Gradle is a popular build management system. The Gradle framework has features for the automatic download and configuration of the libraries which are required for the build. The library dependencies can be downloaded from Maven and Ivy repositories. Gradle can handle multiple projects and multiple artifact-based builds.<\/p>\n
Table Of Contents<\/h3>\n\n- 1. Overview<\/a><\/dt>\n
- 2. Gradle Build System Tutorial<\/a><\/dt>\n
- \n
\n- 2.1. Prerequisites<\/a><\/dt>\n
- 2.2. Download<\/a><\/dt>\n
- 2.3. Setup<\/a><\/dt>\n
- 2.4. Running Gradle<\/a><\/dt>\n
- 2.5. Gradle Projects<\/a><\/dt>\n
- 2.6. Gradle Tasks<\/a><\/dt>\n
- 2.7. Gradle Plugins<\/a><\/dt>\n
- 2.8. Gradle Java Project<\/a><\/dt>\n
- 2.9. Gradle Wrapper<\/a><\/dt>\n
- 2.10. Gradle Custom Tasks<\/a><\/dt>\n
- 2.11. Gradle Testing<\/a><\/dt>\n
- 2.12. Gradle Deployment<\/a><\/dt>\n
- 2.13. Gradle Custom Plugins<\/a><\/dt>\n
- 2.14. Gradle Eclipse Integration<\/a><\/dt>\n
- 2.15. Gradle build scans<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 3. Download the Source Code<\/a><\/dt>\n<\/dl>\n<\/div>\n
<\/p>\n
<\/a>2. Gradle Build System Tutorial<\/h2>\n<\/a>2.1 Prerequisites<\/h3>\nJava 8 is required on the Linux, windows, or Mac operating systems. Gradle 5.4.1 version can be used for building Gradle projects. <\/p>\n
<\/a>2.2 Download<\/h3>\nYou can download Java 8 from the Oracle web site<\/a>. Likewise, Gradle 5.4.1 can be downloaded from this website<\/a>. <\/p>\n<\/a>2.3 Setup<\/h3>\n2.3.1 Java Setup<\/h4>\n
You can set the environment variables for JAVA_HOME and PATH. They can be set as shown below.<\/em><\/p>\nJava Environment Setup<\/em><\/span><\/p>\nJAVA_HOME=\"\/desktop\/jdk1.8.0_73\"\nexport JAVA_HOME\nPATH=$JAVA_HOME\/bin:$PATH\nexport PATH\n<\/pre>\n2.3.2 Gradle Setup<\/h4>\n
The environment variables for Gradle are set as below:<\/p>\n
Gradle Setup<\/em><\/span><\/p>\nGRADLE_HOME=\"\/opt\/gradle\/gradle-5.4.1\/bin\"\nexport GRADLE_HOME=$GRADLE_HOME\/bin\/\nexport PATH=$PATH:$GRADLE_HOME\n<\/pre>\n<\/a>2.4 Running Gradle<\/h3>\nYou can check the version of the Gradle by using the command Gradle \u2013-version. The command for running Gradle is as below:<\/p>\n
Command<\/em><\/span><\/p>\ngradle --version\n<\/pre>\nThe output of the executed Gradle command is shown below.<\/p>\n
Gradle Version<\/em><\/span><\/p>\napples-MacBook-Air:~ bhagvan.kommadi$ gradle --version\n\nWelcome to Gradle 5.5.1!\n\nHere are the highlights of this release:\n - Kickstart Gradle plugin development with gradle init\n - Distribute organization-wide Gradle properties in custom Gradle distributions\n - Transform dependency artifacts on resolution\n\nFor more details see https:\/\/docs.gradle.org\/5.5.1\/release-notes.html\n\n\n------------------------------------------------------------\nGradle 5.5.1\n------------------------------------------------------------\n\nBuild time: 2019-07-10 20:38:12 UTC\nRevision: 3245f748c7061472da4dc184991919810f7935a5\n\nKotlin: 1.3.31\nGroovy: 2.5.4\nAnt: Apache Ant(TM) version 1.9.14 compiled on March 12 2019\nJVM: 1.8.0_101 (Oracle Corporation 25.101-b13)\nOS: Mac OS X 10.12.6 x86_64\n<\/pre>\n2.4.1 Gradle Hello World<\/h4>\n
Let us look at Gradle Hello World. You can create a task as shown below in build.gradle<\/code>:<\/p>\nSetup<\/em><\/span><\/p>\ntask helloworld {\n doLast {\n println 'Hello World'\n }\n}\n<\/pre>\nThe command to execute above task is shown below:<\/p>\n
Command<\/em><\/span><\/p>\ngradle helloworld\n<\/pre>\nThe output of the command executed is as below:<\/p>\n
