Introduction to Gradle

1. Eng. MSc. Jadson Santos

2. Gradle
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• Gradle is an advanced build tool of general
purpose base on Groovy

3. Why use a build tool?
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4. Why do not use Eclipse to build a system?
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• You can not build automatically from everywhere
with Eclipse
• You will always need a person to build

5. Make
• Makefile is used to compile, linking, assembly
among other tasks such as cleaning up
temporary files, executing commands, etc.
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6. Apache ANT
• The first widely build tool of the Java world
• Ant is extremely flexible and does not impose
coding conventions or directory layouts to the
Java projects
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7. Apache ANT
• Example
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8. Apache ANT
• Example
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9. Apache ANT
• Example
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10. Apache ANT
• Apache Ant cons
• Too flexible
• Write a lot of thing to do a simple build
• The projects have no a standard structure,
everyone create your own structure
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11. Apache Maven
• Simple project setup that follows best practices
- get a new project or module started in
seconds
• Convention over Configuration
• Superior dependency management including
automatic updating, dependency closures (also
known as transitive dependencies)
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12. Apache Maven
• Project
Structure
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13. Apache Maven
• Based on the
concept of a
Project Object
Model (POM)
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14. Apache Maven
• Maven has a central repository
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http://mvnrepository.com/

15. Apache Maven
• Apache Maven Central Repository
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16. Apache Maven
• Apache Maven Central Repository
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17. Apache Maven
• Apache Maven Central Repository
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Central Repository
Exist?
1º
2º
3º
2º / 4º
Local Repository

18. Apache Maven
• Apache Maven cons
• Too hard / rigid
• Use of XML in the build file
• Maven works great for 90% of the most
common things, but complicates a lot for those
10% of specifics things of your project
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19. Apache Maven
• Apache Maven
cons
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20. Why Gradle?
• Gradle combines good parts of both tools and
builds on top of them with DSL and other
improvements
• It has Ant’s power and flexibility
• Maven’s life-cycle and ease of use
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21. Why Gradle?
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22. Why Gradle?
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23. Why Gradle?
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24. Why Gradle?
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• https://gradle.org/maven_vs_gradle/

25. Who is using Gradle?
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26. Who is using Gradle?
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27. Gradle Introduction
• The script of the Gradle is a groovy script with a
DSL to facilitated the tasks necessary to build
• Instead with groovy language of “fors” and “ifs”,
the Gradle DSL helps you
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28. DSL = Domain Specific Language
• Small languages to solve a very specific problem
• Example: SQL
• SQL is an easer way to recovery data, instead use generic
languages:
for(int i = 0 ; i < qtdDiscente; i++){
if(discenteCollection[i].getMatricula() == 2013106430)
discentes.add(new Object[].{discenteCollection[i].getId(),
discenteCollection[i].getMatricula(),
discenteCollection[i].getAnoIngresso()});
}
return discentes;
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29. Gradle DSL
• https://docs.gradle.org/current/dsl/
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30. Gradle Introduction
• Gradle is composed of two concepts: Projects
and Tasks
• A Project may represent the creation of a jar or a
deploy of an application on the server. Each
project is composed of several Tasks
• Tasks represent some atomic job.
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31. Gradle Introduction
• Example of a gradle task
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32. Gradle Introduction
• Like ANT, it allows you to setup default tasks and
dependencies between tasks.
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33. Gradle Introduction
• But will I have to go back to the ANT times and
program every step of my build?
• No! Gradle supports the notion of plugins, like Maven
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34. Gradle Introduction
• Tasks of the Java Plugin
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35. Gradle Introduction
• Like Maven, Gradle uses Convention over
Configuration
• Imagine… What is the Gradle project Structure?
• The same of Maven 
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36. Gradle Introduction
• Dependency management is a critical feature of
every build
• Transitive dependency management
• Support for non-managed dependencies
• Support for custom dependency definitions
• Full Compatibility with Maven and Ivy
• Integration with existing dependency management
infrastructure
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37. Gradle Simple Java Project
• Project Structure
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38. Gradle Simple Java Project
• Project Build File
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Apply Java Plugin
Declare the repository to
download de dependencies
Declare the dependencies
of your application

39. Gradle Simple Web Project
• Project Structure
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40. Gradle Simple Web Project
• Project Build File
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Apply Java and War Plugin
Declare the directory of
web application files

41. Gradle
• Group and Version of your application
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42. Gradle
• Information about source code
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Include source lines and
vars at the .jar generated

