Java List Reverse compareVersions(List list1, List list2)

Description

INTERNAL: Compares two lists of Integers -1, 0, 1 means the first list is less than, equal, greater than the second list.

License

Open Source License

Declaration

static protected int compareVersions(List<Integer> list1,
        List<Integer> list2) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.//  w  ww  .  j  ava2s.  c o  m
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
 *     dminsky - added countOccurrencesOf(Object, List) API
 *     08/23/2010-2.2 Michael O'Brien
 *        - 323043: application.xml module ordering may cause weaving not to occur causing an NPE.
 *                       warn if expected "_persistence_*_vh" method not found
 *                       instead of throwing NPE during deploy validation.
 ******************************************************************************/

import java.util.ArrayList;

import java.util.List;

public class Main {
    /**
     * INTERNAL:
     * Compares two version in num.num.num.num.num*** format.
     * -1, 0, 1 means the version1 is less than, equal, greater than version2.
     * Example: compareVersions("11.1.0.6.0-Production", "11.1.0.7") == -1 
     * Example: compareVersions("WebLogic Server 10.3.4", "10.3.3.0") == 1
     */
    public static int compareVersions(String version1, String version2) {
        return compareVersions(version(version1), version(version2));
    }

    /**
     * INTERNAL:
     * Compares two lists of Integers
     * -1, 0, 1 means the first list is less than, equal, greater than the second list.
     * Example: {11, 1, 0, 6, 0} < {11, 1, 0, 7}
     */
    static protected int compareVersions(List<Integer> list1,
            List<Integer> list2) {
        int n = Math.max(list1.size(), list2.size());
        int res = 0;
        for (int i = 0; i < n; i++) {
            int l1 = 0;
            if (i < list1.size()) {
                l1 = list1.get(i);
            }
            int l2 = 0;
            if (i < list2.size()) {
                l2 = list2.get(i);
            }
            if (l1 < l2) {
                res = -1;
                break;
            } else if (l1 > l2) {
                res = 1;
                break;
            }
        }
        return res;
    }

    /**
     * INTERNAL:
     * Expects version in ***num.num.num.num.num*** format, converts it to a List of Integers.
     * Example: "11.1.0.6.0_Production" -> {11, 1, 0, 6, 0}
     * Example: "WebLogic Server 10.3.3.0" -> {10, 3, 3, 0}
     */
    static protected List<Integer> version(String version) {
        ArrayList<Integer> list = new ArrayList<Integer>(5);
        // first char - a digit - in the string corresponding to the current list index
        int iBegin = -1;
        // used to remove a non-digital prefix
        boolean isPrefix = true;
        for (int i = 0; i < version.length(); i++) {
            char ch = version.charAt(i);
            if ('0' <= ch && ch <= '9') {
                isPrefix = false;
                // it's a digit
                if (iBegin == -1) {
                    iBegin = i;
                }
            } else {
                // it's not a digit - try to create a number ending on the previous char - unless it's still part of the non-digital prefix.
                if (iBegin == -1) {
                    if (!isPrefix) {
                        break;
                    }
                } else {
                    isPrefix = false;
                    String strNum = version.substring(iBegin, i);
                    int num = Integer.parseInt(strNum, 10);
                    list.add(num);
                    iBegin = -1;
                    if (ch != '.') {
                        break;
                    }
                }
            }
        }
        if (iBegin >= 0) {
            String strNum = version.substring(iBegin, version.length());
            int num = Integer.parseInt(strNum, 10);
            list.add(num);
        }
        return list;
    }
}

Related

1. addReverse(List list, List append)
2. compareVersions(List version1, List version2)
3. compareVersions(String version1, String version2)
4. createReversedList(List inputList)
5. firstElementOf(List list, int reverseIndexPosition)