engine.easy.analyzer.EasySearchAnalyzer.java Source code

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Here is the source code for engine.easy.analyzer.EasySearchAnalyzer.java

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/*Copyright 2011 Deminem Solutions
    
Licensed 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.
*/

package engine.easy.analyzer;

/**
 * This is a EasySearchAnalyzer class which works on the same lucene proposed steps of analyzing the text.
 * The steps are involved to tokenize the text, remove stop words, stem English words, and transform the text into lowercase pattern.
 * 
 * Author: Adnan Urooj
 * 
 */
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.KeywordAnalyzer;
import org.apache.lucene.analysis.LowerCaseFilter;
import org.apache.lucene.analysis.LowerCaseTokenizer;
import org.apache.lucene.analysis.PorterStemFilter;
import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.analysis.StopAnalyzer;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;
import org.apache.lucene.util.Version;

import engine.easy.util.AppConstants;

public class EasySearchAnalyzer extends Analyzer {

    private final boolean enableStopPositionIncrements;

    public EasySearchAnalyzer() {
        // According to API, this below will preserve positions of the incoming tokens (ie, accumulate and set position increments of the removed tokens).
        enableStopPositionIncrements = StopFilter.getEnablePositionIncrementsVersionDefault(Version.LUCENE_30);
    }

    @Override
    public TokenStream tokenStream(String fieldName, Reader reader) {

        return new PorterStemFilter(new StopFilter(enableStopPositionIncrements,
                new LowerCaseFilter(new StandardFilter(new StandardTokenizer(Version.LUCENE_30, reader))),
                EasySearchStopAnalyzer.ENGLISH_STOP_WORDS_SET));
    }

    public static void testAnalyzer(String fileName, Analyzer analyzer, boolean compareWithLuceneAnaylzers)
            throws IOException {

        try {
            File file = new File(fileName);
            if (!file.exists()) {
                System.out.println("The specified data bank directory does not exist: " + file);
                System.exit(-1);
            }

            int ch;
            StringBuffer text = new StringBuffer("");
            FileInputStream fin = new FileInputStream(file);
            while ((ch = fin.read()) != -1)
                text.append((char) ch);
            fin.close();

            if (compareWithLuceneAnaylzers) {

                System.out.println("\n###### StandardAnalyzer !! ######");
                printResult(text.toString(), new StandardAnalyzer(Version.LUCENE_30));

                //            System.out.println("\n###### SimpleAnalyzer !! ######");
                //            printResult(text.toString(), new StandardAnalyzer());
                //            
                //            System.out.println("\n###### StopAnalyzer !! ######");
                //            printResult(text.toString(), new StandardAnalyzer());
                //            
                //            System.out.println("\n###### KeywordAnalyzer !! ######");
                //            printResult(text.toString(), new StandardAnalyzer());
                //            
                //            System.out.println("\n###### WhitespaceAnalyzer !! ######");
                //            printResult(text.toString(), new StandardAnalyzer());
                //            
                //            System.out.println("\n###### StopAnalyzer !! ######");
                //            printResult(text.toString(), new StandardAnalyzer());
            }

            System.out.println("\n###### EasySearchAnalyzer !! ######");
            printResult(text.toString(), new EasySearchAnalyzer());
        } catch (Exception e) {
            System.out.println("Exception : " + e.toString());
        }
    }

    private static void printResult(String text, Analyzer analyzer) throws IOException {

        int tokenCount = 0;
        TokenStream tokenStream = analyzer.tokenStream("FIELDNAME", new StringReader(text)); // this method will used for token streams
        TermAttribute termAtt = tokenStream.getAttribute(TermAttribute.class);
        while (tokenStream.incrementToken()) {
            tokenCount++;
            String tokenText = new String(termAtt.termBuffer(), 0, termAtt.termLength());
            System.out.println(" >> Token " + tokenCount + ": " + tokenText);
        }
    }

    public static void main(String args[]) {

        try {
            testAnalyzer(AppConstants.TXT_FILE, new EasySearchAnalyzer(), Boolean.TRUE);
        } catch (Exception e) {
            System.out.println("Exception : " + e.toString());
        }
    }
}