Gradle introduction

Basic concepts of Gradle

What is Gradle?

• General purpose build tool

• Tasks and their dependencies on each other. A task has

  • inputs
  • actions
  • outputs

• Fixed build phases

  • Initialization
  • Configuration - only those tasks are configured that are selected to be run
  • Execution - only those tasks are run that are selected

• build scripts are code, but mainly declarative (configuration)

• imperative logic - doLast(), doFirst()

  • Demo by Geri: source
    • task syntax
    • logger (--info, --debug, --stacktrace)
    • dependsOn, finalizedBy, mustRunAfter, (shouldRunAfter)
    • copy task / templating / delete / download
    • depend on other submodules -> :api:public-api:asseamble
    • dry run: --dry-run

• Groovy/Kotlin

• Delegation

Creating a gradle project

gradle init

• Gradle wrapper
  • gradle version used by the project is fixed
  • no need to install it if one starts to work on a project
  • it is possible to create a gradle wrapper bundled with some specific logic in it

Examples...

A mistake...

Multi-project

Delegation in groovy

The basic plugin

• Adds lifecycle tasks
• Adds base extension
  • archivesName
  • ...

Lifecycle tasks

• clean
• check
• assemble
• build

Java plugin

Plugin related tasks

• compile
• jar
• processResources

Source sets

• main
• test
• custom

Configurations for dependencies

Note: script classpath and script dependencies is different from the sourceSets and dependencies above. Dependencies from repositories can be defined in buildscript block.

Java library plugin

• The api dependency

Java application plugin

• run task

Groovy project setup

Groovy environment should be added as dependency.