Version (Compiler Tree API 0)

java.lang.Object
- jdk.Version

All Implemented Interfaces:

Comparable<Version>
```
public final class Version
extends Object
implements Comparable<Version>
```
A representation of the JDK version-string which contains a version number optionally followed by pre-release and build information.
Version numbers
A version number, $VNUM, is a non-empty sequence of non-negative integer numerals, without leading or trailing zeroes, separated by period characters (U+002E); i.e., it matches the regular expression ^[1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*$. 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 was 8; the $MAJOR version number of JDK 9 is 9.
- $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. $MINOR is reset to zero when $MAJOR is incremented.
- $SECURITY --- The security level, incremented for a security-update release that contains critical fixes including those necessary to improve security. $SECURITY is reset to zero only when $MAJOR 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 the JDK 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 9.10.0. If one sequence is shorter than another then the missing elements of the shorter sequence are considered to be zero; e.g., 9.1.2 is equal to 9.1.2.0 but 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 an early-access release that's under active development and potentially unstable, or internal, for an internal developer build.
  When comparing two version strings, a string with a pre-release identifier is always less than one with an equal $VNUM but no such identifier. Pre-release identifiers are compared numerically when they consist only of digits, and lexicographically otherwise. Numeric identifiers are less than than non-numeric identifiers.
- $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.
  
  When comparing two version strings with equal $VNUM and $PRE components, a string without a $BUILD component is always less than one with a $BUILD component; otherwise, $BUILD numbers are compared numerically.
- $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.
  
  When comparing two version strings the value of $OPT, if present, may or may not be significant depending on the chosen comparsion method.
A short version string ($SVSTR), often useful in less formal contexts, is simply $VNUM optionally ended with -$PRE.
Since:

9

See Also:

JEP 223: New Version-String Scheme

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Optional<Integer>`	`build()` Returns the build number.
`int`	`compareTo(Version ob)` Compares this version to another.
`int`	`compareToIgnoreOpt(Version ob)` Compares this version to another disregarding optional build information.
`static Version`	`current()` Returns `System.getProperty("java.version")` as a Version.
`boolean`	`equals(Object ob)` Determines whether this `Version` is equal to another object.
`boolean`	`equalsIgnoreOpt(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 Version`	`parse(String s)` Parses the given string as a valid JDK 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 Version parse(String s)
```
    Parses the given string as a valid JDK version string containing a version number followed by pre-release and build information.
    
    Parameters:
    
    s - A string to interpret as a version
    
    Returns:
    
    This version
    
    Throws:
    
    IllegalArgumentException - If the given string cannot be interpreted 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
  - current
```
public static Version current()
```
    Returns System.getProperty("java.version") as a Version.
    
    Returns:
    
    System.getProperty("java.version") as a Version
  - 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(Version ob)
```
    Compares this version to another.
    Two versions are compared 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 zero. If the version numbers are equal, then 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 lexiographically otherwise. Numeric identifiers are considered to be less than non-numeric identifiers. A version without a build value is always less than one with a build value; otherwise build numbers are compared numerically. The optional build information is compared lexiographically. During this comparision, 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<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
  - compareToIgnoreOpt
```
public int compareToIgnoreOpt(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
  - equalsIgnoreOpt
```
public boolean equalsIgnoreOpt(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.
    This method satisfies the general contract of the Object.equals method.
    
    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)

Class Version

Version numbers

Version strings

Method Summary

Methods inherited from class java.lang.Object

Method Detail

parse

current

major

minor

security

version

pre

build

optional

compareTo

compareToIgnoreOpt

toString

equals

equalsIgnoreOpt

hashCode