Lucene example source code file (TestICUTransformFilter.java)

This example Lucene source code file (TestICUTransformFilter.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

any-latin, exception, exception, icutransformfilter, icutransformfilter, io, kat, keywordtokenizer, string, string, stringreader, stringreader, tokenstreamcomponents, traditional-simplified, transliterator

The Lucene TestICUTransformFilter.java source code

package org.apache.lucene.analysis.icu;

/**
 * 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.io.Reader;
import java.io.StringReader;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.KeywordTokenizer;
import org.apache.lucene.analysis.WhitespaceTokenizer;
import org.apache.lucene.analysis.ReusableAnalyzerBase;
import org.apache.lucene.analysis.TokenStream;

import com.ibm.icu.text.Transliterator;
import com.ibm.icu.text.UnicodeSet;


/**
 * Test the ICUTransformFilter with some basic examples.
 */
public class TestICUTransformFilter extends BaseTokenStreamTestCase {
  
  public void testBasicFunctionality() throws Exception {
    checkToken(Transliterator.getInstance("Traditional-Simplified"), 
        "簡化字", "简化字"); 
    checkToken(Transliterator.getInstance("Katakana-Hiragana"), 
        "ヒラガナ", "ひらがな");
    checkToken(Transliterator.getInstance("Fullwidth-Halfwidth"), 
        "アルアノリウ", "ｱﾙｱﾉﾘｳ");
    checkToken(Transliterator.getInstance("Any-Latin"), 
        "Αλφαβητικός Κατάλογος", "Alphabētikós Katálogos");
    checkToken(Transliterator.getInstance("NFD; [:Nonspacing Mark:] Remove"), 
        "Alphabētikós Katálogos", "Alphabetikos Katalogos");
    checkToken(Transliterator.getInstance("Han-Latin"),
        "中国", "zhōng guó");
  }
  
  public void testCustomFunctionality() throws Exception {
    String rules = "a > b; b > c;"; // convert a's to b's and b's to c's
    checkToken(Transliterator.createFromRules("test", rules, Transliterator.FORWARD), "abacadaba", "bcbcbdbcb");
  }
  
  public void testCustomFunctionality2() throws Exception {
    String rules = "c { a > b; a > d;"; // convert a's to b's and b's to c's
    checkToken(Transliterator.createFromRules("test", rules, Transliterator.FORWARD), "caa", "cbd");
  }
  
  public void testOptimizer() throws Exception {
    String rules = "a > b; b > c;"; // convert a's to b's and b's to c's
    Transliterator custom = Transliterator.createFromRules("test", rules, Transliterator.FORWARD);
    assertTrue(custom.getFilter() == null);
    new ICUTransformFilter(new KeywordTokenizer(new StringReader("")), custom);
    assertTrue(custom.getFilter().equals(new UnicodeSet("[ab]")));
  }
  
  public void testOptimizer2() throws Exception {
    checkToken(Transliterator.getInstance("Traditional-Simplified; CaseFold"), 
        "ABCDE", "abcde");
  }
  
  public void testOptimizerSurrogate() throws Exception {
    String rules = "\\U00020087 > x;"; // convert CJK UNIFIED IDEOGRAPH-20087 to an x
    Transliterator custom = Transliterator.createFromRules("test", rules, Transliterator.FORWARD);
    assertTrue(custom.getFilter() == null);
    new ICUTransformFilter(new KeywordTokenizer(new StringReader("")), custom);
    assertTrue(custom.getFilter().equals(new UnicodeSet("[\\U00020087]")));
  }

  private void checkToken(Transliterator transform, String input, String expected) throws IOException {
    TokenStream ts = new ICUTransformFilter(new KeywordTokenizer((new StringReader(input))), transform);
    assertTokenStreamContents(ts, new String[] { expected });
  }
  
  /** blast some random strings through the analyzer */
  public void testRandomStrings() throws Exception {
    final Transliterator transform = Transliterator.getInstance("Any-Latin");
    Analyzer a = new ReusableAnalyzerBase() {
      @Override
      protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
        Tokenizer tokenizer = new WhitespaceTokenizer(TEST_VERSION_CURRENT, reader);
        return new TokenStreamComponents(tokenizer, new ICUTransformFilter(tokenizer, transform));
      }
    };
    checkRandomData(random, a, 1000*RANDOM_MULTIPLIER);
  }
}