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Lucene example source code file (BaseTokenStreamTestCase.java)

This example Lucene source code file (BaseTokenStreamTestCase.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

analyzer, chartermattribute, chartermattribute, checkclearattributesattribute, checkclearattributesattributeimpl, checkclearattributesattributeimpl, integer, io, ioexception, ioexception, override, string, string, stringreader, typeattribute, util

The Lucene BaseTokenStreamTestCase.java source code

package org.apache.lucene.analysis;

/**
 * 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.StringReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
 
import org.apache.lucene.analysis.tokenattributes.*;
import org.apache.lucene.util.Attribute;
import org.apache.lucene.util.AttributeImpl;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util._TestUtil;

/** 
 * Base class for all Lucene unit tests that use TokenStreams. 
 * <p>
 * When writing unit tests for analysis components, its highly recommended
 * to use the helper methods here (especially in conjunction with {@link MockAnalyzer} or
 * {@link MockTokenizer}), as they contain many assertions and checks to 
 * catch bugs.
 * 
 * @see MockAnalyzer
 * @see MockTokenizer
 */
public abstract class BaseTokenStreamTestCase extends LuceneTestCase {
  // some helpers to test Analyzers and TokenStreams:
  
  public static interface CheckClearAttributesAttribute extends Attribute {
    boolean getAndResetClearCalled();
  }

  public static final class CheckClearAttributesAttributeImpl extends AttributeImpl implements CheckClearAttributesAttribute {
    private boolean clearCalled = false;
    
    public boolean getAndResetClearCalled() {
      try {
        return clearCalled;
      } finally {
        clearCalled = false;
      }
    }

    @Override
    public void clear() {
      clearCalled = true;
    }

    @Override
    public boolean equals(Object other) {
      return (
        other instanceof CheckClearAttributesAttributeImpl &&
        ((CheckClearAttributesAttributeImpl) other).clearCalled == this.clearCalled
      );
    }

    @Override
    public int hashCode() {
      return 76137213 ^ Boolean.valueOf(clearCalled).hashCode();
    }
    
    @Override
    public void copyTo(AttributeImpl target) {
      ((CheckClearAttributesAttributeImpl) target).clear();
    }
  }

  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[], String types[], int posIncrements[], Integer finalOffset) throws IOException {
    assertNotNull(output);
    CheckClearAttributesAttribute checkClearAtt = ts.addAttribute(CheckClearAttributesAttribute.class);
    
    assertTrue("has no CharTermAttribute", ts.hasAttribute(CharTermAttribute.class));
    CharTermAttribute termAtt = ts.getAttribute(CharTermAttribute.class);
    
    OffsetAttribute offsetAtt = null;
    if (startOffsets != null || endOffsets != null || finalOffset != null) {
      assertTrue("has no OffsetAttribute", ts.hasAttribute(OffsetAttribute.class));
      offsetAtt = ts.getAttribute(OffsetAttribute.class);
    }
    
    TypeAttribute typeAtt = null;
    if (types != null) {
      assertTrue("has no TypeAttribute", ts.hasAttribute(TypeAttribute.class));
      typeAtt = ts.getAttribute(TypeAttribute.class);
    }
    
    PositionIncrementAttribute posIncrAtt = null;
    if (posIncrements != null) {
      assertTrue("has no PositionIncrementAttribute", ts.hasAttribute(PositionIncrementAttribute.class));
      posIncrAtt = ts.getAttribute(PositionIncrementAttribute.class);
    }
    
    ts.reset();
    for (int i = 0; i < output.length; i++) {
      // extra safety to enforce, that the state is not preserved and also assign bogus values
      ts.clearAttributes();
      termAtt.setEmpty().append("bogusTerm");
      if (offsetAtt != null) offsetAtt.setOffset(14584724,24683243);
      if (typeAtt != null) typeAtt.setType("bogusType");
      if (posIncrAtt != null) posIncrAtt.setPositionIncrement(45987657);
      
      checkClearAtt.getAndResetClearCalled(); // reset it, because we called clearAttribute() before
      assertTrue("token "+i+" does not exist", ts.incrementToken());
      assertTrue("clearAttributes() was not called correctly in TokenStream chain", checkClearAtt.getAndResetClearCalled());
      
      assertEquals("term "+i, output[i], termAtt.toString());
      if (startOffsets != null)
        assertEquals("startOffset "+i, startOffsets[i], offsetAtt.startOffset());
      if (endOffsets != null)
        assertEquals("endOffset "+i, endOffsets[i], offsetAtt.endOffset());
      if (types != null)
        assertEquals("type "+i, types[i], typeAtt.type());
      if (posIncrements != null)
        assertEquals("posIncrement "+i, posIncrements[i], posIncrAtt.getPositionIncrement());
      