43. Gradle
• Declare others repositories
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44. Gradle
• Plugins to configure your application to your
preferred IDE.
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45. Gradle Eclipse Plugin
• Windows -> Eclipse Market -> Gradle ->
Buildship Gradle Integration + Minimalist
Gradle Editor
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46. Gradle Eclipse Plugin
• Importing project as a Gradle Project
• Import as -> Select “Gradle Project”
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47. Gradle Eclipse Plugin
• Importing project as a Gradle Project
• Select the project location
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48. Gradle Eclipse Plugin
• Importing project
as a Gradle
Project
• Use the Gradle
wrapper inside de
project or select
the gradle local
instalation
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49. Gradle Eclipse Plugin
• Buildship Gradle Integration plugin does not come with a
good editor
• Change the default Gradle editor
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50. Gradle Eclipse Plugin
• Executing Gradle in the Eclipse
• Gradle Tasks tab -> Select the tasks -> double click in it
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51. Gradle Eclipse Plugin
• Executing Gradle in the Eclipse
• Usually when you import a Java project as a Gradle Project we
have compilation errors.
• So we need to run the “eclipse” task to Gradle generate the
.classpath e .project files.
• The compilation errors will disappear
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52. Gradle Multiple Projects
• Real applications usually consist in many projects
with dependences between theses projects, for
example a common project that contains common
code used by others projects
• Gradle supports this structure.
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53. Gradle Multiple Projects
• Define a root project that consist of 3 projects
• app
• api
• build.gradle
• impl
• build.gradle
• common
• build.gradle
• build.gradle
• settings.gradle
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54. Gradle Multiple Projects
• File settings.gradle of the root project
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55. Gradle Multiple Projects
• With the buildship plugin, when you import the
root project, all subprojects are imported
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56. Gradle Multiple Projects
• In the build.gradle of the root project you can
apply general configuration for all projects or all
subprojects
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57. Gradle Multiple Projects
• Dependence between projects
• impl project depend of common and api project
• So you can declare theses dependence in build.gradle of impl
project
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58. Gradle Multiple Projects
• Dependence between projects
• impl project depend of common and api project
• So you can declare theses dependence in build.gradle of impl
project
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Eclipse plugin configure the projects
as dependence

59. Gradle Composite builds (3.3)
• “A composite build is simply a build that includes other
builds. In many ways a composite build is similar to a
Gradle multi-project build, except that instead of including
single projects, complete builds are included”.
• https://docs.gradle.org/current/userguide/composite_builds.html
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60. Gradle Composite builds (3.3)
• Your application has several modules, and you change a
module, usually you need build the module, publish the jar
to a repository and update other modules to have the
changes
• Composite builds helps us the split up the project into
smaller, independent builds. You can now quick-fix the
dependency and see the result right away.
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61. Gradle Composite builds (3.3)
• In the settings.gradle file of the root project you can
include others projects build
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62. Gradle Composite builds (3.3)
• Or include all projects under de “modules” directory.
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63. Gradle in the GIT
• .gitignore file for Gradle projects
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64. Converting Maven projects to Gradle
• Execute:
gradle init --type pom
• on the command line that Gradle will generate a
build.gradle from pom.xml file if all used Maven
plug-ins are known by Gradle
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65. Gradle Integration with Jenkins
• Jenkins is an award-winning, cross-platform, continuous
integration and continuous delivery application that
increases your productivity.
• Use Jenkins to build and test your software projects
continuously making it easier for developers to integrate
changes to the project
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66. Gradle Integration with Jenkins
• Jenkins basically schedule jobs (threads) to execute
some task
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http://jenkins.info.ufrn.br/

67. Gradle Integration with Jenkins
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First, we need to install
the Jenkins Gradle
plugin

68. Gradle Integration with Jenkins
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• After install the plugin, in the Jenkins job, select “Invoke
Gradle script” and then write the tasks to be invoked

69. Gradle Integration with Jenkins
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• Projects that generated a JAR to be publish in artefactory

70. Gradle Integration with Jenkins
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• Projects that generated a EAR are deployed in JBOSS
surl.server.deploy.com
user

71. Gradle in practice
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• An exemple of real Gradle script to build a project
structure with a unusual structure that generate a
system.ear file.
• https://jadsonjs.wordpress.com/2016/01/03/build-a-no-usual-project-
with-gradle/

72. Gradle in practice
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Version of the System, at each
build this value needs to be update

73. Gradle in practice
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Information about the source code
Group and Version
of the artifact generated

74. Gradle in practice
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Source Folders of your application

75. Gradle in practice
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Maven Central Repository
Others Repositories

76. Gradle in practice
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Creating 4 own configurations
Some configuration include the
dependences of others
No cache this dependences

77. Gradle in practice
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Our system
dependences
Our own dependences
Dependences
Copied to deploy in JBOSS
Dependences
Can not be Copied to JBOSS

78. Gradle in practice
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To generated an EAR from
complex project structure, it was
created some tasks
Here we define the order how
theses tasks will execute

79. Gradle in practice
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Create the “sigeventos.war”
Copy to the EAR the
dependences and META-INF
directory

80. Gradle in practice
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The power of Gradle: make specific tasks that just exists in your systems

81. Gradle in practice
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Configure the Eclipse class path. Configure Build Path any more!

82. Gradle in practice
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Dependence of the Gradle script

83. Gradle in practice
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Use the org.hidetake.ssh plugin to system deploy:
You can deploy in several serves
Can execute something

84. Gradle in practice
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Information of the JAR in the
repository
Use the org.jfrog.artifactory plugin to publish in our
internal repository:

85. Gradle in practice
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Use the org.flywaydb.flyway plugin to execute SQL
scripts automatically

86. Want to learn more?
• Initial Tutorial:
• http://www.vogella.com/tutorials/Gradle/article.html
• The complete build script:
• https://jadsonjs.wordpress.com/2016/01/03/build-a-no-usual-
project-with-gradle/
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87. Gradle
• Pictures taken from
• https://pt.wikibooks.org/wiki/Programar_em_C/Makefiles
• https://solidsoft.wordpress.com/category/tricks-tips/
• http://pt.slideshare.net/tomek_k/convention-over-configuration-
maven-3-polyglot-maven-gradle-and-ant
• https://kamaondev.wordpress.com/2013/09/16/porque-voce-deve-
trocar-o-maven-pelo-gradle/
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