aos.lucene.search.msc.Explainer.java Source code

Introduction

Here is the source code for aos.lucene.search.msc.Explainer.java

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 * to you under the Apache License, Version 2.0 (the            *
 * "License"); you may not use this file except in compliance   *
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package aos.lucene.search.msc;

import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.Version;

import java.io.File;

// From chapter 3
public class Explainer {
    public static void main(String[] args) throws Exception {
        if (args.length != 2) {
            System.err.println("Usage: Explainer <index dir> <query>");
            System.exit(1);
        }

        String indexDir = args[0];
        String queryExpression = args[1];

        Directory directory = FSDirectory.open(new File(indexDir));
        QueryParser parser = new QueryParser(Version.LUCENE_46, "contents", new SimpleAnalyzer());
        Query query = parser.parse(queryExpression);

        LOGGER.info("Query: " + queryExpression);

        IndexSearcher searcher = new IndexSearcher(directory);
        TopDocs topDocs = searcher.search(query, 10);

        for (ScoreDoc match : topDocs.scoreDocs) {
            Explanation explanation = searcher.explain(query, match.doc); //#A

            LOGGER.info("----------");
            Document doc = searcher.doc(match.doc);
            LOGGER.info(doc.get("title"));
            LOGGER.info(explanation.toString()); //#B
        }
        searcher.close();
        directory.close();
    }
}
/*
#A Generate Explanation
#B Output Explanation
*/