Module dependencies for a specific task?

Help/Discuss
1

I have a small Java project using Gradle as build framework (see the current build file here). I’m trying to create a JavaCompile task to compile a single file that represents some kind of optinal “plugin” to the project, and require some additional module dependencies. But I don’t seem to find how to specify a transitive dependency that is only downloaded whenever a specific task is executed (and is ignored for a “standard” build).

Here is what I tried so far:

task compilePlugin(type: JavaCompile) {
    dependencies {
        compile group:'de.dfki.mary', name:'marytts', version:'5.1' 
    }
    source = fileTree(dir: 'src', include: 'opendial/plugins/MaryTTS.java')
    classpath=sourceSets.main.output
    destinationDir = sourceSets.main.output.classesDir
}

The code above does not seem to download the dependencies (let alone add it to the classpath to compile the file). Any ideas how to solve this problem?

2

You’re almost there.
You need to declare a custom configuration, using non-standard name, then you need to declare the dependencies of this configuration, and add this configuration in the classpath of your JavaCompile task, ie

configurations{
myConf
}
dependencies {
myConf group:‘de.dfki.mary’, name:‘marytts’, version:‘5.1’
}

task compilePlugin(type: JavaCompile) {
…
classpath=myConf
…
}

Please note that this will only use the dependencies from myConf
You can also do sth like ‘classpath =myConf +sourceSets.main.compileClasspath’ if needed

1 Like
3

Many thanks, it works perfectly now!
(but I had to set classpath = configurations.myConf instead of classpath=myConf in the task block)

4

Ooops you’re right, forgot the ‘configurations’

5

This should probably be modeled as a separate source set.

6

Yes, @mark_vieira is right.
It’s cleaner to use a source set, as the associated tasks and configurations will be done by Gradle for you

apply plugin: 'java'

sourceSets {
  maryTTS{
    java {
      srcDir 'src'
      include 'opendial/plugins/MaryTTS.java'
    }
  }
}

Now you have already what you need for, i.e. a task named compileMaryTTSJava
and a configuration, called maryTTSCompile

You just have to install your dependency using

dependencies {
  maryTTSCompile 'de.dfki.mary:marytts:5.1'
}

and of course call the compileMaryTTS task

1 Like
7

I’ve done similar things in the past, and it works well.

One things still bugs me, however, which is that sometimes, a custom dependency for a custom configuration is hosted in a custom repository that should not be used for anything else. My solution is to isolate this custom repository/configuration/dependency in its own subproject. But this seems like a hack, and IMHO a more elegant solution would be to be able to declare a repository only for a specific configuration.

Would this feature make sense to anyone else?