Java tutorial
/**************************************************************** * Licensed to the AOS Community (AOS) under one or more * * contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The AOS 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. * ****************************************************************/ package aos.lucene.search.advanced; import junit.framework.TestCase; import java.util.Date; import java.io.IOException; import org.apache.lucene.store.RAMDirectory; import org.apache.lucene.store.Directory; import org.apache.lucene.search.TopDocs; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.document.DateTools; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexReader; import org.apache.lucene.search.Query; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.function.FieldScoreQuery; import org.apache.lucene.search.function.CustomScoreQuery; import org.apache.lucene.search.function.CustomScoreProvider; import org.apache.lucene.search.FieldCache; import org.apache.lucene.util.Version; import io.aos.lucene.util.TestUtil; // From chapter 5 public class FunctionQueryTest extends TestCase { IndexSearcher s; IndexWriter w; private void addDoc(int score, String content) throws Exception { Document doc = new Document(); doc.add(new Field("score", Integer.toString(score), Field.Store.NO, Field.Index.NOT_ANALYZED_NO_NORMS)); doc.add(new Field("content", content, Field.Store.NO, Field.Index.ANALYZED)); w.addDocument(doc); } public void setUp() throws Exception { Directory dir = new RAMDirectory(); w = new IndexWriter(dir, new StandardAnalyzer(Version.LUCENE_46), IndexWriter.MaxFieldLength.UNLIMITED); addDoc(7, "this hat is green"); addDoc(42, "this hat is blue"); w.close(); s = new IndexSearcher(dir, true); } public void tearDown() throws Exception { super.tearDown(); s.close(); } public void testFieldScoreQuery() throws Throwable { Query q = new FieldScoreQuery("score", FieldScoreQuery.Type.BYTE); TopDocs hits = s.search(q, 10); assertEquals(2, hits.scoreDocs.length); // assertEquals(1, hits.scoreDocs[0].doc); // assertEquals(42, (int) hits.scoreDocs[0].score); assertEquals(0, hits.scoreDocs[1].doc); assertEquals(7, (int) hits.scoreDocs[1].score); } /* #1 All documents match #2 Doc 1 is first because its static score (42) is higher than doc 0's (7) */ public void testCustomScoreQuery() throws Throwable { Query q = new QueryParser(Version.LUCENE_46, "content", new StandardAnalyzer(Version.LUCENE_46)) .parse("the green hat"); FieldScoreQuery qf = new FieldScoreQuery("score", FieldScoreQuery.Type.BYTE); CustomScoreQuery customQ = new CustomScoreQuery(q, qf) { public CustomScoreProvider getCustomScoreProvider(IndexReader r) { return new CustomScoreProvider(r) { public float customScore(int doc, float subQueryScore, float valSrcScore) { return (float) (Math.sqrt(subQueryScore) * valSrcScore); } }; } }; TopDocs hits = s.search(customQ, 10); assertEquals(2, hits.scoreDocs.length); assertEquals(1, hits.scoreDocs[0].doc); // assertEquals(0, hits.scoreDocs[1].doc); } /* #1 Even though document 0 is a better match to the original query, document 1 gets a better score after multiplying in its score field */ static class RecencyBoostingQuery extends CustomScoreQuery { double multiplier; int today; int maxDaysAgo; String dayField; static int MSEC_PER_DAY = 1000 * 3600 * 24; public RecencyBoostingQuery(Query q, double multiplier, int maxDaysAgo, String dayField) { super(q); today = (int) (new Date().getTime() / MSEC_PER_DAY); this.multiplier = multiplier; this.maxDaysAgo = maxDaysAgo; this.dayField = dayField; } private class RecencyBooster extends CustomScoreProvider { final int[] publishDay; public RecencyBooster(IndexReader r) throws IOException { super(r); publishDay = FieldCache.DEFAULT // #A .getInts(r, dayField); // #A } public float customScore(int doc, float subQueryScore, float valSrcScore) { int daysAgo = today - publishDay[doc]; // #B if (daysAgo < maxDaysAgo) { // #C float boost = (float) (multiplier * // #D (maxDaysAgo - daysAgo) // #D / maxDaysAgo); // #D return (float) (subQueryScore * (1.0 + boost)); } else { return subQueryScore; // #E } } } public CustomScoreProvider getCustomScoreProvider(IndexReader r) throws IOException { return new RecencyBooster(r); } } /* #A Retrieve days from field cache #B Compute elapsed days #C Skip old books #D Compute simple linear boost #E Return un-boosted score */ public void testRecency() throws Throwable { Directory dir = TestUtil.getBookIndexDirectory(); IndexReader r = DirectoryReader.open(dir); IndexSearcher s = new IndexSearcher(r); s.setDefaultFieldSortScoring(true, true); QueryParser parser = new QueryParser(Version.LUCENE_46, "contents", new StandardAnalyzer(Version.LUCENE_46)); Query q = parser.parse("java in action"); // #A Query q2 = new RecencyBoostingQuery(q, // #B 2.0, 2 * 365, "pubmonthAsDay"); Sort sort = new Sort(new SortField[] { SortField.FIELD_SCORE, new SortField("title2", SortField.STRING) }); TopDocs hits = s.search(q2, null, 5, sort); for (int i = 0; i < hits.scoreDocs.length; i++) { Document doc = r.document(hits.scoreDocs[i].doc); LOGGER.info((1 + i) + ": " + doc.get("title") + ": pubmonth=" + doc.get("pubmonth") + " score=" + hits.scoreDocs[i].score); } s.close(); r.close(); dir.close(); } /* #A Parse query #B Create recency boosting query */ }