Command<\/em><\/span><\/p>\napples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle helloworld\nStarting a Gradle Daemon (subsequent builds will be faster)\n\n> Task :helloworld\nHello World\n\nBUILD SUCCESSFUL in 8s\n1 actionable task: 1 executed\n<\/pre>\n<\/a>2.5 Gradle Projects<\/h3>\nEvery Gradle project has tasks. A Gradle task is a unit of work to execute a build. The compilation of source code and generation of Javadoc are examples of Gradle tasks. The project name is mentioned in settings.gradle<\/code> as shown below.<\/p>\nsettings.gradle<\/em><\/span><\/p>\nrootProject.name ='org.javacodegeeks.gradle.saygreetings'\n<\/pre>\nbuild.gradle<\/code> is written as below:<\/p>\nbuild.gradle<\/em><\/span><\/p>\ndescription =\"\"\"\nExample project for a Gradle build\nProject name: ${project.name}\n\nMore detailed information here... \"\"\"\n\ntask saygreetings {\n doLast {\n println 'Greetings'\n }\n}\n<\/pre>\nThe command to execute above task is shown below:<\/p>\n
Command<\/em><\/span><\/p>\ngradle saygreetings\n<\/pre>\nThe output of the command executed is as below:<\/p>\n
Output<\/em><\/span><\/p>\napples-MacBook-Air:project bhagvan.kommadi$ gradle saygreetings\n\n> Task :saygreetings\nGreetings\n\nBUILD SUCCESSFUL in 1s\n1 actionable task: 1 executed\n<\/pre>\nAn enterprise application will have multiple projects to be built. The Gradle framework has a root project which can have multiple sub-projects. build. Gradle file has the root project. The file settings.gradle will have the subprojects information.<\/p>\n
For example, you can have the project structure as below:<\/p>\n
\n- base_project\n
\n- auth<\/li>\n
- usermgmt<\/li>\n
- utils<\/li>\n<\/ul>\n<\/li>\n
- settings.gradle<\/li>\n<\/ul>\n
Based on the project structure, you can have the settings.gradle.<\/p>\n
build.gradle<\/em><\/span><\/p>\ninclude 'auth', 'usermgmt', 'utils'\n\n#include 'auth'\n#include 'usermgmt'\n#include 'utils'\n<\/pre>\n<\/a>2.6 Gradle Tasks<\/h3>\nThe Gradle task is used to create tasks such as jar creation and archive publishing. The Gradle framework is extensible. Tasks are the core part of the framework. A Gradle task can be created for moving data from a directory to the other directory. A task can have a dependency on another task. It can have an input and the output. Gradle has introspection related tasks.
<\/div> <\/div><\/p>\nFor example, the tasks command shows the available tasks for a project. This command shows the base tasks when you do not have a build.gradle<\/code> file.<\/p>\nTasks command<\/em><\/span><\/p>\ngradle -q tasks\n<\/pre>\nThe output of the command executed is as below:<\/p>\n
Tasks command output<\/em><\/span><\/p>\napples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle -q tasks\n\n------------------------------------------------------------\nTasks runnable from root project\n------------------------------------------------------------\n\nBuild Setup tasks\n-----------------\ninit - Initializes a new Gradle build.\nwrapper - Generates Gradle wrapper files.\n\nHelp tasks\n----------\nbuildEnvironment - Displays all buildscript dependencies declared in root project 'gradlesystem'.\ncomponents - Displays the components produced by root project 'gradlesystem'. [incubating]\ndependencies - Displays all dependencies declared in root project 'gradlesystem'.\ndependencyInsight - Displays the insight into a specific dependency in root project 'gradlesystem'.\ndependentComponents - Displays the dependent components of components in root project 'gradlesystem'. [incubating]\nhelp - Displays a help message.\nmodel - Displays the configuration model of root project 'gradlesystem'. [incubating]\nprojects - Displays the sub-projects of root project 'gradlesystem'.\nproperties - Displays the properties of root project 'gradlesystem'.\ntasks - Displays the tasks runnable from root project 'gradlesystem'.\n\nTo see all tasks and more detail, run gradle tasks --all\n\nTo see more detail about a task, run gradle help --task \n<\/pre>\nGradle has helped the task to give information related to the other tasks such as the init task. The command executed for help task related to init is shown below:<\/p>\n
Help for Init task<\/em><\/span><\/p>\ngradle -q help --task init\n<\/pre>\nThe output of the command executed is as below:<\/p>\n
