Scripting Ant tasks

Despite being primarily a build tool, Apache Ant is a very practical tool for manipulating files including zip files, copy, resource processing, …​ But if ever you’ve been working with a build.xml file or some Jelly script and found yourself a little restricted by all those pointy brackets, or found it a bit weird using XML as a scripting language and wanted something a little cleaner and more straight forward, then maybe Ant scripting with Groovy might be what you’re after.

Groovy has a helper class called AntBuilder which makes the scripting of Ant tasks really easy; allowing a real scripting language to be used for programming constructs (variables, methods, loops, logical branching, classes etc). It still looks like a neat concise version of Ant’s XML without all those pointy brackets; though you can mix and match this markup inside your script. Ant itself is a collection of jar files. By adding them to your classpath, you can easily use them within Groovy as is. We believe using AntBuilder leads to more concise and readily understood syntax.

AntBuilder exposes Ant tasks directly using the convenient builder notation that we are used to in Groovy. Here is the most basic example, which is printing a message on the standard output:

def ant = new groovy.ant.AntBuilder()          (1)
ant.echo('hello from Ant!')         (2)
1 creates an instance of AntBuilder
2 executes the echo task with the message in parameter

Imagine that you need to create a ZIP file. It can be as simple as:

def ant = new AntBuilder() '', basedir: 'src')

In the next example, we demonstrate the use of AntBuilder to copy a list of files using a classical Ant pattern directly in Groovy:

// let's just call one task

// here is an example of a block of Ant inside GroovyMarkup
ant.sequential {
    echo("inside sequential")
    def myDir = "target/AntTest/"
    mkdir(dir: myDir)
    copy(todir: myDir) {
        fileset(dir: "src/test") {
            include(name: "**/*.groovy")

// now let's do some normal Groovy again
def file = new File(ant.project.baseDir,"target/AntTest/some/pkg/MyTest.groovy")
assert file.exists()

Another example would be iterating over a list of files matching a specific pattern:

// let's create a scanner of filesets
def scanner = ant.fileScanner {
    fileset(dir:"src/test") {

// now let's iterate over
def found = false
for (f in scanner) {
    println("Found file $f")
    found = true
    assert f instanceof File
assert found

Or executing a JUnit test:

ant.junit {
    classpath { pathelement(path: '.') }

We can even go further by compiling and executing a Java file directly from Groovy:

ant.echo(file:'', '''
    class Temp {
        public static void main(String[] args) {
ant.javac(srcdir:'.', includes:'', fork:'true')'.', classname:'Temp', fork:'true')

It is worth mentioning that AntBuilder is included in Gradle, so you can use it in Gradle just like you would in Groovy. Additional documentation can be found in the Gradle manual.