Java tutorial
package reviews.searching; /** * 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.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Date; import org.apache.lucene.analysis.TokenStream; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.analysis.tokenattributes.TermAttribute; import org.apache.lucene.analysis.tokenattributes.TypeAttribute; import org.apache.lucene.document.Document; import org.apache.lucene.index.FilterIndexReader; import org.apache.lucene.index.IndexReader; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.Collector; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.Scorer; import org.apache.lucene.search.Searcher; import org.apache.lucene.search.TopScoreDocCollector; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; import reviews.indexing.IndexReviews; /** Simple command-line based search demo. */ public class SearchReviews { /** * Use the norms from one field for all fields. Norms are read into memory, * using a byte of memory per document per searched field. This can cause * search of large collections with a large number of fields to run out of * memory. If all of the fields contain only a single token, then the norms * are all identical, then single norm vector may be shared. */ private static class OneNormsReader extends FilterIndexReader { private String field; public OneNormsReader(IndexReader in, String field) { super(in); this.field = field; } @Override public byte[] norms(String field) throws IOException { return in.norms(this.field); } } private SearchReviews() { } /** Simple command-line based search demo. */ public static void main(String[] args) throws Exception { String usage = "Usage:\tjava org.apache.lucene.demo.SearchFiles [-index dir] [-field f] [-repeat n] [-queries file] [-raw] [-norms field] [-paging hitsPerPage]"; usage += "\n\tSpecify 'false' for hitsPerPage to use streaming instead of paging search."; if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) { System.out.println(usage); System.exit(0); } String index = "index"; String field = "contents"; String queries = null; int repeat = 0; boolean raw = false; String normsField = null; boolean paging = true; int hitsPerPage = 10; for (int i = 0; i < args.length; i++) { if ("-index".equals(args[i])) { index = args[i + 1]; i++; } else if ("-field".equals(args[i])) { field = args[i + 1]; i++; } else if ("-queries".equals(args[i])) { queries = args[i + 1]; i++; } else if ("-repeat".equals(args[i])) { repeat = Integer.parseInt(args[i + 1]); i++; } else if ("-raw".equals(args[i])) { raw = true; } else if ("-norms".equals(args[i])) { normsField = args[i + 1]; i++; } else if ("-paging".equals(args[i])) { if (args[i + 1].equals("false")) { paging = false; } else { hitsPerPage = Integer.parseInt(args[i + 1]); if (hitsPerPage == 0) { paging = false; } } i++; } } IndexReader reader = IndexReader.open(FSDirectory.open(new File(index)), true); // only searching, so // read-only=true if (normsField != null) reader = new OneNormsReader(reader, normsField); Searcher searcher = new IndexSearcher(reader); StandardAnalyzer standardAnalyzer = new StandardAnalyzer(Version.LUCENE_30, IndexReviews.STOPWORDS); BufferedReader in = null; if (queries != null) { in = new BufferedReader(new FileReader(queries)); } else { in = new BufferedReader(new InputStreamReader(System.in, "UTF-8")); } QueryParser parser = new QueryParser(Version.LUCENE_30, field, standardAnalyzer); while (true) { if (queries == null) // prompt the user System.out.println("Enter query: "); String line = 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"); } if (paging) { doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null); } else { doStreamingSearch(searcher, query); } } reader.close(); } /** * This method uses a custom HitCollector implementation which simply prints * out the docId and score of every matching document. * * This simulates the streaming search use case, where all hits are supposed * to be processed, regardless of their relevance. */ public static void doStreamingSearch(final Searcher searcher, Query query) throws IOException { Collector streamingHitCollector = new Collector() { private Scorer scorer; private int docBase; // simply print docId and score of every matching document @Override public void collect(int doc) throws IOException { System.out.println("doc=" + doc + docBase + " score=" + scorer.score()); } @Override public boolean acceptsDocsOutOfOrder() { return true; } @Override public void setNextReader(IndexReader reader, int docBase) throws IOException { this.docBase = docBase; } @Override public void setScorer(Scorer scorer) throws IOException { this.scorer = scorer; } }; searcher.search(query, streamingHitCollector); } public static void displayTokenStream(TokenStream tokenStream) throws IOException { TermAttribute termAtt = (TermAttribute) tokenStream.getAttribute(TermAttribute.class); TypeAttribute typeAtt = (TypeAttribute) tokenStream.getAttribute(TypeAttribute.class); while (tokenStream.incrementToken()) { System.out.println(termAtt.term()); System.out.println("Type: " + typeAtt.type()); System.out.println(); } } /** * 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. * */ public static void doPagingSearch(BufferedReader in, Searcher searcher, Query query, int hitsPerPage, boolean raw, boolean interactive) throws IOException { // Collect enough docs to show 5 pages TopScoreDocCollector collector = TopScoreDocCollector.create(5 * hitsPerPage, false); searcher.search(query, collector); ScoreDoc[] hits = collector.topDocs().scoreDocs; int numTotalHits = collector.getTotalHits(); 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; } collector = TopScoreDocCollector.create(numTotalHits, false); searcher.search(query, collector); hits = collector.topDocs().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.println((i + 1) + ". " + path); String title = doc.get("title"); if (title != null) ;// System.out.println("Title: " + doc.get("title")); // HTMLParser parser = new HTMLParser(new File(path)); // Reader reader = parser.getReader(); /* SentenceTokenizer sentTok = new SentenceTokenizer(reader); while (sentTok.incrementToken()) { displayTokenStream(sentTok); } */ /* String contents = ""; int c; while ((c = reader.read()) != -1) { char buf[] = Character.toChars(c); contents += String.valueOf(buf); } //System.out.println("contents "); //System.out.println(contents); // creates a StanfordCoreNLP object, with POS tagging, parsing Properties props = new Properties(); props.put("annotators", "tokenize, ssplit"); StanfordCoreNLP pipeline = new StanfordCoreNLP(props); Annotation document = new Annotation(contents); // run all Annotators on this text pipeline.annotate(document); List<CoreMap> sentences = document.get(SentencesAnnotation.class); for (CoreMap sentence : sentences) { //System.out.println("sentence: " + sentence.toString()); System.out.println("sentence: " + sentence.get(TextAnnotation.class)); // traversing the words in the current sentence System.out.println("Has the following words: "); for (CoreLabel token : sentence.get(TokensAnnotation.class)) { // this is the text of the token String word = token.get(TextAnnotation.class); System.out.print(word + " "); } System.out.println(); } */ } else { System.out.println((i + 1) + ". " + "No path for this document"); } } if (!interactive) { 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); } } } }