Apache Lucene DEMO with Gradle

build.gradle

configurations {
    demo
    source
}

repositories {
    mavenCentral()
}

dependencies {
    demo 'org.apache.lucene:lucene-core:3.5.0'
    demo 'org.apache.lucene:lucene-demo:3.5.0'

    source 'org.apache.lucene:lucene-core:3.5.0:sources'
}

task init {
    onlyIf { !file('src').exists() }
    doLast {
        ant.mkdir(dir: 'src')
        ant.unzip(src: configurations.source.singleFile, dest: 'src');
    }
}

task index(type: JavaExec, dependsOn init) {
    main = 'org.apache.lucene.demo.IndexFiles'
    classpath configurations.demo
    args '-docs', 'src'
}

tasks.addRule("Pattern: ?<query>") { String taskName ->
    if (taskName.startsWith("?")) {
        task(taskName, type: JavaExec) {
            main = 'org.apache.lucene.demo.SearchFiles'
            classpath configurations.demo
            args '-query',  taskName[1..-1]
            args '-paging', project.hasProperty('paging') ? paging : 1000
        }
    }
}