocs(); numContentDeletedDocs = ireader.numDeletedDocs(); Bits liveDocs = MultiFields.getLiveDocs(ireader); Set<String> fieldsToLoad = new HashSet<>(); fieldsToLoad.add("docId"); for (int i = 0; i < ireader.maxDoc(); i++) { org.apache.lucene.document.Document doc = ireader.document(i, fieldsToLoad); if (liveDocs != null && !liveDocs.get(i)) continue; if (doc == null || doc.get("docId") == null) continue; contentDocIds.put(i, doc.get("docId")); } log.info("Loaded: " + contentDocIds.size() + " content docs"); } if (DirectoryReader.indexExists(directory_blob)) { IndexReader ireader_blob = DirectoryReader.open(directory_blob); isearcher_blob = new IndexSearcher(ireader_blob); // read-only=true blobDocIds = new LinkedHashMap<Integer, String>(); numAttachmentDocs = ireader_blob.numDocs(); numAttachmentDeletedDocs = ireader_blob.numDeletedDocs(); Bits liveDocs = MultiFields.getLiveDocs(ireader_blob); Set<String> fieldsToLoad = new HashSet<String>(); fieldsToLoad.add("docId"); for (int i = 0; i < ireader_blob.maxDoc(); i++) { org.apache.lucene.document.Document doc = ireader_blob.document(i, fieldsToLoad); if (liveDocs != null && !liveDocs.get(i)) continue; if (doc == null || doc.get("docId") == null) continue; blobDocIds.put(i, doc.get("docId")); } log.info("Loaded: " + blobDocIds.size() + " attachment docs"); } log.warn("Number of content docs: " + numContentDocs + ", number deleted: " + numContentDeletedDocs); log.warn("Number of attachment docs: " + numAttachmentDocs + ", number deleted: " + numAttachmentDeletedDocs); if (dirNameToDocIdMap == null) dirNameToDocIdMap = new LinkedHashMap<String, Map<Integer, String>>(); } catch (Exception e) { Util.print_exception(e, log); } log.info("Setting up index for read took " + (System.currentTimeMillis() - startTime) + " ms"); }
From source file:edu.usc.ir.geo.gazetteer.GeoNameResolver.java
License:Apache License
/** * Build the gazetteer index line by line * * @param gazetteerPath/*from w ww.j a v a2s . c om*/ * path of the gazetteer file * @param indexerPath * path to the created Lucene index directory. * @throws IOException * @throws RuntimeException */ public void buildIndex(String gazetteerPath, String indexerPath) throws IOException { File indexfile = new File(indexerPath); indexDir = FSDirectory.open(indexfile.toPath()); if (!DirectoryReader.indexExists(indexDir)) { IndexWriterConfig config = new IndexWriterConfig(analyzer); indexWriter = new IndexWriter(indexDir, config); Logger logger = Logger.getLogger(this.getClass().getName()); logger.log(Level.WARNING, "Start Building Index for Gazatteer"); BufferedReader filereader = new BufferedReader( new InputStreamReader(new FileInputStream(gazetteerPath), "UTF-8")); String line; int count = 0; while ((line = filereader.readLine()) != null) { try { count += 1; if (count % 100000 == 0) { logger.log(Level.INFO, "Indexed Row Count: " + count); } addDoc(indexWriter, line); } catch (RuntimeException re) { logger.log(Level.WARNING, "Skipping... Error on line: {}", line); } } logger.log(Level.WARNING, "Building Finished"); filereader.close(); indexWriter.close(); } }
From source file:fr.paris.lutece.plugins.directory.service.directorysearch.DirectorySearchService.java
License:Open Source License
