package org.hotswap.agent.versions;
/*
* 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.Locale;
import java.util.Properties;
import java.util.Stack;
/**
* Generic implementation of version comparison.
*
* <p>
* Features:
* <ul>
* <li>mixing of '<code>-</code>' (dash) and '<code>.</code>' (dot) separators,
* </li>
* <li>transition between characters and digits also constitutes a separator:
* <code>1.0alpha1 => [1, 0, alpha, 1]</code></li>
* <li>unlimited number of version components,</li>
* <li>version components in the text can be digits or strings,</li>
* <li>strings are checked for well-known qualifiers and the qualifier ordering
* is used for version ordering. Well-known qualifiers (case insensitive) are:
* <ul>
* <li><code>alpha</code> or <code>a</code></li>
* <li><code>beta</code> or <code>b</code></li>
* <li><code>milestone</code> or <code>m</code></li>
* <li><code>rc</code> or <code>cr</code></li>
* <li><code>snapshot</code></li>
* <li><code>(the empty string)</code> or <code>ga</code> or <code>final</code>
* </li>
* <li><code>sp</code></li>
* </ul>
* Unknown qualifiers are considered after known qualifiers, with lexical order
* (always case insensitive),</li>
* <li>a dash usually precedes a qualifier, and is always less important than
* something preceded with a dot.</li>
* </ul>
* </p>
*
* @author <a href="mailto:kenney@apache.org">Kenney Westerhof</a>
* @author <a href="mailto:hboutemy@apache.org">Hervé Boutemy</a>
* @see <a href=
* "https://cwiki.apache.org/confluence/display/MAVENOLD/Versioning">
* "Versioning" on Maven Wiki</a>
*/
public class ComparableVersion implements Comparable<ComparableVersion> {
/** The value. */
private String value;
/** The canonical. */
private String canonical;
/** The items. */
private ListItem items;
/**
* The Interface Item.
*/
private interface Item {
/** The integer item. */
int INTEGER_ITEM = 0;
/** The string item. */
int STRING_ITEM = 1;
/** The list item. */
int LIST_ITEM = 2;
/**
* Compare to.
*
* @param item the item
* @return the int
*/
int compareTo(Item item);
/**
* Gets the type.
*
* @return the type
*/
int getType();
/**
* Checks if is null.
*
* @return true, if is null
*/
boolean isNull();
}
/**
* Represents a numeric item in the version item list.
*/
private static class IntegerItem implements Item {
/** The Constant BIG_INTEGER_ZERO. */
private static final BigInteger BIG_INTEGER_ZERO = new BigInteger("0");
/** The value. */
private final BigInteger value;
/** The Constant ZERO. */
public static final IntegerItem ZERO = new IntegerItem();
/**
* Instantiates a new integer item.
*/
private IntegerItem() {
this.value = BIG_INTEGER_ZERO;
}
/**
* Instantiates a new integer item.
*
* @param str the str
*/
public IntegerItem(String str) {
this.value = new BigInteger(str);
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#getType()
*/
public int getType() {
return INTEGER_ITEM;
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#isNull()
*/
public boolean isNull() {
return BIG_INTEGER_ZERO.equals(value);
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#compareTo(org.hotswap.agent.versions.ComparableVersion.Item)
*/
public int compareTo(Item item) {
if (item == null) {
return BIG_INTEGER_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());
}
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString() {
return value.toString();
}
}
/**
* Represents a string in the version item list, usually a qualifier.
*/
private static class StringItem implements Item {
/** The Constant QUALIFIERS. */
private static final String[] QUALIFIERS = { "alpha", "beta", "milestone", "rc", "snapshot", "", "sp" };
/** The Constant AR_QUALIFIERS. */
private static final List<String> AR_QUALIFIERS = Arrays.asList(QUALIFIERS);
/** The Constant ALIASES. */
private static final Properties ALIASES = new Properties();
static {
ALIASES.put("ga", "");
ALIASES.put("final", "");
ALIASES.put("cr", "rc");
}
/**
* A comparable value 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 final String RELEASE_VERSION_INDEX = String.valueOf(AR_QUALIFIERS.indexOf(""));
/** The value. */
private String value;
/**
* Instantiates a new string item.
*
* @param value the value
* @param followedByDigit the followed by digit
*/
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;
default:
}
}
this.value = ALIASES.getProperty(value, value);
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#getType()
*/
public int getType() {
return STRING_ITEM;
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#isNull()
*/
public boolean isNull() {
return (comparableQualifier(value).compareTo(RELEASE_VERSION_INDEX) == 0);
}
/**
* Returns a comparable value for a qualifier.
