Package org.dellroad.stuff.string

Class VersionComparator

java.lang.Object

org.dellroad.stuff.string.VersionComparator

All Implemented Interfaces:

Comparator<String>

public class VersionComparator
extends Object
implements Comparator<String>

Comparator for version numbers.

Version numbers are broken up into parts, where a part is a contiguous sequence of one or more digits, or a contiguous sequence of one or more non-digits, and where the period character ('.') serves as a part separator. Then, parts are compared pair-wise until there is a difference, as determined by the Comparator provided to the constructor, or one version string runs out of parts, in which case it is less than the other.

Constructor Summary

Constructors

Constructor	Description
VersionComparator()	Convenience constructor.
VersionComparator(Comparator<String> partComparator)	Primary constructor.

Method Summary

Modifier and Type	Method	Description
int	compare(String v1, String v2)
protected List<String>	separateIntoParts(String version)	Split a version string into parts.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Details

VersionComparator

public VersionComparator(Comparator<String> partComparator)

Primary constructor.

Parameters:

partComparator - compares individual parts

Throws:

IllegalArgumentException - if partComparator is null

VersionComparator

public VersionComparator()

Convenience constructor.

Equivalent to VersionComparator(new VersionPartComparator()).

Method Details

compare

public int compare(String v1,
 String v2)

Specified by:

compare in interface Comparator<String>

separateIntoParts

protected List<String> separateIntoParts(String version)

Split a version string into parts.

The implementation in VersionComparator defines a part as a contiguous sequence of one or more digits, or a contiguous sequence of one or more non-digits, and where the period character ('.') serves as a part separator.

Subclasses may choose to override this method to define parts differently.

Parameters:

version - the original version string

Returns:

the parts of the version string