Java tutorial
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See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/ package io.datalayer.lucene.search; 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.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; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Simple command-line based search demo. */ public class FileSearcherMain { private static final Logger LOGGER = LoggerFactory.getLogger(FileSearcherMain.class); /** * 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/java/4_0/demo.html for details."; if ((args.length > 0) && ("-h".equals(args[0]) || "-help".equals(args[0]))) { LOGGER.info(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_46); 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_46, field, analyzer); while (true) { if ((queries == null) && (queryString == null)) { // prompt the user LOGGER.info("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); LOGGER.info("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(); LOGGER.info("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; LOGGER.info(numTotalHits + " total matching documents"); int start = 0; int end = Math.min(numTotalHits, hitsPerPage); while (true) { if (end > hits.length) { LOGGER.info("Only results 1 - " + hits.length + " of " + numTotalHits + " total matching documents collected."); LOGGER.info("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 LOGGER.info("doc=" + hits[i].doc + " score=" + hits[i].score); continue; } /* * Document doc = searcher.doc(hits[i].doc); String path = * doc.get("path"); if (path != null) { LOGGER.info((i + 1) + * ". " + path); String title = doc.get("title"); if (title != * null) { LOGGER.info(" Title: " + doc.get("title")); } } * else { LOGGER.info((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, "); } LOGGER.info("(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 { LOGGER.info("No such page"); } } } if (quit) break; end = Math.min(numTotalHits, start + hitsPerPage); } } } }