Module java.base

Package java.lang

Class Runtime.Version

java.lang.Object

java.lang.Runtime.Version

All Implemented Interfaces:

Comparable<Runtime.Version>

Enclosing class:

Runtime

public static class Runtime.Version
extends Object
implements Comparable<Runtime.Version>

A representation of a version string for an implementation of the Java SE Platform. A version string contains a version number optionally followed by pre-release and build information.

Version numbers

A version number, $VNUM, is a non-empty sequence of elements separated by period characters (U+002E). An element is either zero, or a unsigned integer numeral without leading zeros. The final element in a version number must not be zero. The format is:

     ^[1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*$
 

The sequence may be of arbitrary length but the first three elements are assigned specific meanings, as follows:

     $MAJOR.$MINOR.$SECURITY
 

• $MAJOR --- The major version number, incremented for a major release that contains significant new features as specified in a new edition of the Java SE Platform Specification, e.g., JSR 337 for Java SE 8. Features may be removed in a major release, given advance notice at least one major release ahead of time, and incompatible changes may be made when justified. The $MAJOR version number of JDK 8 is 8; the $MAJOR version number of JDK 9 is 9. When $MAJOR is incremented, all subsequent elements are removed.

• $MINOR --- The minor version number, incremented for a minor update release that may contain compatible bug fixes, revisions to standard APIs mandated by a Maintenance Release of the relevant Platform Specification, and implementation features outside the scope of that Specification such as new JDK-specific APIs, additional service providers, new garbage collectors, and ports to new hardware architectures.

• $SECURITY --- The security level, incremented for a security update release that contains critical fixes including those necessary to improve security. $SECURITY is not reset when $MINOR is incremented. A higher value of $SECURITY for a given $MAJOR value, therefore, always indicates a more secure release, regardless of the value of $MINOR.

The fourth and later elements of a version number are free for use by downstream consumers of this code base. Such a consumer may, e.g., use the fourth element to identify patch releases which contain a small number of critical non-security fixes in addition to the security fixes in the corresponding security release.

The version number does not include trailing zero elements; i.e., $SECURITY is omitted if it has the value zero, and $MINOR is omitted if both $MINOR and $SECURITY have the value zero.

The sequence of numerals in a version number is compared to another such sequence in numerical, pointwise fashion; e.g., 9.9.1 is less than 9.10.3. If one sequence is shorter than another then the missing elements of the shorter sequence are considered to be less than the corresponding elements of the longer sequence; e.g., 9.1.2 is less than 9.1.2.1.

Version strings

A version string, $VSTR, consists of a version number $VNUM, as described above, optionally followed by pre-release and build information, in the format

     $VNUM(-$PRE)?(\+($BUILD)?(-$OPT)?)?
 

where:

• $PRE, matching ([a-zA-Z0-9]+) --- A pre-release identifier. Typically ea, for a potentially unstable early-access release under active development, or internal, for an internal developer build.

• $BUILD, matching (0|[1-9][0-9]*) --- The build number, incremented for each promoted build. $BUILD is reset to 1 when any portion of $VNUM is incremented.

• $OPT, matching ([-a-zA-Z0-9\.]+) --- Additional build information, if desired. In the case of an internal build this will often contain the date and time of the build.

A version number 10-ea matches $VNUM = "10" and $PRE = "ea". The version number 10+-ea matches $VNUM = "10" and $OPT = "ea".

When comparing two version strings, the value of $OPT, if present, may or may not be significant depending on the chosen comparison method. The comparison methods compareTo() and compareToIgnoreOptional() should be used consistently with the corresponding methods equals() and equalsIgnoreOptional().

A short version string, $SVSTR, often useful in less formal contexts, is a version number optionally followed by a pre-release identifier:

     $VNUM(-$PRE)?
 