/** * Process indexing/* w ww .j a va 2 s . c o m*/ * @param bCreate true for start full indexing * false for begin incremental indexing * @return the log */ public String processIndexing(boolean bCreate) { StringBuffer sbLogs = new StringBuffer(); IndexWriter writer = null; boolean bCreateIndex = bCreate; try { sbLogs.append("\r\nIndexing all contents ...\r\n"); if (!DirectoryReader.indexExists(_luceneDirectory)) { //init index bCreateIndex = true; } if (!bCreateIndex && IndexWriter.isLocked(_luceneDirectory)) { IndexWriter.unlock(_luceneDirectory); } IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_46, _analyzer); if (bCreateIndex) { conf.setOpenMode(OpenMode.CREATE); } else { conf.setOpenMode(OpenMode.APPEND); } writer = new IndexWriter(_luceneDirectory, conf); Date start = new Date(); sbLogs.append("\r\n<strong>Indexer : "); sbLogs.append(_indexer.getName()); sbLogs.append(" - "); sbLogs.append(_indexer.getDescription()); sbLogs.append("</strong>\r\n"); _indexer.processIndexing(writer, bCreateIndex, sbLogs); Date end = new Date(); sbLogs.append("Duration of the treatment : "); sbLogs.append(end.getTime() - start.getTime()); sbLogs.append(" milliseconds\r\n"); } catch (Exception e) { sbLogs.append(" caught a "); sbLogs.append(e.getClass()); sbLogs.append("\n with message: "); sbLogs.append(e.getMessage()); sbLogs.append("\r\n"); AppLogService.error("Indexing error : " + e.getMessage(), e); } finally { try { if (writer != null) { writer.close(); } } catch (IOException e) { AppLogService.error(e.getMessage(), e); } } return sbLogs.toString(); }
From source file:fr.paris.lutece.plugins.document.service.docsearch.DocSearchService.java
License:Open Source License
/** * Indexing documents for searching/*from w ww . ja v a 2 s. c om*/ * @param bCreate tell if it's total indexing or total (total = true) * @return indexing logs */ public String processIndexing(boolean bCreate) { StringBuilder sbLogs = new StringBuilder(); IndexWriter writer = null; boolean bCreateIndex = bCreate; try { sbLogs.append("\r\nIndexing all contents ...\r\n"); Directory dir = NIOFSDirectory.open(new File(_strIndex)); if (!DirectoryReader.indexExists(dir)) { //init index bCreateIndex = true; } Date start = new Date(); IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_46, _analyzer); if (bCreateIndex) { conf.setOpenMode(OpenMode.CREATE); } else { conf.setOpenMode(OpenMode.APPEND); } writer = new IndexWriter(dir, conf); if (!bCreateIndex) { //incremental indexing //add all document which must be add for (IndexerAction action : getAllIndexerActionByTask(IndexerAction.TASK_CREATE)) { try { ArrayList<Integer> luceneDocumentId = new ArrayList<Integer>(); luceneDocumentId.add(action.getIdDocument()); List<org.apache.lucene.document.Document> luceneDocument = _indexer .getDocuments(luceneDocumentId); if ((luceneDocument != null) && (luceneDocument.size() > 0)) { Iterator<org.apache.lucene.document.Document> it = luceneDocument.iterator(); while (it.hasNext()) { org.apache.lucene.document.Document doc = it.next(); writer.addDocument(doc); sbLogs.append("Adding "); sbLogs.append(doc.get(DocSearchItem.FIELD_TYPE)); sbLogs.append(" #"); sbLogs.append(doc.get(DocSearchItem.FIELD_UID)); sbLogs.append(" - "); sbLogs.append(doc.get(DocSearchItem.FIELD_TITLE)); sbLogs.append("\r\n"); } } } catch (IOException e) { sbLogs.append("Error durign document indexation parsing."); sbLogs.append("\r\n"); } removeIndexerAction(action.getIdAction()); } //Update all document which must be update for (IndexerAction action : getAllIndexerActionByTask(IndexerAction.TASK_MODIFY)) { try { ArrayList<Integer> luceneDocumentId = new ArrayList<Integer>(); luceneDocumentId.add(action.getIdDocument()); List<org.apache.lucene.document.Document> luceneDocument = _indexer .getDocuments(luceneDocumentId); if ((luceneDocument != null) && (luceneDocument.size() > 0)) { Iterator<org.apache.lucene.document.Document> it = luceneDocument.iterator(); while (it.hasNext()) { org.apache.lucene.document.Document doc = it.next(); writer.updateDocument( new Term(DocSearchItem.FIELD_UID, Integer.toString(action.getIdDocument())), doc); sbLogs.append("Updating "); sbLogs.append(doc.get(DocSearchItem.FIELD_TYPE)); sbLogs.append(" #"); sbLogs.append(doc.get(DocSearchItem.FIELD_UID)); sbLogs.append(" - "); sbLogs.append(doc.get(DocSearchItem.FIELD_TITLE)); sbLogs.append("\r\n"); } } } catch (IOException e) { sbLogs.append("Error durign document indexation parsing."); sbLogs.append("\r\n"); } removeIndexerAction(action.getIdAction()); } //delete all document which must be delete for (IndexerAction action : getAllIndexerActionByTask(IndexerAction.TASK_DELETE)) { writer.deleteDocuments( new Term(DocSearchItem.FIELD_UID, Integer.toString(action.getIdDocument()))); sbLogs.append("Deleting "); sbLogs.append(" #"); sbLogs.append(action.getIdDocument()); sbLogs.append("\r\n"); removeIndexerAction(action.getIdAction()); } } else { //delete all incremental action removeAllIndexerAction(); Collection<Integer> listIdDocuments = DocumentHome.findAllPrimaryKeys(); ArrayList<Integer> luceneDocumentId; for (Integer nIdDocument : listIdDocuments) { try { luceneDocumentId = new ArrayList<Integer>(); luceneDocumentId.add(nIdDocument); List<Document> listDocuments = _indexer.getDocuments(luceneDocumentId); for (Document doc : listDocuments) { writer.addDocument(doc); sbLogs.append("Indexing "); sbLogs.append(doc.get(DocSearchItem.FIELD_TYPE)); sbLogs.append(" #"); sbLogs.append(doc.get(DocSearchItem.FIELD_UID)); sbLogs.append(" - "); sbLogs.append(doc.get(DocSearchItem.FIELD_TITLE)); sbLogs.append("\r\n"); } } catch (IOException e) { sbLogs.append("Error durign document indexation parsing."); sbLogs.append("\r\n"); } } } Date end = new Date(); sbLogs.append("Duration of the treatment : "); sbLogs.append(end.getTime() - start.getTime()); sbLogs.append(" milliseconds\r\n"); } catch (Exception e) { sbLogs.append(" caught a "); sbLogs.append(e.getClass()); sbLogs.append("\n with message: "); sbLogs.append(e.getMessage()); sbLogs.append("\r\n"); AppLogService.error("Indexing error : " + e.getMessage(), e); } finally { try { if (writer != null) { writer.close(); } } catch (IOException e) { AppLogService.error(e.getMessage(), e); } } return sbLogs.toString(); }
From source file:fr.paris.lutece.plugins.search.solr.indexer.SolrIndexerService.java
License:Open Source License
/** * Process the indexing// w w w .j a v a2 s . c o m * @param bCreate tell if it's total indexing or total (total = true) * @return the result log of the indexing */ public static synchronized String processIndexing(boolean bCreate) { // String buffer for building the response page; _sbLogs = new StringBuffer(); Plugin plugin = PluginService.getPlugin(SolrPlugin.PLUGIN_NAME); boolean bCreateIndex = bCreate; String strWebappName = getWebAppName(); try { Directory dir = IndexationService.getDirectoryIndex(); if (!DirectoryReader.indexExists(dir)) { //init index bCreateIndex = true; } Date start = new Date(); if (bCreateIndex) { _sbLogs.append("\r\nIndexing all contents ...\r\n"); // Remove all indexed values of this site SOLR_SERVER.deleteByQuery(SearchItem.FIELD_UID + ":" + strWebappName + SolrConstants.CONSTANT_UNDERSCORE + SolrConstants.CONSTANT_WILDCARD); for (SolrIndexer solrIndexer : INDEXERS) { if (solrIndexer.isEnable()) { _sbLogs.append("\r\n<strong>Indexer : "); _sbLogs.append(solrIndexer.getName()); _sbLogs.append(" - "); _sbLogs.append(solrIndexer.getDescription()); _sbLogs.append("</strong>\r\n"); //the indexer will call write(doc) List<String> lstErrors = solrIndexer.indexDocuments(); if (lstErrors != null) { for (String strError : lstErrors) { _sbLogs.append("<strong>ERROR : "); _sbLogs.append(strError); _sbLogs.append("</strong>\r\n"); } } } } // Remove all actions of the database SolrIndexerActionHome.removeAll(plugin); } else { _sbLogs.append("\r\nIncremental Indexing ...