Java tutorial
package com.yangxu.searchengine.index; /** * 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.cn.smart.SmartChineseAnalyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.document.NumericField; import org.apache.lucene.index.FieldInfo.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 com.yangxu.searchengine.data.Blog; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.io.LineNumberReader; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; /** * 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 final String indexPath = "e:\\crawler\\temp\\blog.csdn.net\\index\\"; private final String docsPath = "e:\\crawler\\temp\\blog.csdn.net\\processed\\"; private IndexFiles() { } /** * * @param createOrUpdate * create update */ public void createIndex(boolean createOrUpdate) { if (docsPath == null) { System.err.println("docsPath not exists!"); 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 SmartChineseAnalyzer(Version.LUCENE_31); IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_31, analyzer); if (createOrUpdate) { // 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 */ private void indexDocs(IndexWriter writer, File file) throws IOException { // do not try to index files that cannot be read // title String titleValue = null; // content String contentValue = null; String urlValue = null; String indextimeValue = null; String uploadtimeValue = null; if (file.canRead()) { if (file.isDirectory()) { String[] files = file.list(); // an IO error could occur if (files != null) { for (int i = 0; i < files.length; i++) { indexDocs(writer, new File(file, files[i])); } } } else { FileInputStream fis; try { fis = new FileInputStream(file); LineNumberReader reader = new LineNumberReader(new InputStreamReader(fis, "UTF-8")); String line = null; StringBuilder sb = new StringBuilder(); while ((line = reader.readLine()) != null) { // int lineNumber = reader.getLineNumber(); switch (reader.getLineNumber()) { case 1: urlValue = line; break; case 2: uploadtimeValue = line; break; case 3: titleValue = line.split(":")[1]; break; case 4: break; default: sb.append(line); break; } /* * if (reader.getLineNumber() == 1) { urlValue = line; } * * if (reader.getLineNumber() == 3) { titleValue = * line.split(":")[1]; } else if (reader.getLineNumber() * > 4) { sb.append(line); } */ } contentValue = sb.toString(); reader.close(); } 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 { // make a new, empty document Document doc = new 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: Field urlField = new Field("url", urlValue, Field.Store.YES, Field.Index.NOT_ANALYZED); urlField.setIndexOptions(IndexOptions.DOCS_ONLY); doc.add(urlField); Field titleField = new Field("title", titleValue, Field.Store.YES, Field.Index.ANALYZED); titleField.setIndexOptions(IndexOptions.DOCS_ONLY); doc.add(titleField); Field contentField = new Field("content", contentValue, Field.Store.YES, Field.Index.ANALYZED); contentField.setIndexOptions(IndexOptions.DOCS_ONLY); doc.add(contentField); // Add the last modified date of the file a field named // "modified". // Use a NumericField 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. SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd HH:mm:ss"); //Calendar cal = Calendar.getInstance(); // //timeValue = formatter.format(cal.getTime()); Date now = new Date(); indextimeValue = formatter.format(now); Field indextimeField = new Field("indextime", indextimeValue, Field.Store.YES, Field.Index.NOT_ANALYZED); titleField.setIndexOptions(IndexOptions.DOCS_ONLY); doc.add(indextimeField); Field uploadtimeField = new Field("uploadtime", uploadtimeValue, Field.Store.YES, Field.Index.NOT_ANALYZED); titleField.setIndexOptions(IndexOptions.DOCS_ONLY); doc.add(uploadtimeField); // 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 Field("contents", new BufferedReader( // new InputStreamReader(fis, "UTF-8")))); 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("url", urlValue), doc); writer.updateDocument(new Term("title", titleValue), doc); writer.updateDocument(new Term("content", contentValue), doc); writer.updateDocument(new Term("indextime", String.valueOf(indextimeValue)), doc); writer.updateDocument(new Term("uploadtime", String.valueOf(uploadtimeValue)), doc); } } finally { fis.close(); } } } } /** Index all text files under a directory. */ public static void main(String[] args) { boolean createOrUpdate = true; IndexFiles indexFiles = new IndexFiles(); indexFiles.createIndex(createOrUpdate); } }