Gist for "Java Build Tools, JavaScript Package Managers and Task Runners (Part 1)" blog-post.

build.gradle

/* The plugins that our project will use */
apply plugin: 'java'
apply plugin: 'findbugs'
apply plugin: 'pmd'

version = '1.0'

repositories {
    mavenCentral()
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.13'
}

/* Note that certain default configuration will be applied since we did not specify any properties. For example,
   the "classesDir" (The directory to assemble the compiled classes into) has a default location with the "java" plugin:
   "${project.buildDir}/classes/${sourceSet.name}"; where "buildDir" refers to the "/build" directory inside our project. */