CODEWITHSUNDEEP
buildgradle
Hannes
Hannes

Reputation: 5232

Gradle project version property from Java source

In my application I maintain the 'user-frendly' version as a public String constant in the main class.

Is it possible to retrieve this variables in the build.gradle to set the version property of the project? Currently I have to do this manually, what of course can lead to problems.

Upvotes: 0

Views: 1740

Answers (2)

mike rodent
mike rodent

Reputation: 15623

I've plussed Nikita's answer, which is great.

But, firstly, File.toURL() is now deprecated. Something like this would be preferable:

ConfigObject conf = new ConfigSlurper().parse( file("src/main/resources/version.properties").toURI().toURL());

Secondly, note file( ... here, not new File( ... if this line is to be included in build.gradle. The former makes a File relative to the path of the root directory of your Gradle project and is in fact a method of Gradle interface Project. It's worth knowing that every method or property in build.gradle which appears to "come from nowhere" is in fact a method or property of an underlying, "invisible" Gradle Project instance.

If you put new File( "src/main... ") in build.gradle as in Nikita's answer you would in fact not notice any problems if running your Gradle task from a console with current directory the project/root directory... but (according to my experiments) if using the GradleTasks window in Eclipse, for example, you would then be creating a File path relative to the directory where Eclipse was running from... and this would give an error message saying "system cannot find the path specified".

Using file( ..., therefore, you can then go (in build.gradle):

version = conf.versionNumber

NB version here is another property of Project... but you'll be mystified if you look at the above Javadoc for Project, because it's not there! However, you will see getVersion() and setVersion(...). With Groovy every property automatically gets given, by Groovy magic, its own getter and setter method. I took a week out to learn a bit of Groovy, which is actually a fantastic language, and familiarising yourself with it a bit is highly recommended, and makes the learning curve of Gradle substantially less painful.

You can however find the version property in the DSL (domain-specific language) API for Gradle class Project here.

The file version.properties would typically contain something like this:

versionNumber='1.0.0'

NB accessing version from your code ... if you wanted to access this version number from your app code (or test code), you would indeed use new File( ...:

ConfigObject conf = new ConfigSlurper().parse( new File("src/main/resources/version.properties").toURI().toURL());

as in Nikita's answer.

Upvotes: 1

Nikita Skvortsov
Nikita Skvortsov

Reputation: 4923

Correct way of maintaining "user-friendly" version would be version.properties file, stored in your source tree. E.g., under src/main/resources. Then you can load this properties file in Gradle script:

def config = new ConfigSlurper().parse(new File("src/main/resources/version.properties").toURL())
println(config.versionNumber)

Upvotes: 3

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