Java tutorial
package cs571.proj1; /* * 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 org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.document.FieldType; import org.apache.lucene.document.LongField; import org.apache.lucene.document.StringField; import org.apache.lucene.document.TextField; import org.apache.lucene.index.IndexOptions; import org.apache.lucene.index.IndexReader; 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 java.io.BufferedReader; import java.io.ByteArrayInputStream; 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.Arrays; import java.util.Date; import java.util.HashSet; import java.util.Set; /** 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() { } public static boolean tfidf = false; public static boolean bm25 = false; /** 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; } else if ("-tfidf".equals(args[i])) { tfidf = true; } else if ("-bm25".equals(args[i])) { bm25 = true; } } 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 StandardAnalyzer(); IndexWriterConfig iwc = new IndexWriterConfig(analyzer); if (tfidf) iwc.setSimilarity(new TFIDF()); if (bm25) iwc.setSimilarity(new BM25()); 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"); System.out.println("Total # of Docs Indexed: " + numOfDocuments); } 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 path 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(final 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 { indexDoc(writer, file, attrs.lastModifiedTime().toMillis()); } catch (IOException ignore) { // don't index files that can't be read. } return FileVisitResult.CONTINUE; } }); } else { indexDoc(writer, path, Files.getLastModifiedTime(path).toMillis()); } } protected static boolean checkForIgnoredFile(String fileName) { for (String s : ignore_file) { if (fileName.equals(s)) return true; } return false; } protected static boolean checkForIgnoreLine(String line) { for (String s : ignore_line) { if (line.trim().equals(s)) return true; } return false; } protected static String removeTags(String line) { int beginIndex = line.indexOf('>'); int endIndex = line.lastIndexOf('<'); if (beginIndex == -1 || endIndex == -1 || beginIndex > endIndex) { System.out.println(line); return null; } return line.substring(beginIndex + 1, endIndex).trim(); } // private static boolean checkForIgnoreStartsWith(String line) { // for(String s : ignore_startsWith){ // if(line.startsWith(s)) return true; // } // return false; // } public final static String docStart = "<DOC>"; public final static String docEnd = "</DOC>"; public final static String textStart = "<TEXT>"; public final static String textEnd = "</TEXT>"; public final static Set<String> ignore_line = new HashSet<>( Arrays.asList("<p>", "</p>", "<ABS>", "<AU>", "<DATE1>", "<H1>", "<HEADER>", "<HT>", "<TEXT>", "<TR>", "<BYLINE>", "<CORRECTION>", "<CORRECTION-DATE>", "<DATE>", "<DATELINE>", "<GRAPHIC>", "<LENGTH>", "<SECTION>", "<SUBJECT>", "<TYPE>")); public final static Set<String> ignore_startsWith = new HashSet<>(Arrays.asList("Language: ", "Article Type:")); public final static Set<String> ignore_file = new HashSet<>( Arrays.asList("readchg.txt", "readmefb.txt", "readfrcg", "readmeft", "readmela.txt")); public final static String docNO_start = "<DOCNO>"; public final static String docID_start = "<DOCID>"; public static int numOfDocuments = 0; /** Indexes a single document */ static void indexDoc(IndexWriter writer, Path file, long lastModified) throws IOException { if (checkForIgnoredFile(file.getFileName().toString())) return; try (InputStream stream = Files.newInputStream(file)) { // make a new, empty document // Add the path of the file as a field named "path". Use a // field that is indexed (i.e. searchable), but don't tokenize // the field into separate words and don't index term frequency // or positional information: // Add the last modified date of the file a field named "modified". // Use a LongField that is indexed (i.e. efficiently filterable with // NumericRangeFilter). This indexes to milli-second resolution, which // is often too fine. You could instead create a number based on // year/month/day/hour/minutes/seconds, down the resolution you require. // For example the long value 2011021714 would mean // February 17, 2011, 2-3 PM. // 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. //doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8)))); BufferedReader br = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8)); String line, docNO = null, docID = null, s; StringBuilder sb = new StringBuilder(); Field docIDField = null; Document doc = new Document(); boolean docFound = false; // boolean testOut = false; // PrintWriter pw = new PrintWriter("out.txt"); while ((line = br.readLine()) != null) { line = line.trim(); //To-do detect document boundaries if (line.startsWith(docNO_start)) { docNO = removeTags(line); continue; } if (line.startsWith(docID_start)) { docID = removeTags(line); continue; } // if(checkForIgnoreStartsWith(line)){continue;} // if(checkForIgnoreLine(line)){continue;} if (line.equals(docStart)) { docFound = true; //testOut = true; continue; } if (line.equals(docEnd)) { docFound = false; if (docNO != null) { docIDField = new StringField("docID", docNO, Field.Store.YES); doc.add(docIDField); } else if (docID != null) { docIDField = new StringField("docID", docID, Field.Store.YES); doc.add(docIDField); } else { continue; } //doc.add(new TermVector("contents",sb.toString(),Field.Store.NO)); if (tfidf || bm25) { FieldType tv = new FieldType(); tv.setTokenized(true); tv.setStoreTermVectors(true); tv.setIndexOptions(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS); s = sb.toString(); byte[] bytes = s.getBytes(); ByteArrayInputStream bstream = new ByteArrayInputStream(bytes); InputStreamReader isr = new InputStreamReader(bstream); doc.add(new Field("contents", isr, tv)); } else { doc.add(new TextField("contents", sb.toString(), Field.Store.NO)); } Field pathField = new StringField("path", file.toString(), Field.Store.YES); doc.add(pathField); doc.add(new LongField("modified", lastModified, Field.Store.NO)); numOfDocuments++; sb.setLength(0); // testOut = false; // pw.close(); 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); } doc = new Document(); continue; } if (docFound) { sb.append(line).append("\n"); // if(testOut) pw.println(line); } } } } }