Java SemVer v0.7.2 (SemVer 2)

Java SemVer is a Java implementation of the Semantic Versioning Specification (http://semver.org/).

Versioning

Java SemVer is versioned according to the SemVer Specification.

NOTE: The current release of the Java SemVer library has a major version of zero which according to the SemVer p.4 means that the library is under initial development and its public API should not be considered stable.

Table of Contents

• Installation
• Usage
  • Creating Versions
  • Incrementing Versions
  • Comparing Versions
• SemVer Expressions API (Ranges)
• Bugs and Features
• License

Installation

To install the Java SemVer libary add the following dependency to your Maven project.

Current stable version

<dependency>
  <groupId>com.github.zafarkhaja</groupId>
  <artifactId>java-semver</artifactId>
  <version>0.7.2</version>
</dependency>

Development version

<dependency>
  <groupId>com.github.zafarkhaja</groupId>
  <artifactId>java-semver</artifactId>
  <version>0.8.0-SNAPSHOT</version>
</dependency>

NOTE: To use the development version you need to add the SNAPSHOT repository to your pom.xml file: http://oss.sonatype.org/content/repositories/snapshots/.

Usage

Below are some common use cases for the Java SemVer library.

Creating Versions

The main class of the Java SemVer library is Version which implements the Facade design pattern. By design, the Version class is made immutable by making its constructors package-private, so that it can not be subclassed or directly instantiated. Instead of public constructors, the Version class provides few static factory methods.

One of the methods is the Version.valueOf method.

import com.github.zafarkhaja.semver.Version;

Version v = Version.valueOf("1.0.0-rc.1+build.1");

int major = v.getMajorVersion(); // 1
int minor = v.getMinorVersion(); // 0
int patch = v.getPatchVersion(); // 0

String normal     = v.getNormalVersion();     // "1.0.0"
String preRelease = v.getPreReleaseVersion(); // "rc.1"
String build      = v.getBuildMetadata();     // "build.1"

String str = v.toString(); // "1.0.0-rc.1+build.1"

The other static factory method is Version.forIntegers which is also overloaded to allow fewer arguments.

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.forIntegers(1);
Version v2 = Version.forIntegers(1, 2);
Version v3 = Version.forIntegers(1, 2, 3);

Another way to create a Version is to use a builder class Version.Builder.

import com.github.zafarkhaja.semver.Version;

Version.Builder builder = new Version.Builder("1.0.0");
builder.setPreReleaseVersion("rc.1");
builder.setBuildMetadata("build.1");

Version v = builder.build();

int major = v.getMajorVersion(); // 1
int minor = v.getMinorVersion(); // 0
int patch = v.getPatchVersion(); // 0

String normal     = v.getNormalVersion();     // "1.0.0"
String preRelease = v.getPreReleaseVersion(); // "rc.1"
String build      = v.getBuildMetadata();     // "build.1"

String str = v.toString(); // "1.0.0-rc.1+build.1"

Incrementing Versions

Because the Version class is immutable, the incrementors return a new instance of Version rather than modifying the given one. Each of the normal version incrementors has an overloaded method that takes a pre-release version as an argument.

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.valueOf("1.2.3");

// Incrementing the major version
Version v2 = v1.incrementMajorVersion();        // "2.0.0"
Version v2 = v1.incrementMajorVersion("alpha"); // "2.0.0-alpha"

// Incrementing the minor version
Version v3 = v1.incrementMinorVersion();        // "1.3.0"
Version v3 = v1.incrementMinorVersion("alpha"); // "1.3.0-alpha"

// Incrementing the patch version
Version v4 = v1.incrementPatchVersion();        // "1.2.4"
Version v4 = v1.incrementPatchVersion("alpha"); // "1.2.4-alpha"

// Original Version is still the same
String str = v1.toString(); // "1.2.3"

There are also incrementor methods for the pre-release version and the build metadata.

import com.github.zafarkhaja.semver.Version;

// Incrementing the pre-release version
Version v1 = Version.valueOf("1.2.3-rc");        // considered as "rc.0"
Version v2 = v1.incrementPreReleaseVersion();    // "1.2.3-rc.1"
Version v3 = v2.incrementPreReleaseVersion();    // "1.2.3-rc.2"

// Incrementing the build metadata
Version v1 = Version.valueOf("1.2.3-rc+build");  // considered as "build.0"
Version v2 = v1.incrementBuildMetadata();        // "1.2.3-rc+build.1"
Version v3 = v2.incrementBuildMetadata();        // "1.2.3-rc+build.2"

When incrementing the normal or pre-release versions the build metadata is always dropped.

