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org.codehaus.mojo.versions.ordering.ComparableVersion Maven / Gradle / Ivy

package org.codehaus.mojo.versions.ordering;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to you 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.
 */

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Locale;
import java.util.Properties;
import java.util.Stack;

/**
 * Generic implementation of version comparison.
 *
 * @author Kenney Westerhof
 * @author Herve Boutemy
 * @version $Id: ComparableVersion.java 720520 2008-11-25 16:07:14Z bentmann $
 */
public class ComparableVersion
    implements Comparable
{
    private String value;

    private String canonical;

    private ListItem items;

    private interface Item
    {
        public static final int INTEGER_ITEM = 0;

        public static final int STRING_ITEM = 1;

        public static final int LIST_ITEM = 2;

        public int compareTo( Item item );

        public int getType();

        public boolean isNull();
    }

    /**
     * Represents a numeric item in the version item list.
     */
    private static class IntegerItem
        implements Item
    {
        private static final BigInteger BigInteger_ZERO = new BigInteger( "0" );

        private final BigInteger value;

        public static final IntegerItem ZERO = new IntegerItem();

        private IntegerItem()
        {
            this.value = BigInteger_ZERO;
        }

        public IntegerItem( String str )
        {
            this.value = new BigInteger( str );
        }

        public int getType()
        {
            return INTEGER_ITEM;
        }

        public boolean isNull()
        {
            return BigInteger_ZERO.equals( value );
        }

        public int compareTo( Item item )
        {
            if ( item == null )
            {
                return BigInteger_ZERO.equals( value ) ? 0 : 1; // 1.0 == 1, 1.1 > 1
            }

            switch ( item.getType() )
            {
                case INTEGER_ITEM:
                    return value.compareTo( ( (IntegerItem) item ).value );

                case STRING_ITEM:
                    return 1; // 1.1 > 1-sp

                case LIST_ITEM:
                    return 1; // 1.1 > 1-1

                default:
                    throw new RuntimeException( "invalid item: " + item.getClass() );
            }
        }

        public String toString()
        {
            return value.toString();
        }
    }

    /**
     * Represents a string in the version item list, usually a qualifier.
     */
    private static class StringItem
        implements Item
    {
        private final static String[] QUALIFIERS = { "snapshot", "alpha", "beta", "milestone", "rc", "", "sp" };

        private final static List _QUALIFIERS = Arrays.asList( QUALIFIERS );

        private final static Properties ALIASES = new Properties();

        static
        {
            ALIASES.put( "ga", "" );
            ALIASES.put( "final", "" );
            ALIASES.put( "cr", "rc" );
        }

        /**
         * A comparable for the empty-string qualifier. This one is used to determine if a given qualifier makes the
         * version older than one without a qualifier, or more recent.
         */
        private static Comparable RELEASE_VERSION_INDEX = String.valueOf( _QUALIFIERS.indexOf( "" ) );

        private String value;

        public StringItem( String value, boolean followedByDigit )
        {
            if ( followedByDigit && value.length() == 1 )
            {
                // a1 = alpha-1, b1 = beta-1, m1 = milestone-1
                switch ( value.charAt( 0 ) )
                {
                    case 'a':
                        value = "alpha";
                        break;
                    case 'b':
                        value = "beta";
                        break;
                    case 'm':
                        value = "milestone";
                        break;
                }
            }
            this.value = ALIASES.getProperty( value, value );
        }

        public int getType()
        {
            return STRING_ITEM;
        }

        public boolean isNull()
        {
            return ( comparableQualifier( value ).compareTo( RELEASE_VERSION_INDEX ) == 0 );
        }

        /**
         * Returns a comparable for a qualifier.
         * 

* This method both takes into account the ordering of known qualifiers as well as lexical ordering for unknown * qualifiers. *

