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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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package org.elasticsearch.common.lucene.search.morelikethis;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.mlt.MoreLikeThis;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.store.Directory;
import org.elasticsearch.test.ESTestCase;
import java.io.IOException;
import java.io.StringReader;
import java.util.Arrays;
import java.util.List;
public class XMoreLikeThisTests extends ESTestCase {
private void addDoc(RandomIndexWriter writer, String[] texts) throws IOException {
Document doc = new Document();
for (String text : texts) {
doc.add(newTextField("text", text, Field.Store.YES));
}
writer.addDocument(doc);
}
public void testTopN() throws Exception {
int numDocs = 100;
int topN = 25;
// add series of docs with terms of decreasing df
Directory dir = newDirectory();
RandomIndexWriter writer = new RandomIndexWriter(random(), dir);
for (int i = 0; i < numDocs; i++) {
addDoc(writer, generateStrSeq(0, i + 1));
}
IndexReader reader = writer.getReader();
writer.close();
// setup MLT query
MoreLikeThis mlt = new MoreLikeThis(reader);
mlt.setAnalyzer(new MockAnalyzer(random(), MockTokenizer.WHITESPACE, false));
mlt.setMaxQueryTerms(topN);
mlt.setMinDocFreq(1);
mlt.setMinTermFreq(1);
mlt.setMinWordLen(1);
mlt.setFieldNames(new String[]{"text"});
// perform MLT query
String likeText = "";
for (String text : generateStrSeq(0, numDocs)) {
likeText += text + " ";
}
BooleanQuery query = (BooleanQuery) mlt.like("text", new StringReader(likeText));
// check best terms are topN of highest idf
List<BooleanClause> clauses = query.clauses();
assertEquals("Expected" + topN + "clauses only!", topN, clauses.size());
Term[] expectedTerms = new Term[topN];
int idx = 0;
for (String text : generateStrSeq(numDocs - topN, topN)) {
expectedTerms[idx++] = new Term("text", text);
}
for (BooleanClause clause : clauses) {
Term term = ((TermQuery) clause.getQuery()).getTerm();
assertTrue(Arrays.asList(expectedTerms).contains(term));
}
// clean up
reader.close();
dir.close();
}
private String[] generateStrSeq(int from, int size) {
String[] generatedStrings = new String[size];
for (int i = 0; i < generatedStrings.length; i++) {
generatedStrings[i] = String.valueOf(from + i);
}
return generatedStrings;
}
}