Java version notation that changes in Java 10

(This article is a multipost with Go to the horizon)

Java has changed to a time-based release since version 10. Along with that, the version notation has changed again, so I have summarized it. [^ 1]

[^ 1]: But almost the same as Java 9

See JEP 322: Time-Based Release Versioning for details.

Version number

There are four notations: $ FEATURE. $ INTERIM. $ UPDATE. $ PATCH. Specifically, it is written as 10.0.1.2. (The notation "Update up to Java 8" has disappeared)

	meaning	timing	Next time	Contents
`$FEATURE`	Feature release	Every six months	March 2018	内容にかかわらずEvery six monthsにリリース Feature additions, incompatible changes, feature removal[^del]including
`$INTERIM`	Intermediate release	no plan	-	Compatible bug fixes and enhancements[^enhancements] (Does not include changes to standard API)
`$UPDATE`	Update release	1 month after feature release, and every 3 months thereafter	April 2018 July 2018	Security fix Bug fixes for the latest features
`$PATCH`	Patch release	Only when needed	-	Minimal fix to solve a serious problem

[^ del]: In this case, it will be announced in at least the previous feature release. [^ enhancements]: It seems that it is supposed to be a case like JDK1.4.1, JDK1.4.2.

Detailed rules

--If all digits after a certain digit are 0, omit it. --Example: 11.0.0.0 → 11 --Example: 11.0.2.0 → 11.0.2 --If $ FEATURE, $ INTERIM is incremented, the numbers after that will be reset. --Example: 11.0.2 → 11.0.2.1 → 11.1 → 11.1.1 --The following is given after the version number --Pre-release identifier (optional) --Example: 11.0.2-ea --Build number --Example: 11.0.2 + 13 --Optional information such as LTS (optional) --Example: 11.0.2 + 13-LTS

Programmatic acquisition

These can be obtained with each method of the Runtime.Version class.

jshell> Runtime.version().feature()
$1 ==> 10

jshell> Runtime.version().interim()
$2 ==> 0

jshell> Runtime.version().update()
$3 ==> 0

jshell> Runtime.version().patch()
$4 ==> 0

jshell> Runtime.version().pre()
$6 ==> Optional.empty

jshell> Runtime.version().build()
$5 ==> Optional[46]

jshell> Runtime.version().toString()
$7 ==> "10+46"

Is it newer than one version? Is it old? If you want to check, it is better to compare with the compareTo method than to compare one by one above.

jshell> Runtime.version().toString()
$1 ==> "10+46"

jshell> Runtime.version().compareTo(Runtime.Version.parse("10.0.1")) > 0
$2 ==> false

jshell> Runtime.version().compareTo(Runtime.Version.parse("9.0.1")) > 0
$3 ==> true

However, Runtime.Version is a class added in Java 9. Please note that if you need to support Java 8 or earlier, you can only get it from the system property java.version.

jshell> System.getProperty("java.version")
$4 ==> "10"

By the way

"Release date [^ 3]" and "Vendor version" have been added to the system properties. For the Oracle JDK, the vendor version seems to remain the originally planned release year.release month.

[^ 3]: To be exact, the GA date. So, the Eary Access version will have a future date.

jshell> System.getProperty("java.version.date")
$1 ==> "2018-03-20"

jshell> System.getProperty("java.vendor.version")
$2 ==> "18.3"