com.globalsight.ling.lucene.HighFreqTerms.java Source code

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Here is the source code for com.globalsight.ling.lucene.HighFreqTerms.java

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/**
 *  Copyright 2009 Welocalize, Inc. 
 *  
 *  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 com.globalsight.ling.lucene;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001,2004 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Lucene" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache Lucene", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.io.File;

import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.store.SimpleFSDirectory;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.PriorityQueue;

/**
 * <code>HighFreqTerms</code> class extracts terms and their
 * frequencies out of an existing Lucene index.
 *
 * @version $Id: HighFreqTerms.java,v 1.2 2013/09/13 06:14:27 wayne Exp $
 */
public class HighFreqTerms {
    // The top numTerms will be displayed
    public static final int numTerms = 100;

    public static void main(String[] args) throws Exception {
        IndexReader reader = null;
        if (args.length == 1) {
            SimpleFSDirectory fsd = new SimpleFSDirectory(new File(args[0]));
            reader = DirectoryReader.open(fsd);
        } else {
            usage();
            System.exit(1);
        }

        TermInfoQueue tiq = new TermInfoQueue(numTerms);
        //TODO: IS field right?
        String field = IndexDocument.TEXT;
        Terms terms = reader.getTermVector(0, field);
        //TermEnum terms = reader.terms();
        TermsEnum termsEnum = terms.iterator(null);

        BytesRef next = null;

        while ((next = termsEnum.next()) != null) {
            tiq.insertWithOverflow(new TermInfo(new Term(field, termsEnum.term()), termsEnum.docFreq()));
        }

        while (tiq.size() != 0) {
            TermInfo termInfo = (TermInfo) tiq.pop();
            System.out.println(termInfo.term + " " + termInfo.docFreq);
        }

        reader.close();
    }

    private static void usage() {
        System.out.println("\n\n" + "java org.apache.lucene.misc.HighFreqTerms <index dir>\n\n");
    }
}

final class TermInfo {
    TermInfo(Term t, int df) {
        term = t;
        docFreq = df;
    }

    int docFreq;
    Term term;
}

final class TermInfoQueue extends PriorityQueue {
    TermInfoQueue(int size) {
        super(size);
    }

    protected final boolean lessThan(Object a, Object b) {
        TermInfo termInfoA = (TermInfo) a;
        TermInfo termInfoB = (TermInfo) b;

        return termInfoA.docFreq < termInfoB.docFreq;
    }
}