org.apache.avalon.framework

Class Version

Implemented Interfaces:
Comparable, Serializable

public final class Version
extends java.lang.Object
implements Comparable, Serializable

This class is used to hold version information pertaining to a Component or interface.

The version number of a Component is made up of three dot-separated fields:

"major.minor.micro"

The major, minor and micro fields are integer numbers represented in decimal notation and have the following meaning:

Version:
CVS $Revision: 1.33 $ $Date: 2004/02/11 14:34:24 $
Author:
Avalon Development Team

Constructor Summary

Version(int major, int minor, int micro)
Create a new instance of a Version object with the specified version numbers.

Method Summary

int
compareTo(Object o)
Compare two versions together according to the Comparable interface.
boolean
complies(Version other)
Check this Version against another for compliancy (compatibility).
boolean
equals(Object other)
Indicates whether some other object is "equal to" this Version.
boolean
equals(Version other)
Check this Version against another for equality.
int
getMajor()
Retrieve major component of version.
int
getMicro()
Retrieve micro component of version.
int
getMinor()
Retrieve minor component of version.
static Version
getVersion(String version)
Parse a version out of a string.
int
hashCode()
Add a hashing function to ensure the Version object is treated as expected in hashmaps and sets.
String
toString()
Overload toString to report version correctly.

Constructor Details

Version

public Version(int major,
               int minor,
               int micro)
Create a new instance of a Version object with the specified version numbers.
Parameters:
major - This Version major number.
minor - This Version minor number.
micro - This Version micro number.

Method Details

compareTo

public int compareTo(Object o)
Compare two versions together according to the Comparable interface.
Returns:
number indicating relative value (-1, 0, 1)

complies

public boolean complies(Version other)
Check this Version against another for compliancy (compatibility).

If this Version is compatible with the specified one, then true is returned, otherwise false. Be careful when using this method since, in example, version 1.3.7 is compliant to version 1.3.6, while the opposite is not.

The following example displays the expected behaviour and results of version.

 final Version v1 = new Version( 1, 3 , 6 );
 final Version v2 = new Version( 1, 3 , 7 );
 final Version v3 = new Version( 1, 4 , 0 );
 final Version v4 = new Version( 2, 0 , 1 );

 assert(   v1.complies( v1 ) );
 assert( ! v1.complies( v2 ) );
 assert(   v2.complies( v1 ) );
 assert( ! v1.complies( v3 ) );
 assert(   v3.complies( v1 ) );
 assert( ! v1.complies( v4 ) );
 assert( ! v4.complies( v1 ) );
 
Parameters:
other - The other Version object to be compared with this for compliancy (compatibility).
Returns:
true if this Version is compatible with the specified one

equals

public boolean equals(Object other)
Indicates whether some other object is "equal to" this Version. Returns true if the other object is an instance of Version and has the same major, minor, and micro components.
Parameters:
other - an Object value
Returns:
true if the other object is equal to this Version

equals

public boolean equals(Version other)
Check this Version against another for equality.

If this Version is compatible with the specified one, then true is returned, otherwise false.

Parameters:
other - The other Version object to be compared with this for equality.
Returns:
true if this Version is compatible with the specified one
Since:
4.1

getMajor

public int getMajor()
Retrieve major component of version.
Returns:
the major component of version
Since:
4.1

getMicro

public int getMicro()
Retrieve micro component of version.
Returns:
the micro component of version.
Since:
4.1

getMinor

public int getMinor()
Retrieve minor component of version.
Returns:
the minor component of version
Since:
4.1

getVersion

public static Version getVersion(String version)
            throws NumberFormatException,
                   IllegalArgumentException
Parse a version out of a string. The version string format is .. where both minor and micro are optional.
Parameters:
version - The input version string
Returns:
the new Version object
Since:
4.1

hashCode

public int hashCode()
Add a hashing function to ensure the Version object is treated as expected in hashmaps and sets. NOTE: any time the equals() is overridden, hashCode() should also be overridden.
Returns:
the hashCode

toString

public String toString()
Overload toString to report version correctly.
Returns:
the dot seperated version string