/*
* Copyright (c) OSGi Alliance (2004, 2012). All Rights Reserved.
*
* Licensed 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 org.osgi.framework;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
/**
* Version identifier for capabilities such as bundles and packages.
* <p>
* Version identifiers have four components.
* <ol>
* <li>Major version. A non-negative integer.</li>
* <li>Minor version. A non-negative integer.</li>
* <li>Micro version. A non-negative integer.</li>
* <li>Qualifier. A text string. See {@code Version(String)} for the format of the qualifier string.
* </li>
* </ol>
* <p>
* {@code Version} objects are immutable.
*
* @since 1.3
* @Immutable
* @version $Id: a0b5a865f7fbf2b3dcb77a13b2e99da0b64702bb $
*/
public class Version implements Comparable<Version> {
/**
* Parses a version identifier from the specified string.
* <p>
* See {@code Version(String)} for the format of the version string.
*
* @param version String representation of the version identifier. Leading and trailing whitespace
* will be ignored.
* @return A {@code Version} object representing the version identifier. If {@code version} is
* {@code null} or the empty string then {@code emptyVersion} will be returned.
* @throws IllegalArgumentException If {@code version} is improperly formatted.
*/
public static Version parseVersion(String version) {
if (version == null) {
return emptyVersion;
}
version = version.trim();
if (version.length() == 0) {
return emptyVersion;
}
return new Version(version);
}
/**
* Parse numeric component into an int.
*
* @param value Numeric component
* @param version Complete version string for exception message, if any
* @return int value of numeric component
*/
private static int parseInt(String value, String version) {
try {
return Integer.parseInt(value);
} catch (NumberFormatException e) {
IllegalArgumentException iae = new IllegalArgumentException("invalid version \"" + version
+ "\": non-numeric \"" + value + "\"");
iae.initCause(e);
throw iae;
}
}
private final int major;
private final int minor;
private final int micro;
private final String qualifier;
private static final String SEPARATOR = ".";
private transient String versionString /* default to null */;
private transient int hash /* default to 0 */;
/**
* The empty version "0.0.0".
*/
public static final Version emptyVersion = new Version(0, 0, 0);
/**
* Creates a version identifier from the specified numerical components.
* <p>
* The qualifier is set to the empty string.
*
* @param major Major component of the version identifier.
* @param minor Minor component of the version identifier.
* @param micro Micro component of the version identifier.
* @throws IllegalArgumentException If the numerical components are negative.
*/
public Version(int major, int minor, int micro) {
this(major, minor, micro, null);
}
/**
* Creates a version identifier from the specified components.
*
* @param major Major component of the version identifier.
* @param minor Minor component of the version identifier.
* @param micro Micro component of the version identifier.
* @param qualifier Qualifier component of the version identifier. If {@code null} is specified,
* then the qualifier will be set to the empty string.
* @throws IllegalArgumentException If the numerical components are negative or the qualifier
* string is invalid.
*/
public Version(int major, int minor, int micro, String qualifier) {
if (qualifier == null) {
qualifier = "";
}
this.major = major;
this.minor = minor;
this.micro = micro;
this.qualifier = qualifier;
validate();
}
/**
* Creates a version identifier from the specified string.
* <p>
* Version string grammar:
*
* <pre>
* version ::= major('.'minor('.'micro('.'qualifier)?)?)?
* major ::= digit+
* minor ::= digit+
* micro ::= digit+
* qualifier ::= (alpha|digit|'_'|'-')+
* digit ::= [0..9]
* alpha ::= [a..zA..Z]
* </pre>
*
* @param version String representation of the version identifier. There must be no whitespace in
* the argument.
* @throws IllegalArgumentException If {@code version} is improperly formatted.
*/
public Version(String version) {
int maj = 0;
int min = 0;
int mic = 0;
String qual = "";
try {
StringTokenizer st = new StringTokenizer(version, SEPARATOR, true);
maj = parseInt(st.nextToken(), version);
if (st.hasMoreTokens()) { // minor
st.nextToken(); // consume delimiter
min = parseInt(st.nextToken(), version);
if (st.hasMoreTokens()) { // micro
st.nextToken(); // consume delimiter
mic = parseInt(st.nextToken(), version);
if (st.hasMoreTokens()) { // qualifier separator
st.nextToken(); // consume delimiter
qual = st.nextToken(""); // remaining string
if (st.hasMoreTokens()) { // fail safe
throw new IllegalArgumentException("invalid version \"" + version
+ "\": invalid format");
}
}
}
}
} catch (NoSuchElementException e) {
IllegalArgumentException iae = new IllegalArgumentException("invalid version \"" + version
+ "\": invalid format");
iae.initCause(e);
throw iae;
}
major = maj;
minor = min;
micro = mic;
qualifier = qual;
validate();
}
/**
* Compares this {@code Version} object to another {@code Version}.
