VersionNumber.java :  » Content-Management-System » contelligent » de » finix » contelligent » core » Java Open Source

/*
 * Copyright 2001-2006 C:1 Financial Services GmbH
 *
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License Version 2.1, as published by the Free Software Foundation.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
 */

package de.finix.contelligent.core;

import java.util.ArrayList;
import java.util.StringTokenizer;

/**
 * This class represents a version number in the form of Major.Minor.Patch. This
 * is used to compare package version numbers.
 */
public class VersionNumber implements Comparable {

    public VersionNumber(String number) throws IllegalArgumentException {
        version = parse(number);
    }

    public int getMajor() {
        return version[0];
    }

    public int getMinor() {
        if (version.length == 1) {
            return 0;
        }
        return version[1];
    }

    public int getPatch() {
        if (version.length == 2) {
            return 0;
        }
        return version[2];
    }

    protected int[] parse(String number) throws IllegalArgumentException {
        StringTokenizer tokenizer = new StringTokenizer(number, ".");
        ArrayList tmp = new ArrayList(3);

        while (tokenizer.hasMoreTokens()) {
            String token = tokenizer.nextToken();
            try {
                tmp.add(new Integer(token));
            } catch (NumberFormatException e) {
                throw new IllegalArgumentException("'" + number + "' is not a valid version number");
            }
        }
        if ((tmp.size() > 3) || (tmp.size() == 0)) {
            throw new IllegalArgumentException("'" + number + "' is not a valid version number");
        }
        int[] answer = new int[tmp.size()];

        for (int i = 0; i < tmp.size(); i++) {
            answer[i] = ((Integer) tmp.get(i)).intValue();
        }
        return answer;
    }

    public int compareTo(Object object) {
        VersionNumber other = (VersionNumber) object;

        // compare major
        if (getMajor() < other.getMajor()) {
            return -1;
        }
        if (getMajor() > other.getMajor()) {
            return 1;
        }
        // equal major numbers --> compare minor
        if (getMinor() < other.getMinor()) {
            return -1;
        }
        if (getMinor() > other.getMinor()) {
            return 1;
        }
        // equal major and minor numbers --> compare patch
        if (getPatch() < other.getPatch()) {
            return -1;
        }
        if (getPatch() > other.getPatch()) {
            return 1;
        }
        // we are equal
        return 0;
    }

    public String toString() {
        return getMajor() + "." + getMinor() + "." + getPatch();
    }

    public boolean equals(Object obj) {
        return compareTo(obj) == 0;
    }

    private int[] version;
}