\r\n"); //incremental indexing Collection<SolrIndexerAction> actions = SolrIndexerActionHome.getList(plugin); for (SolrIndexerAction action : actions) { // catch any exception coming from an indexer to prevent global indexation to fail try { SolrIndexer indexer = findSolrIndexer(action.getTypeResource()); if (indexer == null) { _sbLogs.append(" - ERROR : "); _sbLogs.append(" No indexer found for the resource name : ") .append(action.getTypeResource()); _sbLogs.append("</strong>\r\n"); continue; } if (action.getIdTask() == IndexerAction.TASK_DELETE) { if (action.getIdPortlet() != IndexationService.ALL_DOCUMENT) { //delete only the index linked to this portlet SOLR_SERVER.deleteByQuery(SearchItem.FIELD_DOCUMENT_PORTLET_ID + ":" + action.getIdDocument() + "&" + Integer.toString(action.getIdPortlet())); } else { //delete all index linked to uid. We get the uid of the resource to prefix it like we do during the indexation SOLR_SERVER.deleteByQuery(SearchItem.FIELD_UID + ":" + strWebappName + SolrConstants.CONSTANT_UNDERSCORE + indexer.getResourceUid(action.getIdDocument(), action.getTypeResource())); } _sbLogs.append("Deleting "); _sbLogs.append(" #"); _sbLogs.append(action.getIdDocument()); _sbLogs.append("\r\n"); } else { List<SolrItem> lstItems = indexer.getDocuments(action.getIdDocument()); if ((lstItems != null) && !lstItems.isEmpty()) { for (SolrItem item : lstItems) { if ((action.getIdPortlet() == IndexationService.ALL_DOCUMENT) || ((item.getDocPortletId() != null) && item.getDocPortletId() .equals(item.getUid() + "&" + action.getIdPortlet()))) { if (action.getIdTask() == IndexerAction.TASK_CREATE) { _sbLogs.append("Adding "); } else if (action.getIdTask() == IndexerAction.TASK_MODIFY) { _sbLogs.append("Updating "); } SOLR_SERVER.add(solrItem2SolrInputDocument(item)); SOLR_SERVER.commit(); _sbLogs.append(item.getType()); _sbLogs.append(" #"); _sbLogs.append(item.getUid()); _sbLogs.append(" - "); _sbLogs.append(item.getTitle()); _sbLogs.append("\r\n"); } } } } SolrIndexerActionHome.remove(action.getIdAction(), plugin); } catch (Exception e) { _sbLogs.append("\r\n<strong>Action from indexer : "); _sbLogs.append(action.getIndexerName()); _sbLogs.append(" Action ID : ").append(action.getIdAction()).append(" - Document ID : ") .append(action.getIdDocument()); _sbLogs.append(" - ERROR : "); _sbLogs.append(e.getMessage()) .append((e.getCause() != null) ? (" : " + e.getCause().getMessage()) : SolrConstants.CONSTANT_EMPTY_STRING); _sbLogs.append("</strong>\r\n"); } } //reindexing all pages. SOLR_SERVER.deleteByQuery(SearchItem.FIELD_TYPE + ":" + PARAM_TYPE_PAGE); for (SolrIndexer indexer : INDEXERS) { if (indexer.isEnable() && SolrPageIndexer.NAME.equals(indexer.getName())) { indexer.indexDocuments(); break; } } } SOLR_SERVER.commit(); SOLR_SERVER.optimize(); Date end = new Date(); _sbLogs.append("Duration of the treatment : "); _sbLogs.append(end.getTime() - start.getTime()); _sbLogs.append(" milliseconds\r\n"); } catch (Exception e) { _sbLogs.append(" caught a "); _sbLogs.append(e.getClass()); _sbLogs.append("\n with message: "); _sbLogs.append(e.getMessage()); _sbLogs.append("\r\n"); AppLogService.error("Indexing error : " + e.getMessage(), e); } return _sbLogs.toString(); }
From source file:io.github.msurdi.redeye.core.lucene.AbstractIndex.java
License:Apache License
/** * This method provides a very simplistic view of the lucene status. * * @return true if the lucene exists, false otherwise. * @throws IOException/* ww w . j ava 2 s. co m*/ */ @Override public boolean isOk() throws IOException { return DirectoryReader.indexExists(index); }
From source file:it.giacomobergami.lucenepdfindexer.lucene.ClosedLuceneIndex.java
License:Open Source License
public boolean exists() { try {/* w w w . j a v a 2s .c om*/ return DirectoryReader.indexExists(index); } catch (IOException e) { e.printStackTrace(); return false; } }