Lucene5学习之自定义同义词分词器简单示例

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      同义词功能在全文搜索时的意义，大家应该都懂的。今天中文我就试着写了一个同义词分词的示例demo，其实主要代码还是参考Lucene in Action 这本英文版书籍的随书代码，只不过Lucenen in Action书里的示例代码目前最新版只支持到Lucene4.x,对于Lucene5.x,代码需要稍作修改，下面是基于Lucene5.x的自定义同义词分词器demo:

 

package com.yida.framework.lucene5.analyzer.synonym;

import java.io.IOException;
/**
 * 同义词提取引擎
 * @author Lanxiaowei
 *
 */
public interface SynonymEngine {
	String[] getSynonyms(String s) throws IOException;
}

 

package com.yida.framework.lucene5.analyzer.synonym;

import java.io.IOException;
import java.util.HashMap;

public class BaseSynonymEngine implements SynonymEngine {
	private static HashMap map = new HashMap();
	
	{
		map.put("quick", new String[] {"fast","speedy"});
		map.put("jumps", new String[] {"leaps","hops"});
		map.put("over", new String[] {"above"});
		map.put("lazy", new String[] {"apathetic","slugish"});
		map.put("dog", new String[] {"canine","pooch"});
	}

	public String[] getSynonyms(String s) throws IOException {
		return map.get(s);
	}
}

 

package com.yida.framework.lucene5.analyzer.synonym;

import java.io.IOException;
import java.util.Stack;

import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.util.AttributeSource;

/**
 * 自定义同义词过滤器
 * 
 * @author Lanxiaowei
 * 
 */
public class SynonymFilter extends TokenFilter {
	public static final String TOKEN_TYPE_SYNONYM = "SYNONYM";

	private Stack synonymStack;
	private SynonymEngine engine;
	private AttributeSource.State current;

	private final CharTermAttribute termAtt;
	private final PositionIncrementAttribute posIncrAtt;

	public SynonymFilter(TokenStream in, SynonymEngine engine) {
		super(in);
		synonymStack = new Stack(); // #1
		this.engine = engine;

		this.termAtt = addAttribute(CharTermAttribute.class);
		this.posIncrAtt = addAttribute(PositionIncrementAttribute.class);
	}

	public boolean incrementToken() throws IOException {
		if (synonymStack.size() > 0) { // #2
			String syn = synonymStack.pop(); // #2
			restoreState(current); // #2
			// 这里Lucene4.x的写法
			// termAtt.setTermBuffer(syn);

			// 这是Lucene5.x的写法
			termAtt.copyBuffer(syn.toCharArray(), 0, syn.length());
			posIncrAtt.setPositionIncrement(0); // #3
			return true;
		}

		if (!input.incrementToken()) // #4
			return false;

		if (addAliasesToStack()) { // #5
			current = captureState(); // #6
		}

		return true; // #7
	}

	private boolean addAliasesToStack() throws IOException {
		// 这里Lucene4.x的写法
		// String[] synonyms = engine.getSynonyms(termAtt.term()); //#8

		// 这里Lucene5.x的写法
		String[] synonyms = engine.getSynonyms(termAtt.toString()); // #8

		if (synonyms == null) {
			return false;
		}
		for (String synonym : synonyms) { // #9
			synonymStack.push(synonym);
		}
		return true;
	}
}

/*
#1 Define synonym buffer
#2 Pop buffered synonyms
#3 Set position increment to 0
#4 Read next token
#5 Push synonyms onto stack
#6 Save current token
#7 Return current token
#8 Retrieve synonyms
#9 Push synonyms onto stack
*/

 

package com.yida.framework.lucene5.analyzer.synonym;

import java.io.BufferedReader;
import java.io.Reader;
import java.io.StringReader;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.Analyzer.TokenStreamComponents;
import org.apache.lucene.analysis.core.LetterTokenizer;
import org.apache.lucene.analysis.core.LowerCaseFilter;
import org.apache.lucene.analysis.core.StopAnalyzer;
import org.apache.lucene.analysis.core.StopFilter;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;

import com.yida.framework.lucene5.util.analyzer.codec.MetaphoneReplacementFilter;