Since:

9

Method Summary

Modifier and Type	Method	Description
Optional<Integer>	build()	Returns the build number.
int	compareTo(Runtime.Version ob)	Compares this version to another.
int	compareToIgnoreOptional(Runtime.Version ob)	Compares this version to another disregarding optional build information.
boolean	equals(Object ob)	Determines whether this Version is equal to another object.
boolean	equalsIgnoreOptional(Object ob)	Determines whether this Version is equal to another disregarding optional build information.
int	hashCode()	Returns the hash code of this version.
int	major()	Returns the major version number.
int	minor()	Returns the minor version number or zero if it was not set.
Optional<String>	optional()	Returns optional additional identifying build information.
static Runtime.Version	parse(String s)	Parses the given string as a valid version string containing a version number followed by pre-release and build information.
Optional<String>	pre()	Returns the optional pre-release information.
int	security()	Returns the security version number or zero if it was not set.
String	toString()	Returns a string representation of this version.
List<Integer>	version()	Returns an unmodifiable List of the integer numerals contained in the version number.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

parse

public static Runtime.Version parse(String s)

Parses the given string as a valid version string containing a version number followed by pre-release and build information.

Parameters:

s - A string to interpret as a version

Returns:

The Version of the given string

Throws:

IllegalArgumentException - If the given string cannot be interpreted as a valid version

NullPointerException - If the given string is null

NumberFormatException - If an element of the version number or the build number cannot be represented as an Integer

major

public int major()

Returns the major version number.

Returns:

The major version number

minor

public int minor()

Returns the minor version number or zero if it was not set.

Returns:

The minor version number or zero if it was not set

security

public int security()

Returns the security version number or zero if it was not set.

Returns:

The security version number or zero if it was not set

version

public List<Integer> version()

Returns an unmodifiable List of the integer numerals contained in the version number. The List always contains at least one element corresponding to the major version number.

Returns:

An unmodifiable list of the integer numerals contained in the version number

pre

public Optional<String> pre()

Returns the optional pre-release information.

Returns:

The optional pre-release information as a String

build

public Optional<Integer> build()

Returns the build number.

Returns:

The optional build number.

optional

public Optional<String> optional()

Returns optional additional identifying build information.

Returns:

Additional build information as a String

compareTo

public int compareTo(Runtime.Version ob)

Compares this version to another.

Each of the components in the version is compared in the follow order of precedence: version numbers, pre-release identifiers, build numbers, optional build information.

Comparison begins by examining the sequence of version numbers. If one sequence is shorter than another, then the missing elements of the shorter sequence are considered to be less than the corresponding elements of the longer sequence.

A version with a pre-release identifier is always considered to be less than a version without one. Pre-release identifiers are compared numerically when they consist only of digits, and lexicographically otherwise. Numeric identifiers are considered to be less than non-numeric identifiers.

A version without a build number is always less than one with a build number; otherwise build numbers are compared numerically.

The optional build information is compared lexicographically. During this comparison, a version with optional build information is considered to be greater than a version without one.

A version is not comparable to any other type of object.

Specified by:

compareTo in interface Comparable<Runtime.Version>

Parameters:

ob - The object to be compared

Returns:

A negative integer, zero, or a positive integer if this Version is less than, equal to, or greater than the given Version

Throws:

NullPointerException - If the given object is null

compareToIgnoreOptional

public int compareToIgnoreOptional(Runtime.Version ob)

Compares this version to another disregarding optional build information.

Two versions are compared by examining the version string as described in compareTo(Version) with the exception that the optional build information is always ignored.

A version is not comparable to any other type of object.

Parameters:

ob - The object to be compared

Returns:

A negative integer, zero, or a positive integer if this Version is less than, equal to, or greater than the given Version

Throws:

NullPointerException - If the given object is null

toString

public String toString()

Returns a string representation of this version.

Overrides:

toString in class Object

Returns:

The version string

equals

public boolean equals(Object ob)

Determines whether this Version is equal to another object.

Two Versions are equal if and only if they represent the same version string.

This method satisfies the general contract of the Object.equals method.

Overrides:

equals in class Object

Parameters:

ob - The object to which this Version is to be compared

Returns:

true if, and only if, the given object is a Version that is identical to this Version

See Also:

Object.hashCode(), HashMap

equalsIgnoreOptional

public boolean equalsIgnoreOptional(Object ob)

Determines whether this Version is equal to another disregarding optional build information.

Two Versions are equal if and only if they represent the same version string disregarding the optional build information.

Parameters:

ob - The object to which this Version is to be compared

Returns:

true if, and only if, the given object is a Version that is identical to this Version ignoring the optinal build information

hashCode

public int hashCode()

Returns the hash code of this version.

This method satisfies the general contract of the Object.hashCode method.

Overrides:

hashCode in class Object

Returns:

The hashcode of this version

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)