Java tutorial
package insa.luyten; /* * 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.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.util.Date; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.en.EnglishAnalyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.DirectoryReader; import org.apache.lucene.index.IndexReader; import org.apache.lucene.queryparser.classic.QueryParser; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; /** * This class is based on the Lucene Demo SearchFiles class. */ public class SearchCISI implements Runnable { public SearchCISI() { } public void run() { try { this.search(); } catch (Exception e) { e.printStackTrace(); } } private void search() throws Exception { StandardAnalyzer standardAnalyzer = new StandardAnalyzer(Version.LUCENE_47); EnglishAnalyzer englishAnalyzer = new EnglishAnalyzer(Version.LUCENE_47); String[] fields = { "content", "title", "authors", "references" }; Analyzer[] analysers = { englishAnalyzer, englishAnalyzer, standardAnalyzer, englishAnalyzer }; String index = "index"; String field = fields[0]; String queries = null; int repeat = 0; boolean raw = false; String queryString = null; int hitsPerPage = 10; IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index))); IndexSearcher searcher = new IndexSearcher(reader); // :Post-Release-Update-Version.LUCENE_XY: Analyzer analyzer = analysers[0]; BufferedReader in = new BufferedReader(new InputStreamReader(System.in, "UTF-8")); // :Post-Release-Update-Version.LUCENE_XY: while (true) { System.out.println("\nChoose query field :"); for (int i = 0; i < fields.length; i++) { System.out.println(i + 1 + ". " + fields[i]); } int n = Integer.parseInt(in.readLine()) - 1; field = fields[n]; analyzer = analysers[n]; QueryParser parser = new QueryParser(Version.LUCENE_47, field, analyzer); if (queries == null && queryString == null) { // prompt the user System.out.println("Enter query: "); } String line = queryString != null ? queryString : in.readLine(); if (line == null || line.length() == -1) { break; } line = line.trim(); if (line.length() == 0) { break; } Query query = parser.parse(line); System.out.println("Searching for: " + query.toString(field)); if (repeat > 0) { // repeat & time as benchmark Date start = new Date(); for (int i = 0; i < repeat; i++) { searcher.search(query, null, 100); } Date end = new Date(); System.out.println("Time: " + (end.getTime() - start.getTime()) + "ms"); } //catch NewQueryException queryString = null; //by default int nq = 0; try { this.doPagingSearch(in, searcher, query, field, hitsPerPage, raw, queries == null && queryString == null); } catch (NewQueryException e) { String newQueryString = e.getMessage(); System.out.println("Is \"" + newQueryString + "\" a new query ?"); do { System.out.println(" Enter (y)es or (n)o."); String l = in.readLine(); if (l.length() == 1 && l.charAt(0) == 'y') nq = 1; else if (l.length() == 1 && l.charAt(0) == 'n') nq = -1; } while (nq == 0); if (nq == 1) { queryString = newQueryString; } } if (queryString != null && nq == 1) // it's okay ; else if (queryString != null) break; } reader.close(); } /** * This demonstrates a typical paging search scenario, where the search engine presents * pages of size n to the user. The user can then go to the next page if interested in * the next hits. * * When the query is executed for the first time, then only enough results are collected * to fill 5 result pages. If the user wants to page beyond this limit, then the query * is executed another time and all hits are collected. * */ private void doPagingSearch(BufferedReader in, IndexSearcher searcher, Query query, String field, int hitsPerPage, boolean raw, boolean interactive) throws IOException, NewQueryException { // Collect enough docs to show 5 pages TopDocs results = searcher.search(query, 5 * hitsPerPage); ScoreDoc[] hits = results.scoreDocs; int numTotalHits = results.totalHits; System.out.println(numTotalHits + " total matching documents"); int start = 0; int end = Math.min(numTotalHits, hitsPerPage); while (true) { if (end > hits.length) { System.out.println("Only results 1 - " + hits.length + " of " + numTotalHits + " total matching documents collected."); System.out.println("Collect more (y/n) ?"); String line = in.readLine(); if (line.length() == 0 || line.charAt(0) == 'n') { break; } hits = searcher.search(query, numTotalHits).scoreDocs; } end = Math.min(hits.length, start + hitsPerPage); for (int i = start; i < end; i++) { if (raw) { // output raw format System.out.println("doc=" + hits[i].doc + " score=" + hits[i].score); continue; } Document doc = searcher.doc(hits[i].doc); String index = doc.get("index"); if (index != null) { System.out.println((i + 1) + ". " + index); String title = doc.get("title"); if (title != null && (field.equals("content")) || field.equals("title")) { System.out.println(" Title: " + doc.get("title")); } if (field.equals("authors")) { System.out.println(" Authors: " + doc.get(field)); } if (field.equals("references")) { System.out.println(" References: " + doc.get(field)); } } else { System.out.println((i + 1) + ". " + "No path for this document"); } } if (!interactive || end == 0) { break; } if (numTotalHits >= end) { boolean quit = false; while (true) { System.out.print("Press "); if (start - hitsPerPage >= 0) { System.out.print("(p)revious page, "); } if (start + hitsPerPage < numTotalHits) { System.out.print("(n)ext page, "); } System.out.println("(q)uit or enter number to jump to a page."); String line = in.readLine(); //quit if no enter or q if (line.length() == 0 || line.charAt(0) == 'q') { quit = true; break; } //just p if (line.length() == 1 && line.charAt(0) == 'p') { start = Math.max(0, start - hitsPerPage); break; } //just n else if (line.length() == 1 && line.charAt(0) == 'n') { if (start + hitsPerPage < numTotalHits) { start += hitsPerPage; } break; } else { //test if it's a word or a number int page = 0; try { page = Integer.parseInt(line); } //FD: if not a number, maybe a new query ? catch (NumberFormatException e) { throw new NewQueryException(line); } if ((page - 1) * hitsPerPage < numTotalHits) { start = (page - 1) * hitsPerPage; break; } else { System.out.println("No such page"); } } } if (quit) break; end = Math.min(numTotalHits, start + hitsPerPage); } } } }