      // we can enforce some basic things about a few attributes even if the caller doesn't check:
      if (offsetAtt != null) {
        assertTrue("startOffset must be >= 0", offsetAtt.startOffset() >= 0);
        assertTrue("endOffset must be >= 0", offsetAtt.endOffset() >= 0);
        assertTrue("endOffset must be >= startOffset", offsetAtt.endOffset() >= offsetAtt.startOffset());
      }
      if (posIncrAtt != null) {
        assertTrue("posIncrement must be >= 0", posIncrAtt.getPositionIncrement() >= 0);
      }
    }
    assertFalse("end of stream", ts.incrementToken());
    ts.end();
    if (finalOffset != null)
      assertEquals("finalOffset ", finalOffset.intValue(), offsetAtt.endOffset());
    if (offsetAtt != null) {
      assertTrue("finalOffset must be >= 0", offsetAtt.endOffset() >= 0);
    }
    ts.close();
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[], String types[], int posIncrements[]) throws IOException {
    assertTokenStreamContents(ts, output, startOffsets, endOffsets, types, posIncrements, null);
  }

  public static void assertTokenStreamContents(TokenStream ts, String[] output) throws IOException {
    assertTokenStreamContents(ts, output, null, null, null, null, null);
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, String[] types) throws IOException {
    assertTokenStreamContents(ts, output, null, null, types, null, null);
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, int[] posIncrements) throws IOException {
    assertTokenStreamContents(ts, output, null, null, null, posIncrements, null);
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[]) throws IOException {
    assertTokenStreamContents(ts, output, startOffsets, endOffsets, null, null, null);
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[], Integer finalOffset) throws IOException {
    assertTokenStreamContents(ts, output, startOffsets, endOffsets, null, null, finalOffset);
  }
  
  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[], int[] posIncrements) throws IOException {
    assertTokenStreamContents(ts, output, startOffsets, endOffsets, null, posIncrements, null);
  }

  public static void assertTokenStreamContents(TokenStream ts, String[] output, int startOffsets[], int endOffsets[], int[] posIncrements, Integer finalOffset) throws IOException {
    assertTokenStreamContents(ts, output, startOffsets, endOffsets, null, posIncrements, finalOffset);
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[], String types[], int posIncrements[]) throws IOException {
    assertTokenStreamContents(a.tokenStream("dummy", new StringReader(input)), output, startOffsets, endOffsets, types, posIncrements, input.length());
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output) throws IOException {
    assertAnalyzesTo(a, input, output, null, null, null, null);
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output, String[] types) throws IOException {
    assertAnalyzesTo(a, input, output, null, null, types, null);
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output, int[] posIncrements) throws IOException {
    assertAnalyzesTo(a, input, output, null, null, null, posIncrements);
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[]) throws IOException {
    assertAnalyzesTo(a, input, output, startOffsets, endOffsets, null, null);
  }
  
  public static void assertAnalyzesTo(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[], int[] posIncrements) throws IOException {
    assertAnalyzesTo(a, input, output, startOffsets, endOffsets, null, posIncrements);
  }
  

  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[], String types[], int posIncrements[]) throws IOException {
    assertTokenStreamContents(a.reusableTokenStream("dummy", new StringReader(input)), output, startOffsets, endOffsets, types, posIncrements, input.length());
  }
  
  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output) throws IOException {
    assertAnalyzesToReuse(a, input, output, null, null, null, null);
  }
  
  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output, String[] types) throws IOException {
    assertAnalyzesToReuse(a, input, output, null, null, types, null);
  }
  
  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output, int[] posIncrements) throws IOException {
    assertAnalyzesToReuse(a, input, output, null, null, null, posIncrements);
  }
  
  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[]) throws IOException {
    assertAnalyzesToReuse(a, input, output, startOffsets, endOffsets, null, null);
  }
  
  public static void assertAnalyzesToReuse(Analyzer a, String input, String[] output, int startOffsets[], int endOffsets[], int[] posIncrements) throws IOException {
    assertAnalyzesToReuse(a, input, output, startOffsets, endOffsets, null, posIncrements);
  }

  // simple utility method for testing stemmers
  
  public static void checkOneTerm(Analyzer a, final String input, final String expected) throws IOException {
    assertAnalyzesTo(a, input, new String[]{expected});
  }
  
  public static void checkOneTermReuse(Analyzer a, final String input, final String expected) throws IOException {
    assertAnalyzesToReuse(a, input, new String[]{expected});
  }
  
  // simple utility method for blasting tokenstreams with data to make sure they don't do anything crazy

  public static void checkRandomData(Random random, Analyzer a, int iterations) throws IOException {
    checkRandomData(random, a, iterations, 20);
  }

  public static void checkRandomData(Random random, Analyzer a, int iterations, int maxWordLength) throws IOException {
    for (int i = 0; i < iterations; i++) {
      String text;
      switch(_TestUtil.nextInt(random, 0, 3)) {
        case 0: 
          text = _TestUtil.randomSimpleString(random);
          break;
        case 1:
          text = _TestUtil.randomRealisticUnicodeString(random, maxWordLength);
          break;
        default:
          text = _TestUtil.randomUnicodeString(random, maxWordLength);
      }
      
      TokenStream ts = a.reusableTokenStream("dummy", new StringReader(text));
      assertTrue("has no CharTermAttribute", ts.hasAttribute(CharTermAttribute.class));
      CharTermAttribute termAtt = ts.getAttribute(CharTermAttribute.class);
      List<String> tokens = new ArrayList();
      ts.reset();
      while (ts.incrementToken()) {
        tokens.add(termAtt.toString());
        // TODO: we could collect offsets etc here for better checking that reset() really works.
      }
      ts.end();
      ts.close();
      // verify reusing is "reproducable" and also get the normal tokenstream sanity checks
      if (!tokens.isEmpty())
        assertAnalyzesToReuse(a, text, tokens.toArray(new String[tokens.size()]));
    }
  }
}

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