Java ver что это

J2SE SDK/JRE Version String Naming Convention

Developers may need to know a product’s version string for various purposes, depending on whether they are developing and deploying a product or downloading and integrating a product.

The following table explains how to interpret SDK/JRE release version string information.

Note that this convention was not in effect prior to the 1.3.0 feature release. The output of java -version has had the same format since 1.3.1.

System Properties and the java -version Command

The output of the java -version command includes a product version identifier and a build identifier. This output is determined by the values of several system properties, and those system properties can themselves be examined programmatically at runtime.

• product version

• Line one displays the product version.

• product version
• product build identifier

• Line one displays the product version.
• Line two displays the build identifier.

Numbering Format Specifications

Every SDK/JRE release that is shipped has a product version string and a build identifier associated with it. The general rules for setting either a version string or a build number string are as follows. For more specific rules and examples, see the following table:

• The content of the java.version system property must always be unique for each external binary.
• A separator is always used between different parts of the string so that ordering can be determined programmically. (For example, a version string of «1.3.1beta» is not acceptable. A version string of «1.3.1-beta» is acceptable.)
• The format should be numeric and in lower case where applicable with a period «.» within the field itself and a dash «-» between fields.
• A period «.» separator indicates a major version.
• An underbar «_» separator is used to indicate an update release.
• A dash «-» separator is used to indicate a non-GA (non-FCS) release.
• A GA (FCS) product version or build identifier must not contain a dash (-).
• No asterik «*» or plus sign «+» is allowed, since these are used as wildcards for the matching logic.
• The content of the java.runtime.version system property can be expanded (beyond that of the java.version system property) to include the build id.
• All GA (FCS) versions are ordered based on the standard dot-notation. For example: 1.3.0 < 1.3.0_01 < 1.3.1 < 1.3.1_01.

Syntax Notation

• Italics indicate syntax that varies.
• identifier> indicates syntax that is present only for any non-GA (non-FCS) release. The identifier is often used to represent a particular milestone, for example:
  • early access
  • beta
  • rc1

  J2SE Release and Version String Information

  • The final digit is always a 0.
  • The — identifier is required for any non-GA (non-FCS) release.
  • A GA (FCS) release never has a — identifier.

  java version "1.3.0" Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-b24) Java HotSpot(TM) Client VM (build 1.3.0-b24, mixed mode) 

  • The final digit is never a 0.
  • The — identifier is required for any non-GA (non-FCS) release.
  • A GA (FCS) release never has a — identifier.

  java version "1.3.1-beta" Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1-beta-b09) Java HotSpot(TM) Client VM (build 1.3.1_05-ea-b01, mixed mode) 

  • The first three digits are identical to those of the feature or maintenance release that is being updated.
  • The two digits following the underbar indicate the update number. The higher the number, the more recent the update.
  • The — identifier is required for any non-GA (non-FCS) release.
  • A GA (FCS) release never has a — identifier.

  java version "1.3.1_05-ea" Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_05-ea-b01) Java HotSpot(TM) Client VM (build 1.3.1_05-ea-b01, mixed mode) 

  The output indicates a GA (FCS) update release having a build identifier of b02.

  java version "1.3.1_05" Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_05-b02) Java HotSpot(TM) Client VM (build 1.3.1_05-b02, mixed mode) 

  The output indicates an early access, update release having a build identifier of b01.

  java version "1.4.0_03-ea" Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_03-ea-b01) Java HotSpot(TM) Client VM (build 1.4.0_03-ea-b01, mixed mode) 

  The output indicates a GA (FCS) update release having a build identifier of b04.

  java version "1.4.0_03" Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_03-b04) Java HotSpot(TM) Client VM (build 1.4.0_03-b04, mixed mode) 

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  Java ver что это

  Oracle’s products evolve as the Java SE platform evolves. Each Oracle product has a version number to indicate which version of the Java SE platform it implements. Version numbers are commonly used for marketing and documentation purposes.

  Oracle has two products that implement the Java SE 8 platform: JDK 8 (Java SE Development Kit 8) and JRE 8 (Java SE Runtime Environment 8).

  Platform and Product Versions

  Platform/Product	Full Name	Abbreviation
  Platform name	Java Platform, Standard Edition 8	Java SE 8
  Product that implements the platform	Java SE Development Kit 8	JDK 8
  Product that implements the platform	Java SE Runtime Environment 8	JRE8

  Version String

  Some of Oracle’s products expose a version string which is separate from, but related to, the version number. This version string is usually only seen by programs which query the runtime environment, or by users who invoke command line tools. Version strings have the form 1.x, or 1.x.0 , where x is the product version number.

  In JDK 8 and JRE 8, the version strings are 1.8 and 1.8.0. Here are some examples where the version string is used:

  • java -version (among other information, returns java version «1.8.0» )
  • java -fullversion (returns java full version «1.8.0-bxx» )
  • javac -source 1.8 (is an alias for javac -source 8 )
  • java.version system property
  • java.vm.version system property
  • @since 1.8 tag values
  • jdk1.8.0 installation directory
  • jre8 installation directory

  Oracle periodically makes updates available and, when an update occurs, the version string will also include the update version number. So, JDK 8 update 5, or JDK 8u5, will have the version string «1.8.0_5». When invoking the java -fullversion command, the result also includes the build number, a level of detail not needed by most users.

  Equivalences

  When the version string for the product is reported as «java version 1.8.0_5», the product will be called JDK 8u5, JDK 8 update 5 or, when the update version is not important, JDK 8.

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