Java tutorial
/* * 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 nl.knaw.huygens.timbuctoo.lucene.demoTwo; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.nio.charset.StandardCharsets; import java.nio.file.FileVisitResult; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.SimpleFileVisitor; import java.nio.file.attribute.BasicFileAttributes; import java.util.Date; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.document.LongPoint; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.document.FieldType; import org.apache.lucene.document.StringField; import org.apache.lucene.document.TextField; import org.apache.lucene.index.IndexOptions; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig.OpenMode; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.index.Term; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; import nl.knaw.huygens.timbuctoo.lucene.analyzer.MyAccentAnalyzer; /** * Index all text files under a directory. * <p> * This is a command-line application demonstrating simple Lucene indexing. Run * it with no command-line arguments for usage information. */ public class IndexFiles { private IndexFiles() { } /** Index all text files under a directory. */ public static void main(String[] args) { String usage = "java org.apache.lucene.demo.IndexFiles" + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n" + "This indexes the documents in DOCS_PATH, creating a Lucene index" + "in INDEX_PATH that can be searched with SearchFiles"; String indexPath = "index"; String docsPath = null; boolean create = true; for (int i = 0; i < args.length; i++) { if ("-index".equals(args[i])) { indexPath = args[i + 1]; i++; } else if ("-docs".equals(args[i])) { docsPath = args[i + 1]; i++; } else if ("-update".equals(args[i])) { create = false; } } if (docsPath == null) { System.err.println("Usage: " + usage); System.exit(1); } final Path docDir = Paths.get(docsPath); if (!Files.isReadable(docDir)) { System.out.println("Document directory '" + docDir.toAbsolutePath() + "' does not exist or is not readable, please check the path"); System.exit(1); } Date start = new Date(); try { System.out.println("Indexing to directory '" + indexPath + "'..."); Directory dir = FSDirectory.open(Paths.get(indexPath)); Analyzer analyzer = new MyAccentAnalyzer(); IndexWriterConfig iwc = new IndexWriterConfig(analyzer); if (create) { // Create a new index in the directory, removing any // previously indexed documents: iwc.setOpenMode(OpenMode.CREATE); } else { // Add new documents to an existing index: iwc.setOpenMode(OpenMode.CREATE_OR_APPEND); } // Optional: for better indexing performance, if you // are indexing many documents, increase the RAM // buffer. But if you do this, increase the max heap // size to the JVM (eg add -Xmx512m or -Xmx1g): // // iwc.setRAMBufferSizeMB(256.0); IndexWriter writer = new IndexWriter(dir, iwc); indexTest(writer, docDir); // NOTE: if you want to maximize search performance, // you can optionally call forceMerge here. This can be // a terribly costly operation, so generally it's only // worth it when your index is relatively static (ie // you're done adding documents to it): // // writer.forceMerge(1); writer.close(); Date end = new Date(); System.out.println(end.getTime() - start.getTime() + " total milliseconds"); } catch (IOException e) { System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage()); } } private static void indexTest(IndexWriter writer, Path path) throws IOException { if (Files.isDirectory(path)) { Files.walkFileTree(path, new SimpleFileVisitor<Path>() { @Override public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException { try { indexFields(writer, file, attrs.lastModifiedTime().toMillis()); } catch (IOException ignore) { // don't index files that can't be read. } return FileVisitResult.CONTINUE; } }); } else { indexFields(writer, path, Files.getLastModifiedTime(path).toMillis()); } } private static void indexFields(IndexWriter writer, Path file, long lastModified) throws IOException { try (InputStream stream = Files.newInputStream(file)) { // make a new, empty document Document doc = new Document(); Field pathField = new StringField("path", file.toString(), Field.Store.YES); doc.add(pathField); doc.add(new LongPoint("modified", lastModified)); // Add the contents of the file to a field named "contents". Specify // a Reader, // so that the text of the file is tokenized and indexed, but not // stored. // Note that FileReader expects the file to be in UTF-8 encoding. // If that's not the case searching for special characters will // fail. BufferedReader br = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8)); String line = null; String[] splitLine; String content = ""; boolean inContent = false; while ((line = br.readLine()) != null) { if (inContent && !line.contains(":")) { content += " " + line; } FieldType ft = new FieldType(); ft.setIndexOptions(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS); ft.setStored(true); if (!line.isEmpty() && line.contains(":")) { // System.out.println("line: " + line); splitLine = line.split(":"); if (splitLine[0].equals("content")) { inContent = true; if (splitLine.length > 1) { content += splitLine[1]; } } else if (splitLine[0].equals("end_content")) { inContent = false; // System.out.println("content - " + content.trim()); doc.add(new Field("content", content.trim(), ft)); } else { doc.add(new Field(splitLine[0].trim(), splitLine[1].trim(), ft)); System.out.println(splitLine[0].trim() + " - " + splitLine[1].trim()); } } } if (writer.getConfig().getOpenMode() == OpenMode.CREATE) { // New index, so we just add the document (no old document can // be there): System.out.println("adding " + file); writer.addDocument(doc); } else { // Existing index (an old copy of this document may have been // indexed) so // we use updateDocument instead to replace the old one matching // the exact // path, if present: System.out.println("updating " + file); writer.updateDocument(new Term("path", file.toString()), doc); } } } }