Java tutorial
package edu.ucdenver.ccp.nlp.index; //package edu.ucdenver.ccp.nlp; /* 004 * Licensed to the Apache Software Foundation (ASF) under one or more 005 * contributor license agreements. See the NOTICE file distributed with 006 * this work for additional information regarding copyright ownership. 007 * The ASF licenses this file to You under the Apache License, Version 2.0 008 * (the "License"); you may not use this file except in compliance with 009 * the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, software 014 * distributed under the License is distributed on an "AS IS" BASIS, 015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 016 * See the License for the specific language governing permissions and 017 * limitations under the License. 018 */ 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.MultiFieldQueryParser; 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.search.TopScoreDocCollector; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; /** Simple command-line based search demo. */ public class Search { private Search() { } /** Simple command-line based search demo. */ public static void main(String[] args) throws Exception { String index = "index"; String queries = null; String queryString = null; int hitsPerPage = 100; IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index))); IndexSearcher searcher = new IndexSearcher(reader); //Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40); EnglishAnalyzer analyzer = new EnglishAnalyzer(Version.LUCENE_40); BufferedReader in = null; in = new BufferedReader(new InputStreamReader(System.in, "UTF-8")); //query building starts here. //QueryParser parser = new QueryParser(Version.LUCENE_40, "title", analyzer); MultiFieldQueryParser parser = new MultiFieldQueryParser(Version.LUCENE_40, new String[] { "title", "abs", "mentions" }, analyzer); while (true) { if (queries == null && queryString == null) { // prompt the user //c for cisplatin 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 q = queryParser.parse(querystr); Query query = parser.parse(line); //System.out.println("Searching for: " + query.toString(field)); TopScoreDocCollector collector = TopScoreDocCollector.create(hitsPerPage, true); searcher.search(query, collector); ScoreDoc[] hits = collector.topDocs().scoreDocs; // 4. display results System.out.println("Found " + hits.length + " hits."); for (int i = 0; i < hits.length; ++i) { int docId = hits[i].doc; Document d = searcher.doc(docId); System.out.println((i + 1) + ". " + d.get("pmid") + "\t" + d.get("title")); } //doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null); if (queryString != null) { break; } } reader.close(); } /** 139 * This demonstrates a typical paging search scenario, where the search engine presents 140 * pages of size n to the user. The user can then go to the next page if interested in 141 * the next hits. 142 * 143 * When the query is executed for the first time, then only enough results are collected 144 * to fill 5 result pages. If the user wants to page beyond this limit, then the query 145 * is executed another time and all hits are collected. 146 * 147 */ /** * @param in * @param searcher * @param query * @param hitsPerPage * @param raw * @param interactive * @throws IOException */ /** * @param in * @param searcher * @param query * @param hitsPerPage * @param raw * @param interactive * @throws IOException */ public static void doPagingSearch(BufferedReader in, IndexSearcher searcher, Query query, int hitsPerPage, boolean raw, boolean interactive) throws IOException { // 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 path = doc.get("path"); //if (path != null) { System.out.print((i + 1)); String title = doc.get("title"); String pmid = doc.get("pmid"); if (title != null || pmid != null) { System.out.println(doc.get("pmid") + " " + doc.get("title")); } //} 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(); if (line.length() == 0 || line.charAt(0) == 'q') { quit = true; break; } if (line.charAt(0) == 'p') { start = Math.max(0, start - hitsPerPage); break; } else if (line.charAt(0) == 'n') { if (start + hitsPerPage < numTotalHits) { start += hitsPerPage; } break; } else { int page = Integer.parseInt(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); } } } }