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Lucene example source code file (PatternAnalyzerTest.java)

This example Lucene source code file (PatternAnalyzerTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

are, fox, fox,the, here,are,some,comma,separated,words, io, ioexception, ioexception, patternanalyzer, patternanalyzer, regex, string, string, stringbuilder, the, the, tokenstream, util

The Lucene PatternAnalyzerTest.java source code

package org.apache.lucene.analysis.miscellaneous;

/**
 * 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.
 */

import java.io.IOException;
import java.util.Arrays;
import java.util.regex.Pattern;

import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.StopAnalyzer;
import org.apache.lucene.analysis.TokenStream;

/**
 * Verifies the behavior of PatternAnalyzer.
 */
public class PatternAnalyzerTest extends BaseTokenStreamTestCase {

  /**
   * Test PatternAnalyzer when it is configured with a non-word pattern.
   * Behavior can be similar to SimpleAnalyzer (depending upon options)
   */
  public void testNonWordPattern() throws IOException {
    // Split on non-letter pattern, do not lowercase, no stopwords
    PatternAnalyzer a = new PatternAnalyzer(TEST_VERSION_CURRENT, PatternAnalyzer.NON_WORD_PATTERN,
        false, null);
    check(a, "The quick brown Fox,the abcd1234 (56.78) dc.", new String[] {
        "The", "quick", "brown", "Fox", "the", "abcd", "dc" });

    // split on non-letter pattern, lowercase, english stopwords
    PatternAnalyzer b = new PatternAnalyzer(TEST_VERSION_CURRENT, PatternAnalyzer.NON_WORD_PATTERN,
        true, StopAnalyzer.ENGLISH_STOP_WORDS_SET);
    check(b, "The quick brown Fox,the abcd1234 (56.78) dc.", new String[] {
        "quick", "brown", "fox", "abcd", "dc" });
  }

  /**
   * Test PatternAnalyzer when it is configured with a whitespace pattern.
   * Behavior can be similar to WhitespaceAnalyzer (depending upon options)
   */
  public void testWhitespacePattern() throws IOException {
    // Split on whitespace patterns, do not lowercase, no stopwords
    PatternAnalyzer a = new PatternAnalyzer(TEST_VERSION_CURRENT, PatternAnalyzer.WHITESPACE_PATTERN,
        false, null);
    check(a, "The quick brown Fox,the abcd1234 (56.78) dc.", new String[] {
        "The", "quick", "brown", "Fox,the", "abcd1234", "(56.78)", "dc." });

    // Split on whitespace patterns, lowercase, english stopwords
    PatternAnalyzer b = new PatternAnalyzer(TEST_VERSION_CURRENT, PatternAnalyzer.WHITESPACE_PATTERN,
        true, StopAnalyzer.ENGLISH_STOP_WORDS_SET);
    check(b, "The quick brown Fox,the abcd1234 (56.78) dc.", new String[] {
        "quick", "brown", "fox,the", "abcd1234", "(56.78)", "dc." });
  }

  /**
   * Test PatternAnalyzer when it is configured with a custom pattern. In this
   * case, text is tokenized on the comma ","
   */
  public void testCustomPattern() throws IOException {
    // Split on comma, do not lowercase, no stopwords
    PatternAnalyzer a = new PatternAnalyzer(TEST_VERSION_CURRENT, Pattern.compile(","), false, null);
    check(a, "Here,Are,some,Comma,separated,words,", new String[] { "Here",
        "Are", "some", "Comma", "separated", "words" });

    // split on comma, lowercase, english stopwords
    PatternAnalyzer b = new PatternAnalyzer(TEST_VERSION_CURRENT, Pattern.compile(","), true,
        StopAnalyzer.ENGLISH_STOP_WORDS_SET);
    check(b, "Here,Are,some,Comma,separated,words,", new String[] { "here",
        "some", "comma", "separated", "words" });
  }

  /**
   * Test PatternAnalyzer against a large document.
   */
  public void testHugeDocument() throws IOException {
    StringBuilder document = new StringBuilder();
    // 5000 a's
    char largeWord[] = new char[5000];
    Arrays.fill(largeWord, 'a');
    document.append(largeWord);

    // a space
    document.append(' ');

    // 2000 b's
    char largeWord2[] = new char[2000];
    Arrays.fill(largeWord2, 'b');
    document.append(largeWord2);

    // Split on whitespace patterns, do not lowercase, no stopwords
    PatternAnalyzer a = new PatternAnalyzer(TEST_VERSION_CURRENT, PatternAnalyzer.WHITESPACE_PATTERN,
        false, null);
    check(a, document.toString(), new String[] { new String(largeWord),
        new String(largeWord2) });
  }

  /**
   * Verify the analyzer analyzes to the expected contents. For PatternAnalyzer,
   * several methods are verified:
   * <ul>
   * <li>Analysis with a normal Reader
   * <li>Analysis with a FastStringReader
   * <li>Analysis with a String
   * </ul>
   */
  private void check(PatternAnalyzer analyzer, String document,
      String expected[]) throws IOException {
    // ordinary analysis of a Reader
    assertAnalyzesTo(analyzer, document, expected);

    // analysis with a "FastStringReader"
    TokenStream ts = analyzer.tokenStream("dummy",
        new PatternAnalyzer.FastStringReader(document));
    assertTokenStreamContents(ts, expected);

    // analysis of a String, uses PatternAnalyzer.tokenStream(String, String)
    TokenStream ts2 = analyzer.tokenStream("dummy", document);
    assertTokenStreamContents(ts2, expected);
  }
}

Other Lucene examples (source code examples)

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