/**
 * 自定义同义词分词器
 * 
 * @author Lanxiaowei
 * @createTime 2015-03-31 10:15:23
 */
public class SynonymAnalyzer extends Analyzer {

	private SynonymEngine engine;

	public SynonymAnalyzer(SynonymEngine engine) {
		this.engine = engine;
	}

	@Override
	protected TokenStreamComponents createComponents(String text) {
		Tokenizer tokenizer = new StandardTokenizer();
		TokenStream tokenStream = new SynonymFilter(tokenizer, engine);
		tokenStream = new LowerCaseFilter(tokenStream);
		tokenStream = new StopFilter(tokenStream,StopAnalyzer.ENGLISH_STOP_WORDS_SET);
		return new TokenStreamComponents(tokenizer, tokenStream);
	}
}

 

package com.yida.framework.lucene5.analyzer.synonym;

import java.io.IOException;

import org.apache.lucene.analysis.Analyzer;

import com.yida.framework.lucene5.util.AnalyzerUtils;

public class SynonymAnalyzerTest {
	public static void main(String[] args) throws IOException {
		String text = "The quick brown fox jumps over the lazy dog";
	    Analyzer analyzer = new SynonymAnalyzer(new BaseSynonymEngine());
		AnalyzerUtils.displayTokens(analyzer, text);
	}
}

 

package com.yida.framework.lucene5.util;

import java.io.IOException;

import junit.framework.Assert;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.analysis.tokenattributes.TypeAttribute;

/**
 * 用于分词器测试的一个简单工具类(用于打印分词情况，包括Term的起始位置和结束位置(即所谓的偏 * 移量)，位置增量，Term字符串，Term字符串类型(字符串/阿拉伯数字之类的))
 * @author Lanxiaowei
 *
 */
public class AnalyzerUtils {
	public static void displayTokens(Analyzer analyzer,String text) throws IOException {
		TokenStream tokenStream = analyzer.tokenStream("text", text);
		displayTokens(tokenStream);
	}
	
	public static void displayTokens(TokenStream tokenStream) throws IOException {
		OffsetAttribute offsetAttribute = tokenStream.addAttribute(OffsetAttribute.class);
		PositionIncrementAttribute positionIncrementAttribute = tokenStream.addAttribute(PositionIncrementAttribute.class);
		CharTermAttribute charTermAttribute = tokenStream.addAttribute(CharTermAttribute.class);
		TypeAttribute typeAttribute = tokenStream.addAttribute(TypeAttribute.class);
		
		tokenStream.reset();
		int position = 0;
		while (tokenStream.incrementToken()) {
			int increment = positionIncrementAttribute.getPositionIncrement();
			if(increment > 0) {
				position = position + increment;
				System.out.print(position + ":");
			}
		    int startOffset = offsetAttribute.startOffset();
		    int endOffset = offsetAttribute.endOffset();
		    String term = charTermAttribute.toString();
		    System.out.println("[" + term + "]" + ":(" + startOffset + "-->" + endOffset + "):" + typeAttribute.type());
		}
	}
	
	/**
	 * 断言分词结果
	 * @param analyzer
	 * @param text        源字符串
	 * @param expecteds   期望分词后结果
	 * @throws IOException 
	 */
	public static void assertAnalyzerTo(Analyzer analyzer,String text,String[] expecteds) throws IOException {
		TokenStream tokenStream = analyzer.tokenStream("text", text);
		CharTermAttribute charTermAttribute = tokenStream.addAttribute(CharTermAttribute.class);
		for(String expected : expecteds) {
			Assert.assertTrue(tokenStream.incrementToken());
			Assert.assertEquals(expected, charTermAttribute.toString());
		}
		Assert.assertFalse(tokenStream.incrementToken());
		tokenStream.close();
	}
}

 以上代码都是Lucene in Action这本书里面的示例代码，我只不过是基于Lucene5.x把它重写并调试成功了，特此分享，希望对正在学习Lucene5的童鞋们有所帮助。demo代码我会在底下附件里上传，有需要demo源码的请自己在底下的附件里下载，Lucene in Action这本书的随书源码我已上传到我的百度网盘，也一并分享给大家，Lucene in Action随书源码百度网盘下载地址：

       戳我，戳我，快戳我！！！Come on.

      

      千言万语都在代码中，就不多说了，打完收工！

 

 

如果你还有什么问题请加我Ｑ-Q：7-3-6-0-3-1-3-0-5，

或者加裙
一起交流学习！

 

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