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* 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.
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package org.apache.lucene.search.uhighlight;
import java.io.IOException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.postingshighlight.CustomSeparatorBreakIterator;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util.QueryBuilder;
public class LengthGoalBreakIteratorTest extends LuceneTestCase {
private static final String FIELD = "body";
// We test LengthGoalBreakIterator as it is used by the UnifiedHighlighter instead of directly, because it is
// not a general purpose BreakIterator. A unit test of it directly wouldn't give as much confidence.
private final Analyzer analyzer =
new MockAnalyzer(random(), MockTokenizer.SIMPLE, true);//whitespace, punctuation, lowercase
// We do a '.' BreakIterator and test varying the length goal.
// 0 1
// 01234567890123456789
static final String CONTENT = "Aa bb. Cc dd. Ee ff";
public void testTargetLen() throws IOException {
// "goal" means target length goal to find closest break
// at first word:
Query query = query("aa");
assertEquals("almost two sent",
"<b>Aa</b> bb.", highlightClosestToLen(CONTENT, query, 9));
assertEquals( "barely two sent",
"<b>Aa</b> bb. Cc dd.", highlightClosestToLen(CONTENT, query, 10));
assertEquals("long goal",
"<b>Aa</b> bb. Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20)));
// at some word not at start of passage
query = query("dd");
assertEquals("short goal",
" Cc <b>dd</b>.", highlightClosestToLen(CONTENT, query, random().nextInt(5)));
assertEquals("almost two sent",
" Cc <b>dd</b>.", highlightClosestToLen(CONTENT, query, 10));
assertEquals("barely two sent",
" Cc <b>dd</b>. Ee ff", highlightClosestToLen(CONTENT, query, 11));
assertEquals("long goal",
" Cc <b>dd</b>. Ee ff", highlightClosestToLen(CONTENT, query, 12 + random().nextInt(20)));
}
public void testMinLen() throws IOException {
// minLen mode is simpler than targetLen... just test a few cases
Query query = query("dd");
assertEquals("almost two sent",
" Cc <b>dd</b>.", highlightMinLen(CONTENT, query, 6));
assertEquals("barely two sent",
" Cc <b>dd</b>. Ee ff", highlightMinLen(CONTENT, query, 7));
}
public void testDefaultSummaryTargetLen() throws IOException {
Query query = query("zz");
assertEquals("Aa bb.",
highlightClosestToLen(CONTENT, query, random().nextInt(10))); // < 10
assertEquals("Aa bb. Cc dd.",
highlightClosestToLen(CONTENT, query, 10 + 6)); // cusp of adding 3rd sentence
assertEquals("Aa bb. Cc dd. Ee ff",
highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20))); // >= 14
}
private Query query(String qStr) {
return new QueryBuilder(analyzer).createBooleanQuery(FIELD, qStr);
}
private String highlightClosestToLen(String content, Query query, int lengthGoal) throws IOException {
UnifiedHighlighter highlighter = new UnifiedHighlighter(null, analyzer);
highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createClosestToLength(new CustomSeparatorBreakIterator('.'), lengthGoal));
return highlighter.highlightWithoutSearcher(FIELD, query, content, 1).toString();
}
private String highlightMinLen(String content, Query query, int lengthGoal) throws IOException {
// differs from above only by "createMinLength"
UnifiedHighlighter highlighter = new UnifiedHighlighter(null, analyzer);
highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createMinLength(new CustomSeparatorBreakIterator('.'), lengthGoal));
return highlighter.highlightWithoutSearcher(FIELD, query, content, 1).toString();
}
}