* <p>
* A version is considered to be <b>less than</b> another version if its major component is less
* than the other version's major component, or the major components are equal and its minor
* component is less than the other version's minor component, or the major and minor components
* are equal and its micro component is less than the other version's micro component, or the
* major, minor and micro components are equal and it's qualifier component is less than the other
* version's qualifier component (using {@code String.compareTo}).
* <p>
* A version is considered to be <b>equal to</b> another version if the major, minor and micro
* components are equal and the qualifier component is equal (using {@code String.compareTo}).
*
* @param other The {@code Version} object to be compared.
* @return A negative integer, zero, or a positive integer if this version is less than, equal to,
* or greater than the specified {@code Version} object.
* @throws ClassCastException If the specified object is not a {@code Version} object.
*/
@Override
public int compareTo(Version other) {
if (other == this) { // quicktest
return 0;
}
int result = major - other.major;
if (result != 0) {
return result;
}
result = minor - other.minor;
if (result != 0) {
return result;
}
result = micro - other.micro;
if (result != 0) {
return result;
}
return qualifier.compareTo(other.qualifier);
}
/**
* Compares this {@code Version} object to another object.
* <p>
* A version is considered to be <b>equal to </b> another version if the major, minor and micro
* components are equal and the qualifier component is equal (using {@code String.equals}).
*
* @param object The {@code Version} object to be compared.
* @return {@code true} if {@code object} is a {@code Version} and is equal to this object;
* {@code false} otherwise.
*/
@Override
public boolean equals(Object object) {
if (object == this) { // quicktest
return true;
}
if (!(object instanceof Version)) {
return false;
}
Version other = (Version) object;
return (major == other.major) && (minor == other.minor) && (micro == other.micro)
&& qualifier.equals(other.qualifier);
}
/**
* Returns the major component of this version identifier.
*
* @return The major component.
*/
public int getMajor() {
return major;
}
/**
* Returns the micro component of this version identifier.
*
* @return The micro component.
*/
public int getMicro() {
return micro;
}
/**
* Returns the minor component of this version identifier.
*
* @return The minor component.
*/
public int getMinor() {
return minor;
}
/**
* Returns the qualifier component of this version identifier.
*
* @return The qualifier component.
*/
public String getQualifier() {
return qualifier;
}
/**
* Returns a hash code value for the object.
*
* @return An integer which is a hash code value for this object.
*/
@Override
public int hashCode() {
if (hash != 0) {
return hash;
}
int h = 31 * 17;
h = 31 * h + major;
h = 31 * h + minor;
h = 31 * h + micro;
h = 31 * h + qualifier.hashCode();
return hash = h;
}
/**
* Returns the string representation of this version identifier.
* <p>
* The format of the version string will be {@code major.minor.micro} if qualifier is the empty
* string or {@code major.minor.micro.qualifier} otherwise.
*
* @return The string representation of this version identifier.
*/
@Override
public String toString() {
return toString0();
}
/**
* Internal toString behavior
*
* @return The string representation of this version identifier.
*/
String toString0() {
if (versionString != null) {
return versionString;
}
int q = qualifier.length();
StringBuffer result = new StringBuffer(20 + q);
result.append(major);
result.append(SEPARATOR);
result.append(minor);
result.append(SEPARATOR);
result.append(micro);
if (q > 0) {
result.append(SEPARATOR);
result.append(qualifier);
}
return versionString = result.toString();
}
/**
* Called by the Version constructors to validate the version components.
*
* @throws IllegalArgumentException If the numerical components are negative or the qualifier
* string is invalid.
*/
private void validate() {
if (major < 0) {
throw new IllegalArgumentException("invalid version \"" + toString0()
+ "\": negative number \"" + major + "\"");
}
if (minor < 0) {
throw new IllegalArgumentException("invalid version \"" + toString0()
+ "\": negative number \"" + minor + "\"");
}
if (micro < 0) {
throw new IllegalArgumentException("invalid version \"" + toString0()
+ "\": negative number \"" + micro + "\"");
}
for (char ch : qualifier.toCharArray()) {
if (('A' <= ch) && (ch <= 'Z')) {
continue;
}
if (('a' <= ch) && (ch <= 'z')) {
continue;
}
if (('0' <= ch) && (ch <= '9')) {
continue;
}
if ((ch == '_') || (ch == '-')) {
continue;
}
throw new IllegalArgumentException("invalid version \"" + toString0()
+ "\": invalid qualifier \"" + qualifier + "\"");
}
}
}