org.cryptomator.common.SemVerComparator.java Source code

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Here is the source code for org.cryptomator.common.SemVerComparator.java

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/*******************************************************************************
 * Copyright (c) 2016 Sebastian Stenzel and others.
 * This file is licensed under the terms of the MIT license.
 * See the LICENSE.txt file for more info.
 *
 * Contributors:
 *     Sebastian Stenzel - initial API and implementation
 *******************************************************************************/
package org.cryptomator.common;

import java.util.Comparator;

import org.apache.commons.lang3.StringUtils;

public class SemVerComparator implements Comparator<String> {

    @Override
    public int compare(String version1, String version2) {
        final String[] vComps1 = StringUtils.split(version1, '.');
        final String[] vComps2 = StringUtils.split(version2, '.');
        final int commonCompCount = Math.min(vComps1.length, vComps2.length);

        for (int i = 0; i < commonCompCount; i++) {
            int subversionComparisionResult = 0;
            try {
                final int v1 = Integer.parseInt(vComps1[i]);
                final int v2 = Integer.parseInt(vComps2[i]);
                subversionComparisionResult = v1 - v2;
            } catch (NumberFormatException ex) {
                // ok, lets compare this fragment lexicographically
                subversionComparisionResult = vComps1[i].compareTo(vComps2[i]);
            }
            if (subversionComparisionResult != 0) {
                return subversionComparisionResult;
            }
        }

        // all in common so far? longest version string wins:
        return vComps1.length - vComps2.length;
    }

}