*
* This method takes into account the ordering of known qualifiers then
* unknown qualifiers with lexical ordering.
*
* 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 the qualifier
* @return an equivalent value that can be used with lexical comparison
*/
public static String comparableQualifier(String qualifier) {
int i = AR_QUALIFIERS.indexOf(qualifier);
return i == -1 ? (AR_QUALIFIERS.size() + "-" + qualifier) : String.valueOf(i);
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#compareTo(org.hotswap.agent.versions.ComparableVersion.Item)
*/
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());
}
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
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<Item>implements Item {
/** The Constant serialVersionUID. */
private static final long serialVersionUID = 1L;
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#getType()
*/
public int getType() {
return LIST_ITEM;
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#isNull()
*/
public boolean isNull() {
return (size() == 0);
}
/**
* Normalize.
*/
void normalize() {
for (int i = size() - 1; i >= 0; i--) {
Item lastItem = get(i);
if (lastItem.isNull()) {
// remove null trailing items: 0, "", empty list
remove(i);
} else if (!(lastItem instanceof ListItem)) {
break;
}
}
}
/* (non-Javadoc)
* @see org.hotswap.agent.versions.ComparableVersion.Item#compareTo(org.hotswap.agent.versions.ComparableVersion.Item)
*/
public int compareTo(Item item) {
if (item == null) {
if (size() == 0) {
return 0; // 1-0 = 1- (normalize) = 1
}
Item first = 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<Item> left = iterator();
Iterator<Item> right = ((ListItem) item).iterator();
while (left.hasNext() || right.hasNext()) {
Item l = left.hasNext() ? left.next() : null;
Item r = right.hasNext() ? right.next() : null;
// if this is shorter, then invert the compare and mul with
// -1
int result = l == null ? (r == null ? 0 : -1 * r.compareTo(l)) : l.compareTo(r);
if (result != 0) {
return result;
}
}
return 0;
default:
throw new RuntimeException("invalid item: " + item.getClass());
}
}
/* (non-Javadoc)
* @see java.util.AbstractCollection#toString()
*/
public String toString() {
StringBuilder buffer = new StringBuilder();
for (Item item : this) {
if (buffer.length() > 0) {
buffer.append((item instanceof ListItem) ? '-' : '.');
}
buffer.append(item);
}
return buffer.toString();
}
}
/**
* Instantiates a new comparable version.
*
* @param version the version
*/
public ComparableVersion(String version) {
parseVersion(version);
}
/**
* Parses the version.
*
* @param version the version
*/
public final void parseVersion(String version) {
this.value = version;
items = new ListItem();
version = version.toLowerCase(Locale.ENGLISH);
ListItem list = items;
Stack<Item> 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;
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;
list.add(list = new ListItem());
stack.push(list);
}
isDigit = true;
} else {
if (isDigit && i > startIndex) {
list.add(parseItem(true, version.substring(startIndex, i)));
startIndex = i;
list.add(list = new ListItem());
stack.push(list);
}
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();
}
/**
* Parses the item.
*
* @param isDigit the is digit
* @param buf the buf
* @return the item
*/
private static Item parseItem(boolean isDigit, String buf) {
return isDigit ? new IntegerItem(buf) : new StringItem(buf, false);
}
/* (non-Javadoc)
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
public int compareTo(ComparableVersion o) {
return items.compareTo(o.items);
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString() {
return value;
}
/**
* Gets the canonical.
*
* @return the canonical
*/
public String getCanonical() {
return canonical;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equals(Object o) {
return (o instanceof ComparableVersion) && canonical.equals(ComparableVersion.class.cast(o).canonical);
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return canonical.hashCode();
}
/**
* Main to test version parsing and comparison.
*
* @param args
* the version strings to parse and compare
*/
public static void main(String... args) {
System.out.println("Display parameters as parsed by Maven (in canonical form) and comparison result:");
if (args.length == 0) {
return;
}
ComparableVersion prev = null;
int i = 1;
for (String version : args) {
ComparableVersion c = new ComparableVersion(version);
if (prev != null) {
int compare = prev.compareTo(c);
System.out.println(" " + prev.toString() + ' ' + ((compare == 0) ? "==" : ((compare < 0) ? "<" : ">")) + ' ' + version);
}
System.out.println(String.valueOf(i++) + ". " + version + " == " + c.getCanonical());
prev = c;
}
}
}