* just returning an Integer with the index here is faster, but requires a lot of if/then/else to check for -1 * or QUALIFIERS.size and then resort to lexical ordering. Most comparisons are decided by the first character, * so this is still fast. If more characters are needed then it requires a lexical sort anyway. * * @param qualifier * @return */ public static Comparable comparableQualifier( String qualifier ) { int i = _QUALIFIERS.indexOf( qualifier ); return i == -1 ? _QUALIFIERS.size() + "-" + qualifier : String.valueOf( i ); } public int compareTo( Item item ) { if ( item == null ) { // 1-rc < 1, 1-ga > 1 return comparableQualifier( value ).compareTo( RELEASE_VERSION_INDEX ); } switch ( item.getType() ) { case INTEGER_ITEM: return -1; // 1.any < 1.1 ? case STRING_ITEM: return comparableQualifier( value ).compareTo( comparableQualifier( ( (StringItem) item ).value ) ); case LIST_ITEM: return -1; // 1.any < 1-1 default: throw new RuntimeException( "invalid item: " + item.getClass() ); } } public String toString() { return value; } } /** * Represents a version list item. This class is used both for the global item list and for sub-lists (which start * with '-(number)' in the version specification). */ private static class ListItem extends ArrayList implements Item { public int getType() { return LIST_ITEM; } public boolean isNull() { return ( size() == 0 ); } void normalize() { for ( ListIterator iterator = listIterator( size() ); iterator.hasPrevious(); ) { Item item = (Item) iterator.previous(); if ( item.isNull() ) { iterator.remove(); // remove null trailing items: 0, "", empty list } else { break; } } } public int compareTo( Item item ) { if ( item == null ) { if ( size() == 0 ) { return 0; // 1-0 = 1- (normalize) = 1 } Item first = (Item) get( 0 ); return first.compareTo( null ); } switch ( item.getType() ) { case INTEGER_ITEM: return -1; // 1-1 < 1.0.x case STRING_ITEM: return 1; // 1-1 > 1-sp case LIST_ITEM: Iterator left = iterator(); Iterator right = ( (ListItem) item ).iterator(); while ( left.hasNext() || right.hasNext() ) { Item l = left.hasNext() ? (Item) left.next() : null; Item r = right.hasNext() ? (Item) right.next() : null; // if this is shorter, then invert the compare and mul with -1 int result = l == null ? -1 * r.compareTo( l ) : l.compareTo( r ); if ( result != 0 ) { return result; } } return 0; default: throw new RuntimeException( "invalid item: " + item.getClass() ); } } public String toString() { StringBuilder buffer = new StringBuilder( "(" ); for ( Iterator iter = iterator(); iter.hasNext(); ) { buffer.append( iter.next() ); if ( iter.hasNext() ) { buffer.append( ',' ); } } buffer.append( ')' ); return buffer.toString(); } } public ComparableVersion( String version ) { parseVersion( version ); } public final void parseVersion( String version ) { this.value = version; items = new ListItem(); version = version.toLowerCase( Locale.ENGLISH ); ListItem list = items; Stack stack = new Stack(); stack.push( list ); boolean isDigit = false; int startIndex = 0; for ( int i = 0; i < version.length(); i++ ) { char c = version.charAt( i ); if ( c == '.' ) { if ( i == startIndex ) { list.add( IntegerItem.ZERO ); } else { list.add( parseItem( isDigit, version.substring( startIndex, i ) ) ); } startIndex = i + 1; } else if ( c == '-' ) { if ( i == startIndex ) { list.add( IntegerItem.ZERO ); } else { list.add( parseItem( isDigit, version.substring( startIndex, i ) ) ); } startIndex = i + 1; if ( isDigit ) { list.normalize(); // 1.0-* = 1-* if ( ( i + 1 < version.length() ) && Character.isDigit( version.charAt( i + 1 ) ) ) { // new ListItem only if previous were digits and new char is a digit, // ie need to differentiate only 1.1 from 1-1 list.add( list = new ListItem() ); stack.push( list ); } } } else if ( Character.isDigit( c ) ) { if ( !isDigit && i > startIndex ) { list.add( new StringItem( version.substring( startIndex, i ), true ) ); startIndex = i; } isDigit = true; } else { if ( isDigit && i > startIndex ) { list.add( parseItem( true, version.substring( startIndex, i ) ) ); startIndex = i; } isDigit = false; } } if ( version.length() > startIndex ) { list.add( parseItem( isDigit, version.substring( startIndex ) ) ); } while ( !stack.isEmpty() ) { list = (ListItem) stack.pop(); list.normalize(); } canonical = items.toString(); } private static Item parseItem( boolean isDigit, String buf ) { return isDigit ? (Item) new IntegerItem( buf ) : (Item) new StringItem( buf, false ); } public int compareTo( Object o ) { return items.compareTo( ( (ComparableVersion) o ).items ); } public String toString() { return value; } public boolean equals( Object o ) { return ( o instanceof ComparableVersion ) && canonical.equals( ( (ComparableVersion) o ).canonical ); } public int hashCode() { return canonical.hashCode(); } }





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