JavaTM SE 6, Platform Name and Version

Numbers

At this release, the platform name has changed from J2SETM to JavaTM SE. The official name is

JavaTM Platform, Standard Edition 6.

Both version numbers (1.6.0 and 6) are used to identify this release of the Java Platform.

Version 6 is the product version, while 1.6.0 is the developer version. The number 6 is used to

reflect the evolving level of maturity, stability, scalability and security of Java SE.

Version 6 Used in Platform and Product Names

Version 6 is used in the platform and product names as given in this table:

Full Name Abbreviation

Platform name JavaTM Platform, Standard Edition 6 JavaTM SE 6

Products delivered

under the platform

JavaTM SE Development Kit 6 JDKTM 6

JavaTM SE Runtime Environment 6 JRETM 6

Due to significant popularity within the Java developer community, "JDK" continues to be the

acronym for the development kit, as does "JRE" for the runtime environment. Notice that "JDK"

stands for "Java SE Development Kit" (to distinguish it from the Java EE Development Kit

known as SDK). The name "Java Development Kit" is no longer used, and has not been offically

used since 1.1, prior to the advent of Java EE and Java ME.

Version 1.6.0 Used by Developers

Java SE keeps the version number 1.6.0 (or 1.6) in some places that are visible only to

developers, or where the version number is parsed by programs. As mentioned, 1.6.0 refers to

exactly the same platform and products numbered 6. Version numbers 1.6.0 and 1.6 are used

at:

java -version (among other info, returns java version "1.6.0")

java -fullversion (returns java full version "1.6.0-bxx")

javac -source 1.6 (is an alias for javac -source 6)

java.version system property

java.vm.version system property

@since 1.6 tag values

jdk1.6.0 installation directory

jre1.6.0 installation directory

http://java.sun.com/javase/6 website

Version 1.5.0 or 5.0?

Both version numbers "1.5.0" and "5.0" are used to identify this release of the Java 2 Platform

Standard Edition. Version "5.0" is the product version, while "1.5.0" is the developer version.

The number "5.0" is used to better reflect the level of maturity, stability, scalability and security

of the J2SE.

The number "5.0" was arrived at by dropping the leading "1." from "1.5.0". Where you might

have expected to see 1.5.0, it is now 5.0 (and where it was 1.5, it is now 5).

"Version 5.0" Used in Platform and Product Names

Version 5.0 is used in the platform and product names as given in this table:

Full Name Abbreviation

Platform name JavaTM 2 Platform Standard Edition 5.0 J2SETM 5.0

Products delivered

under the platform

J2SETM Development Kit 5.0 JDKTM 5.0

J2SETM Runtime Environment 5.0 JRE 5.0

Due to significant popularity within the Java developer community, the development kit has

reverted back to the name "JDK" from "Java 2 SDK" (or "J2SDK"), and the runtime

environment has reverted back to "JRE" from "J2RE". Notice that "JDK" stands for "J2SE

Development Kit" (to distinguish it from the J2EE Development Kit). The name "Java

Development Kit" is no longer used, and has not been offically used since 1.1, prior to the advent

of J2EE and J2ME.

As before, the "2" in Java 2 Platform Standard Edition indicates the 2nd generation Java

platform, introduced with J2SE 1.2. This generation number is also used with J2EE and J2ME.

"Version 1.5.0" Used by Developers

J2SE also keeps the version number 1.5.0 (or 1.5) in some places that are visible only to

developers, or where the version number is parsed by programs. As mentioned, 1.5.0 refers to

exactly the same platform and products numbered 5.0. Version numbers 1.5.0 and 1.5 are used

at:

java -version (among other info, returns java version "1.5.0")

java -fullversion (returns java full version "1.5.0-b64")

javac -source 1.5 (javac -source 5 also works)

java.version system property

java.vm.version system property

@since 1.5 tag values

jdk1.5.0 installation directory

jre1.5.0 installation directory

http://java.sun.com/j2se/1.5.0 website (http://java.sun.com/j2se/5.0 also

works)

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

indentifier. This output is determined by the values of several system properties, and those

system properties can themselves be examined programmatically at runtime.

System Property

Name System Property Content

Where Displayed in java -version

Output

java.version product version Line one displays the product

version.

java.runtime.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

Syntax notation used in the following table is:

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:

o early access o beta o rc1

J2SE Release and Version String Information

Release

Type Description Version Numbering Format

Example java -version

Output Strings

Feature Contains new

functionality.

n.n.0<-identifier>

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.

The following output

indicates a GA (FCS) release

having a build indentifier of

b24.

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)

Maintenance Contains

engineering

focused bug

fixes.

n.n.n<-identifier>

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.

The following output

indicates a beta,

maintenance release

having a build identifier of

09.

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)

Update Contains

customer

focused bug

fixes.

n.n.n_nn<-identifier>

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 output indicates an

early access, update

release having a build

identifier of b01.

java version

"1.3.1_05-ea"

Java(TM) 2 Runtime

Environment,

Standard Edition

(build 1.3.1_05-ea-

b01)

Java HotSpot(TM)

The -identifier is required for any non-GA (non-FCS) release.

A GA (FCS) release never has a -identifier.

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)

Also see: