/*
* 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.
*/
package com.skcraft.launcher.selfupdate;
import java.util.*;
/**
* Generic implementation of version comparison.
* <p/>
* NOTE: This class is a copy of r658725 of http://svn.apache.org/repos/asf/maven/artifact/trunk/src/main/java/org/apache/maven/artifact/versioning/ComparableVersion.java.
*
* @author <a href="mailto:kenney@apache.org">Kenney Westerhof</a>
* @author <a href="mailto:hboutemy@apache.org">Herve Boutemy</a>
* @version $Id$
*/
@SuppressWarnings("unchecked")
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 Integer value;
public IntegerItem(Integer i) {
this.value = i;
}
public int getType() {
return INTEGER_ITEM;
}
public boolean isNull() {
return (value == 0);
}
public int compareTo(Item item) {
if (item == null) {
return value == 0 ? 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.
* <p/>
* This method both takes into account the ordering of known qualifiers as well as lexical ordering for unknown
* qualifiers.
* <p/>
* 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() {
StringBuffer buffer = new StringBuffer("(");
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(new IntegerItem(0));
} else {
list.add(parseItem(isDigit, version.substring(startIndex, i)));
}
startIndex = i + 1;
} else if (c == '-') {
if (i == startIndex) {
list.add(new IntegerItem(0));
} 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 ? new IntegerItem(new Integer(buf)) : 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();
}
}