focusedCrawler.util.persistence.Searcher.java Source code

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Here is the source code for focusedCrawler.util.persistence.Searcher.java

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/*
############################################################################
##
## Copyright (C) 2006-2009 University of Utah. All rights reserved.
##
## This file is part of DeepPeep.
##
## This file may be used under the terms of the GNU General Public
## License version 2.0 as published by the Free Software Foundation
## and appearing in the file LICENSE.GPL included in the packaging of
## this file.  Please review the following to ensure GNU General Public
## Licensing requirements will be met:
## http://www.opensource.org/licenses/gpl-license.php
##
## If you are unsure which license is appropriate for your use (for
## instance, you are interested in developing a commercial derivative
## of DeepPeep), please contact us at deeppeep@sci.utah.edu.
##
## This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
## WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
##
############################################################################
*/
package focusedCrawler.util.persistence;

import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.TermEnum;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.KeywordAnalyzer;
import org.apache.lucene.analysis.SimpleAnalyzer;
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.queryParser.QueryParser;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;

import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;

/**
 * <p>Title: </p>
 *
 * <p>Description: </p>
 *
 * <p>Copyright: Copyright (c) 2007</p>
 *
 * <p>Company: </p>
 *
 * @author not attributable
 * @version 1.0
 */
public class Searcher {
    private File indexDir;

    public Searcher(String indexPath) {
        this.indexDir = new File(indexPath);
        if (!indexDir.isDirectory() || !indexDir.exists())
            try {
                throw new IOException(indexPath + " does not exist or is not a directory");
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

    }

    public String get(String key) throws Exception {
        //   System.out.println("indexDir: " + this.indexDir.getAbsolutePath());
        Directory fsDir = FSDirectory.open(indexDir);
        IndexSearcher is = new IndexSearcher(fsDir);
        ScoreDoc[] hits = search(this.indexDir, key, is);
        if (hits.length != 0) {
            Document hitDoc = is.doc(hits[0].doc);
            return hitDoc.get("value");
        } else {
            return null;
        }
    }

    public TermEnum listElements(String indexDir) throws IOException {
        try {
            Directory fsDir = FSDirectory.open(new File(indexDir));
            IndexSearcher is = new IndexSearcher(fsDir);
            IndexReader reader = is.getIndexReader();
            return reader.terms();
        } catch (java.io.FileNotFoundException ex) {
            return null;
        }
    }

    private static ScoreDoc[] search(File indexDir, String q, IndexSearcher is) throws Exception {
        Analyzer analyzer = new KeywordAnalyzer();
        QueryParser parser = new QueryParser(null, "key", analyzer);
        Query query = parser.parse(q);
        TopDocs topDocs = is.search(query, 20);
        ScoreDoc[] hits = topDocs.scoreDocs;
        return hits;
    }

    public static void main(String[] args) {
        try {
            Searcher searcher = new Searcher(args[0]);
            long t0 = System.currentTimeMillis();
            System.out.println(searcher.get(URLEncoder.encode((args[1]))));
            System.out.println(System.currentTimeMillis() - t0);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}