Java tutorial
package org.apache.pdfbox.examples.lucene; /* * 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. */ import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.util.Date; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.index.IndexWriterConfig.OpenMode; import org.apache.lucene.index.Term; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; /** * Index all pdf 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. * <p> * It's based on a demo provided by the lucene project. */ public final class IndexPDFFiles { private IndexPDFFiles() { } /** * Index all text files under a directory. * * @param args command line arguments * */ public static void main(String[] args) { String usage = "java org.apache.pdfbox.lucene.IndexPDFFiles" + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n" + "This indexes all PDF 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 File docDir = new File(docsPath); if (!docDir.exists() || !docDir.canRead()) { System.out.println("Document directory '" + docDir.getAbsolutePath() + "' 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(new File(indexPath)); Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_47); IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_47, 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); indexDocs(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()); } } /** * Indexes the given file using the given writer, or if a directory is given, recurses over files and directories * found under the given directory. * * NOTE: This method indexes one document per input file. This is slow. For good throughput, put multiple documents * into your input file(s). An example of this is in the benchmark module, which can create "line doc" files, one * document per line, using the <a * href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html" * >WriteLineDocTask</a>. * * @param writer Writer to the index where the given file/dir info will be stored * @param file The file to index, or the directory to recurse into to find files to index * @throws IOException If there is a low-level I/O error */ static void indexDocs(IndexWriter writer, File file) throws IOException { // do not try to index files that cannot be read if (file.canRead()) { if (file.isDirectory()) { String[] files = file.list(); // an IO error could occur if (files != null) { for (String fileName : files) { indexDocs(writer, new File(file, fileName)); } } } else { FileInputStream fis; try { fis = new FileInputStream(file); } catch (FileNotFoundException fnfe) { // at least on windows, some temporary files raise this exception with an "access denied" message // checking if the file can be read doesn't help return; } try { String path = file.getName().toUpperCase(); Document doc = null; if (path.toLowerCase().endsWith(".pdf")) { System.out.println("Indexing PDF document: " + file); doc = LucenePDFDocument.getDocument(file); } else { System.out.println("Skipping " + file); return; } 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("uid", LucenePDFDocument.createUID(file)), doc); } } finally { fis.close(); } } } } }