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.valueOf("1.2.3-beta+build");

// Incrementing the normal version
Version v2 = v1.incrementMajorVersion();        // "2.0.0"
Version v2 = v1.incrementMajorVersion("alpha"); // "2.0.0-alpha"

Version v3 = v1.incrementMinorVersion();        // "1.3.0"
Version v3 = v1.incrementMinorVersion("alpha"); // "1.3.0-alpha"

Version v4 = v1.incrementPatchVersion();        // "1.2.4"
Version v4 = v1.incrementPatchVersion("alpha"); // "1.2.4-alpha"

// Incrementing the pre-release version
Version v2 = v1.incrementPreReleaseVersion();   // "1.2.3-beta.1"

NOTE: The discussion page https://github.com/mojombo/semver/issues/60 might be of good use in better understanding some of the decisions made regarding the incrementor methods.

Comparing Versions

Comparing versions with Java SemVer is easy. The Version class implements the Comparable interface, it also overrides the Object.equals method and provides some more methods for convenient comparing.

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.valueOf("1.0.0-rc.1+build.1");
Version v2 = Version.valueOf("1.3.7+build.2.b8f12d7");

int result = v1.compareTo(v2);  // < 0
boolean result = v1.equals(v2); // false

boolean result = v1.greaterThan(v2);           // false
boolean result = v1.greaterThanOrEqualTo(v2);  // false
boolean result = v1.lessThan(v2);              // true
boolean result = v1.lessThanOrEqualTo(v2);     // true

When determining version precedence the build metadata is ignored (SemVer p.10).

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.valueOf("1.0.0+build.1");
Version v2 = Version.valueOf("1.0.0+build.2");

int result = v1.compareTo(v2);  // = 0
boolean result = v1.equals(v2); // true

Sometimes, however, you might want to compare versions with the build metadata in mind. For such cases Java SemVer provides a comparator Version.BUILD_AWARE_ORDER and a convenience method Version.compareWithBuildsTo.

import com.github.zafarkhaja.semver.Version;

Version v1 = Version.valueOf("1.0.0+build.1");
Version v2 = Version.valueOf("1.0.0+build.2");

int result = Version.BUILD_AWARE_ORDER.compare(v1, v2);  // < 0

int result     = v1.compareTo(v2);            // = 0
boolean result = v1.equals(v2);               // true
int result     = v1.compareWithBuildsTo(v2);  // < 0

SemVer Expressions API (Ranges)

Since version 0.7.0 Java SemVer supports the SemVer Expressions API which is implemented as an external DSL. The BNF grammar for the SemVer Expressions DSL can be found in the corresponding issue "Implement the SemVer Expressions API".

The entry point for the API is the Version.satisfies method.

import com.github.zafarkhaja.semver.Version;

Version v = Version.valueOf("1.0.0-beta");
boolean result = v.satisfies(">=1.0.0 & <2.0.0");  // false

Below are examples of some common use cases, as well as syntactic sugar and some other interesting capabilities of the SemVer Expressions DSL.

• Wildcard - 1.* which is equivalent to >=1.0.0 & <2.0.0
• Tilde operator - ~1.5 which is equivalent to >=1.5.0 & <2.0.0
• Range - 1.0-2.0 which is equivalent to >=1.0.0 & <=2.0.0
• Negation operator - !(1.*) which is equivalent to <1.0.0 & >=2.0.0
• Short notation - 1 which is equivalent to =1.0.0
• Parenthesized expression - ~1.3 | (1.4.* & !=1.4.5) | ~2

Bugs and Features

Bug reports and feature requests can be submitted at https://github.com/zafarkhaja/java-semver/issues.

License

Java SemVer is licensed under the MIT License - see the LICENSE file for details.