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Java > Open Source Codes > org > apache > lucene > search > TestSimilarity


1 package org.apache.lucene.search;
2
3 /**
4  * Copyright 2004 The Apache Software Foundation
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import junit.framework.TestCase;
20
21 import java.util.Collection JavaDoc;
22
23 import org.apache.lucene.index.Term;
24 import org.apache.lucene.index.IndexWriter;
25 import org.apache.lucene.search.IndexSearcher;
26 import org.apache.lucene.store.RAMDirectory;
27 import org.apache.lucene.analysis.SimpleAnalyzer;
28 import org.apache.lucene.document.Document;
29 import org.apache.lucene.document.Field;
30
31 /** Similarity unit test.
32  *
33  * @author Doug Cutting
34  * @version $Revision: 1.4 $
35  */
36 public class TestSimilarity extends TestCase {
37   public TestSimilarity(String JavaDoc name) {
38     super(name);
39   }
40   
41   public static class SimpleSimilarity extends Similarity {
42     public float lengthNorm(String JavaDoc field, int numTerms) { return 1.0f; }
43     public float queryNorm(float sumOfSquaredWeights) { return 1.0f; }
44     public float tf(float freq) { return freq; }
45     public float sloppyFreq(int distance) { return 2.0f; }
46     public float idf(Collection JavaDoc terms, Searcher searcher) { return 1.0f; }
47     public float idf(int docFreq, int numDocs) { return 1.0f; }
48     public float coord(int overlap, int maxOverlap) { return 1.0f; }
49   }
50
51   public void testSimilarity() throws Exception JavaDoc {
52     RAMDirectory store = new RAMDirectory();
53     IndexWriter writer = new IndexWriter(store, new SimpleAnalyzer(), true);
54     writer.setSimilarity(new SimpleSimilarity());
55     
56     Document d1 = new Document();
57     d1.add(Field.Text("field", "a c"));
58
59     Document d2 = new Document();
60     d2.add(Field.Text("field", "a b c"));
61     
62     writer.addDocument(d1);
63     writer.addDocument(d2);
64     writer.optimize();
65     writer.close();
66
67     final float[] scores = new float[4];
68
69     Searcher searcher = new IndexSearcher(store);
70     searcher.setSimilarity(new SimpleSimilarity());
71
72     Term a = new Term("field", "a");
73     Term b = new Term("field", "b");
74     Term c = new Term("field", "c");
75
76     searcher.search
77       (new TermQuery(b),
78        new HitCollector() {
79          public final void collect(int doc, float score) {
80            assertTrue(score == 1.0f);
81          }
82        });
83
84     BooleanQuery bq = new BooleanQuery();
85     bq.add(new TermQuery(a), false, false);
86     bq.add(new TermQuery(b), false, false);
87     //System.out.println(bq.toString("field"));
88 searcher.search
89       (bq,
90        new HitCollector() {
91          public final void collect(int doc, float score) {
92            //System.out.println("Doc=" + doc + " score=" + score);
93 assertTrue(score == (float)doc+1);
94          }
95        });
96
97     PhraseQuery pq = new PhraseQuery();
98     pq.add(a);
99     pq.add(c);
100     //System.out.println(pq.toString("field"));
101 searcher.search
102       (pq,
103        new HitCollector() {
104          public final void collect(int doc, float score) {
105            //System.out.println("Doc=" + doc + " score=" + score);
106 assertTrue(score == 1.0f);
107          }
108        });
109
110     pq.setSlop(2);
111     //System.out.println(pq.toString("field"));
112 searcher.search
113       (pq,
114        new HitCollector() {
115          public final void collect(int doc, float score) {
116            //System.out.println("Doc=" + doc + " score=" + score);
117 assertTrue(score == 2.0f);
118          }
119        });
120   }
121 }
122
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