lab_mri.SearchEngine.java Source code

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Here is the source code for lab_mri.SearchEngine.java

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/*
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package lab_mri;

/**
 *
 * @author luigi
 */

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;

import org.apache.lucene.queryparser.classic.MultiFieldQueryParser;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.queryparser.classic.QueryParser;

import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

public class SearchEngine {

    private final File dir;

    private IndexWriter writer;

    public SearchEngine(File dir) {
        this.dir = dir;
    }

    public void open() throws IOException {
        IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, new CustomAnalyzer());
        config.setOpenMode(IndexWriterConfig.OpenMode.CREATE_OR_APPEND);
        writer = new IndexWriter(FSDirectory.open(dir), config);
    }

    public void close() throws IOException {
        if (writer != null) {
            writer.close();
        }
    }

    public void addDocument(Document doc) throws IOException {
        writer.addDocument(doc);
    }

    public List<SearchResult> search(String query, String[] fields, int n)
            throws IOException, ParseException, Exception {

        String eq = QueryParser.escape(query);
        QueryParser parser = new MultiFieldQueryParser(fields, new CustomAnalyzer());
        Query q = parser.parse(eq);
        IndexSearcher searcher = new IndexSearcher(DirectoryReader.open(FSDirectory.open(this.dir)));
        List<SearchResult> results = new ArrayList<>();
        TopDocs top = searcher.search(q, n);

        for (ScoreDoc doc : top.scoreDocs) {
            results.add(new SearchResult(searcher.doc(doc.doc).get("id"), doc.score));
        }
        return results;
    }

    /* WIP
    public List<SearchResult>  pseudo_rf(String query , String[] fields, int n)
    throws IOException, ParseException, Exception, NullPointerException
    {
        
    String eq = QueryParser.escape(query);
    QueryParser parser = new MultiFieldQueryParser(fields, new  CustomAnalyzer());
    Query q = parser.parse(eq);
    IndexSearcher searcher = new IndexSearcher(DirectoryReader.open(FSDirectory.open(this.dir)));
    List<SearchResult> results = new ArrayList<>();
    TopDocs top = searcher.search(q, n);
        
    RocchioExpander re;
    re = new RocchioExpander(new StandardAnalyzer(), "abst", (float)0.5,(float)0.5,0, 1399);
        
        
        
    for (ScoreDoc doc : top.scoreDocs)
    {
    results.add(new SearchResult(searcher.doc(doc.doc).get("id"), doc.score));
    }
    String new_query = re.expand(query,results).concat(" ").concat(query);
        
    return this.search(removeStopWords(new_query), fields, 30);
        
    }
    */

}