1 package org.apache.lucene.analysis.ngram;
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21 import java.io.StringReader;
23 import org.apache.lucene.analysis.BaseTokenStreamTestCase;
26 * Tests {@link NGramTokenizer} for correctness.
28 public class NGramTokenizerTest extends BaseTokenStreamTestCase {
29 private StringReader input;
32 public void setUp() throws Exception {
34 input = new StringReader("abcde");
37 public void testInvalidInput() throws Exception {
38 boolean gotException = false;
40 new NGramTokenizer(input, 2, 1);
41 } catch (IllegalArgumentException e) {
44 assertTrue(gotException);
47 public void testInvalidInput2() throws Exception {
48 boolean gotException = false;
50 new NGramTokenizer(input, 0, 1);
51 } catch (IllegalArgumentException e) {
54 assertTrue(gotException);
57 public void testUnigrams() throws Exception {
58 NGramTokenizer tokenizer = new NGramTokenizer(input, 1, 1);
59 assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);
62 public void testBigrams() throws Exception {
63 NGramTokenizer tokenizer = new NGramTokenizer(input, 2, 2);
64 assertTokenStreamContents(tokenizer, new String[]{"ab","bc","cd","de"}, new int[]{0,1,2,3}, new int[]{2,3,4,5}, 5 /* abcde */);
67 public void testNgrams() throws Exception {
68 NGramTokenizer tokenizer = new NGramTokenizer(input, 1, 3);
69 assertTokenStreamContents(tokenizer,
70 new String[]{"a","b","c","d","e", "ab","bc","cd","de", "abc","bcd","cde"},
71 new int[]{0,1,2,3,4, 0,1,2,3, 0,1,2},
72 new int[]{1,2,3,4,5, 2,3,4,5, 3,4,5},
77 public void testOversizedNgrams() throws Exception {
78 NGramTokenizer tokenizer = new NGramTokenizer(input, 6, 7);
79 assertTokenStreamContents(tokenizer, new String[0], new int[0], new int[0], 5 /* abcde */);
82 public void testReset() throws Exception {
83 NGramTokenizer tokenizer = new NGramTokenizer(input, 1, 1);
84 assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);
85 tokenizer.reset(new StringReader("abcde"));
86 assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);