There are so many small tasks that as solved via a tiny programs. Most of such programs are to call several libraries to have an end-result. In the JVM world, most of those libraries are downloadable from a maven repository.

It could be tricky in general to deliver dependencies for the script to run. There are several possible ways to solve it.

I found an easy way to make Gradle download dependencies and run a script. This makes the scripting done with groovy too.

Here goes an example to run an Amazon API and wrap it as Gradle task:

buildscript {
  repositories {
    jcenter();
  }
  dependencies {
    // List all dependencies for scripting here
    classpath 'com.amazonaws:aws-java-sdk:1.10.48'
  }
}

// Import what is necessay
import com.amazonaws.auth.profile.ProfileCredentialsProvider
import com.amazonaws.services.s3.AmazonS3Client

task runScriptForAmazon << {
  // The script source goes here!
  def s3client = new AmazonS3Client(new ProfileCredentialsProvider())
  println "Working with endpoint: $s3client.endpoint"
}

The only trick here is that Gradle includes all script dependencies into classpath where tasks are loaded and executed.

Even more, adding Gradle Wrapper makes it runnable on eveny machine with JVM only. (A Wrapper task can be used to have Gradle generate wrapper scripts)

Happy scripting!