Java tutorial
package edu.uci.ics.searcher; /* * 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.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.DirectoryReader; import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.Term; import org.apache.lucene.queryparser.classic.QueryParser; import org.apache.lucene.search.BooleanClause; import org.apache.lucene.search.BooleanClause.Occur; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.BooleanQuery; import org.apache.lucene.search.TermQuery; import org.apache.lucene.search.PhraseQuery; import org.apache.lucene.search.FuzzyQuery; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; import org.apache.lucene.queries.CustomScoreProvider; import org.apache.lucene.queries.CustomScoreQuery; import org.apache.lucene.index.AtomicReaderContext; import org.apache.lucene.search.Explanation; //import org.apache.lucene.index.FieldInvertState; //import org.apache.lucene.search.similarities.Similarity; /** Simple command-line based search demo. */ public class SearchFiles { private SearchFiles() { } /** 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] [-query string] [-raw] [-paging hitsPerPage]\n\nSee http://lucene.apache.org/core/4_1_0/demo/ for details."; 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 queryString = null; 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 ("-query".equals(args[i])) { queryString = 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 ("-paging".equals(args[i])) { hitsPerPage = Integer.parseInt(args[i + 1]); if (hitsPerPage <= 0) { System.err.println("There must be at least 1 hit per page."); System.exit(1); } i++; } } IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index))); IndexSearcher searcher = new IndexSearcher(reader); Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40); BufferedReader in = null; if (queries != null) { in = new BufferedReader(new InputStreamReader(new FileInputStream(queries), "UTF-8")); } else { in = new BufferedReader(new InputStreamReader(System.in, "UTF-8")); } QueryParser parser = new QueryParser(Version.LUCENE_40, field, analyzer); while (true) { 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"); } doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null); 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. * */ 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 url = doc.get("url"); if (url != null) { System.out.println((i + 1) + ". " + url); String title = doc.get("title"); if (title != null) { System.out.println(" Title: " + 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); } } } private static Query myQuery(String query_string) throws Exception { String field = "contents"; Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40); QueryParser parser = new QueryParser(Version.LUCENE_40, field, analyzer); Query query = parser.parse(query_string); return query; } private static Query myBooleanQuery(String query_string) throws Exception { Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40); BooleanQuery bq = new BooleanQuery(); String[] query_tokens = query_string.trim().split(" "); PhraseQuery contents_phrase_query = new PhraseQuery(); PhraseQuery title_phrase_query = new PhraseQuery(); for (int i = 0; i < query_tokens.length; i++) { contents_phrase_query.add(new Term("contents", query_tokens[i]), i); title_phrase_query.add(new Term("title", query_tokens[i]), i); } contents_phrase_query.setBoost(2.0f); title_phrase_query.setBoost(2.0f); bq.add(contents_phrase_query, BooleanClause.Occur.SHOULD); bq.add(title_phrase_query, BooleanClause.Occur.SHOULD); TermQuery contents_term_query = new TermQuery(new Term("contents", query_string)); //contents_term_query.setBoost(1.5f); bq.add(contents_term_query, BooleanClause.Occur.SHOULD); TermQuery title_term_query = new TermQuery(new Term("title", query_string)); bq.add(title_term_query, BooleanClause.Occur.SHOULD); //TermQuery pub_query = new TermQuery(new Term("contents", "publications")); //bq.add(pub_query, BooleanClause.Occur.SHOULD); //FuzzyQuery url_query = new FuzzyQuery(new Term("url", "www.ics.uci.edu"), 2); //bq.add(url_query, BooleanClause.Occur.SHOULD); Query query = new QueryParser(Version.LUCENE_40, "contents", analyzer).parse(bq.toString()); return query; } public static String[] getTopSearchResults(String query_string, int num_of_results) throws Exception { // Read index String index = "index"; IndexReader idxreader = DirectoryReader.open(FSDirectory.open(new File(index))); // Init searcher of the index IndexSearcher searcher = new IndexSearcher(idxreader); // Set up query Query query = myBooleanQuery(query_string); // Addition scoring query CustomScoreQuery myCustomQuery = new MyOwnScoreQuery(query); //TopDocs results = searcher.search(query, num_of_results); TopDocs results = searcher.search(myCustomQuery.createWeight(searcher).getQuery(), num_of_results); ScoreDoc[] hits = results.scoreDocs; String[] top_results = new String[num_of_results]; for (int i = 0; i < num_of_results; i++) { Document doc = searcher.doc(hits[i].doc); String url = doc.get("url"); //System.out.println(url); top_results[i] = url; } return top_results; } static class MyOwnScoreQuery extends CustomScoreQuery { private Query query; public MyOwnScoreQuery(Query query) { super(query); this.query = query; } public CustomScoreProvider getCustomScoreProvider(final AtomicReaderContext reader) { return new CustomScoreProvider(reader) { @Override public float customScore(int doc, float subQueryScore, float valSrcScore) throws IOException { float score = subQueryScore; Document docObject = reader.reader().document(doc); String url = docObject.get("url"); if (url.equals("http://www.ics.uci.edu/")) { //score *= 15; } else if (url.equals("http://www.ics.uci.edu/grad/")) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/grad/courses/") >= 0) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/grad/degrees/") >= 0) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/grad/admissions/") >= 0) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/grad/sao/") >= 0) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/ugrad/sao/") >= 0) { score *= 2; } else if (url.equals("http://www.ics.uci.edu/ugrad/")) { score *= 2; } else if (url.indexOf("http://www.ics.uci.edu/prospective/en/degrees/") >= 0) { score *= 3; } else if (url.indexOf("http://www.ics.uci.edu/faculty/") >= 0) { score *= 1.5; } else if (url.equals("http://archive.ics.uci.edu/ml/")) { score *= 3; } else if (url.equals("http://archive.ics.uci.edu/ml/datasets.html")) { score *= 3; } else if (url.indexOf("http://mlearn.ics.uci.edu/") >= 0) { score *= 2; } else if (url.equals("http://cml.ics.uci.edu/")) { score *= 3; } else if (url.indexOf("http://www.ics.uci.edu/~fielding/") >= 0) { score *= 2; } else if (url.indexOf("http://luci.ics.uci.edu/blog/?") >= 0) { score /= 5; } else if (url.indexOf("http://cgvw.ics.uci.edu/?") >= 0) { score /= 5; } else if (url.indexOf("http://fano.ics.uci.edu/") >= 0) { score /= 2; } else if (url.indexOf("http://www.ics.uci.edu/~eppstein/pix/") >= 0) { score /= 20; // REST } else if (url.indexOf("http://vcp.ics.uci.edu/content/") >= 0) { score /= 10; // REST } long len = Long.parseLong(docObject.get("length")); if (len <= 1500) { if (!url.equals("http://mlearn.ics.uci.edu/")) { score /= (20 / Math.log10(len)); //score /= 3; } } IndexSearcher searcher = new IndexSearcher(reader.reader()); if (url.indexOf("http://www.ics.uci.edu/~johannab/the-rest.html") >= 0) { Explanation exp = searcher.explain(query, doc); //System.out.println(exp); } return score; } }; } } }