Hi all, my name is Hubert A. Klein Ikkink. Not a very common name, right? To make things easier I just picked the first letters of my firstname and surname and came up with haki. So there you have it, now I am also known as Mr. Haki or mrhaki for short. You can read more blog postings at www.mrhaki.com. I am a passionate Groovy and Java developer based in Tilburg, The Netherlands. My goal is to write clean, elegant, user-centered and high quality software. You can find me on Google+ and Twitter. Hubert is a DZone MVB and is not an employee of DZone and has posted 173 posts at DZone. You can read more from them at their website. View Full User Profile

Gradle Goodness: Init Script for Adding Extra Plugins to Existing Projects

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Gradle is very flexible. One of the ways to alter the build configuration is with initialization or init scripts. These are like other Gradle scripts but are executed before the build. We can use different ways to add the init script to a build. For example we can use the command-line option -I or --init-script, place the script in the init.d directory of our GRADLE_HOME directory or USER_HOME/.gradle directory or place a file init.gradle in our USER_HOME/.gradle directory.

We can also use the apply(from:) method to include such a script in our build file. We can reference a file location, but also a URL. Imagine we place an init script on our company intranet to be shared by all developers, then we can include the script with the apply(from:) method. In the following build file we use this syntax to include the script:

apply plugin: 'java'
apply from: 'http://intranet/source/quality.gradle'

version = '2.1.1'
group = 'com.mrhaki.gradle.sample

he following script is an init script where we add the Checkstyle plugin to projects with the Java plugin and the Codenarc plugin to projects with the Groovy plugin. Because the Groovy plugin extends the Java plugin the Checkstyle plugin is added to the Groovy project as well.

Notice we also add the downloadCheckstyleConfig task. With this task we download from the intranet the Checkstyle configuration that needs to be used by the Checkstyle tasks.

// File: quality.gradle
allprojects {
    afterEvaluate { project ->
        def groovyProject = project.plugins.hasPlugin('groovy')
        def javaProject = project.plugins.hasPlugin('java')

        if (javaProject) {
            // Add Checkstyle plugin.
            project.apply plugin: 'checkstyle'

            // Task to download common Checkstyle configuration
            // from company intranet.
            task downloadCheckstyleConfig(type: DownloadFileTask) {
                description = 'Download company Checkstyle configuration'
                url = 'http://intranet/source/company-style.xml'
                destinationFile = checkstyle.configFile

            // For each Checkstyle task we make sure
            // the company Checkstyle configuration is 
            // first downloaded.
            tasks.withType(Checkstyle) { 
                it.dependsOn 'downloadCheckstyleConfig'

        if (groovyProject) {
            // Add Codenarc plugin.
            project.apply plugin: 'codenarc'

class DownloadFileTask extends DefaultTask {
    String url

    File destinationFile

    def downloadFile() {
        destinationFile.bytes = new URL(url).bytes

Code written with Gradle 1.2




Published at DZone with permission of Hubert Klein Ikkink, author and DZone MVB. (source)

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