org.emau.icmvc.ganimed.deduplication.impl.LevenshteinBlockingAlgorithm.java Source code

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Here is the source code for org.emau.icmvc.ganimed.deduplication.impl.LevenshteinBlockingAlgorithm.java

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package org.emau.icmvc.ganimed.deduplication.impl;

/*
 * ###license-information-start###
 * E-PIX - Enterprise Patient Identifier Cross-referencing
 * __
 * Copyright (C) 2009 - 2017 The MOSAIC Project - Institut fuer Community Medicine der
 *                      Universitaetsmedizin Greifswald - mosaic-projekt@uni-greifswald.de
 *                      concept and implementation
 *                      c. schack, d.langner, l. geidel
 *                      web client
 *                      a. blumentritt
 *                      g. weiher
 *                      please cite our publications
 *                      http://dx.doi.org/10.3414/ME14-01-0133
 *                      http://dx.doi.org/10.1186/s12967-015-0545-6
 * __
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * ###license-information-end###
 */

import org.apache.log4j.Logger;
import org.emau.icmvc.ganimed.deduplication.BlockingMatchingAlgorithm;
import org.emau.icmvc.ganimed.exception.DeduplicationException;

import com.google.gwt.dev.util.editdistance.ModifiedBerghelRoachEditDistance;

public class LevenshteinBlockingAlgorithm<T> implements BlockingMatchingAlgorithm<T> {

    protected static final Logger logger = Logger.getLogger(LevenshteinBlockingAlgorithm.class);

    @Override
    public float block(String str1, String str2) throws DeduplicationException {

        if (str1 == null || str2 == null) {
            throw new IllegalArgumentException("Strings must not be null");
        }

        //choose longest string
        int length = str1.length() >= str2.length() ? str1.length() : str2.length();
        ModifiedBerghelRoachEditDistance brInstance = ModifiedBerghelRoachEditDistance.getInstance(str1);
        float r = (float) (length > 0 ? 1 - brInstance.getDistance(str2, length) / (float) length : 1.0);
        if (logger.isTraceEnabled()) {
            logger.trace("Levenshtein distance for blogging " + str1 + " and " + str2 + " = " + r);
        }

        return r;
    }
}