Can Gradle jar multiple projects into one jar?

Question

Can Gradle jar multiple projects into one jar ?

I know you can do it for a single project using a method like this:

task packageTests(type: Jar) {
  from sourceSets.test.classes
}

But how does a person zip up multiple sub-projects into one jar?

I tried this and it doesn't work:

task packageTests(type: Jar) {
  from project(':core').sourceSets.main.classes
  from project(':core:google').sourceSets.test.classes
  from project(':core:bing').sourceSets.test.classes
}

Answer 1

Here's my solution, which is a little bit simpler:

// Create a list of subprojects that you wish to include in the jar.  
def mainProjects = [':apps',':core',':gui',':io']
task oneJar( type: Jar , dependsOn: mainProjects.collect{ it+":compileJava"}) {
    baseName = 'name of jar'
    from files(mainProjects.collect{ project(it).sourceSets.main.output })
}

Code has been tested on Gradle 1.12