Help for Init task output<\/em><\/span><\/p>\napples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle -q help --task init\nDetailed task information for init\n\nPath\n :init\n\nType\n InitBuild (org.gradle.buildinit.tasks.InitBuild)\n\nOptions\n --dsl Set the build script DSL to be used in generated scripts.\n Available values are:\n groovy\n kotlin\n\n --package Set the package for source files.\n\n --project-name Set the project name.\n\n --test-framework Set the test framework to be used.\n Available values are:\n junit\n junit-jupiter\n kotlintest\n scalatest\n spock\n testng\n\n --type Set the type of project to generate.\n Available values are:\n basic\n cpp-application\n cpp-library\n groovy-application\n groovy-gradle-plugin\n groovy-library\n java-application\n java-gradle-plugin\n java-library\n kotlin-application\n kotlin-gradle-plugin\n kotlin-library\n pom\n scala-library\n\nDescription\n Initializes a new Gradle build.\n\nGroup\n Build Setup\n<\/pre>\n<\/a>2.7 Gradle Plugins<\/h3>\nGradle has an extension for a plugin for preconfigured tasks. It has a base set of plugins and developers can add custom plugins. build.gradle file has plugin specified using the statement apply plugin ‘plugin-name’.<\/p>\n
You can add the entry apply plugin: 'com.android.application'<\/code> which sets the Android plug-in available for a Gradle build. Gradle has a registry of plugins which can be accessed at site<\/a>.<\/p>\n<\/a>2.8 Gradle Java Project<\/h3>\nThe Gradle framework has features for java projects. You can create a new Gradle based Java project for JUnit Jupiter.<\/p>\n
build.gradle<\/em><\/span><\/p>\ngradle init --type java-library --test-framework junit-jupiter\n<\/pre>\nThe output of the command executed is as below:<\/p>\n
build.gradle<\/em><\/span><\/p>\napples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle init --type java-library --test-framework junit-jupiter\n\nSelect build script DSL:\n 1: Groovy\n 2: Kotlin\nEnter selection (default: Groovy) [1..2] 1\n\nProject name (default: gradlesystem): junit\nSource package (default: junit): junit\n\n> Task :init\nGet more help with your project: https:\/\/docs.gradle.org\/5.5.1\/userguide\/java_library_plugin.html\n\nBUILD SUCCESSFUL in 50s\n2 actionable tasks: 2 executed\n<\/pre>\nJava code generated related to the command above is presented below:<\/p>\n
Library class<\/em><\/span><\/p>\n\/*\n * This Java source file was generated by the Gradle 'init' task.\n *\/\npackage junit;\n\npublic class Library {\n public boolean someLibraryMethod() {\n return true;\n }\n}\n<\/pre>\nThe code generated for Junit Test is shown below:<\/p>\n
Junit class<\/em><\/span><\/p>\n\/*\n * This Java source file was generated by the Gradle 'init' task.\n *\/\npackage junit;\n\nimport org.junit.jupiter.api.Test;\nimport static org.junit.jupiter.api.Assertions.*;\n\nclass LibraryTest {\n @Test void testSomeLibraryMethod() {\n Library classUnderTest = new Library();\n assertTrue(classUnderTest.someLibraryMethod(), \"someLibraryMethod should return 'true'\");\n }\n}\n<\/pre>\nYou can execute the build using the command below:<\/p>\n
build command<\/em><\/span><\/p>\ngradle build\n<\/pre>\nThe output of the command executed is presented below:<\/p>\n
build command output<\/em><\/span><\/p>\napples-MacBook-Air:junit bhagvan.kommadi$ gradle build\nBUILD SUCCESSFUL in 31s\n4 actionable tasks: 4 up-to-date\n<\/pre>\nThe command for executing the junit test is shown below:<\/p>\n
build command<\/em><\/span><\/p>\ngradle test\n<\/pre>\nThe output of the command executed is presented below:<\/p>\n
build command output<\/em><\/span><\/p>\napples-MacBook-Air:junit bhagvan.kommadi$ gradle test\nBUILD SUCCESSFUL in 35s\n3 actionable tasks: 3 up-to-date\n<\/pre>\n<\/a>2.9 Gradle Wrapper<\/h3>\nThe Gradle wrapper is used for executing the build with a predefined Gradle version and settings. Gradle version download happens when the Gradle wrapper is executed. The Gradle wrapper can be created using command Gradle wrapper<\/p>\n
gradlew<\/code> is created for mac and Unix systems. gradlew.batis created for window systems. These files are executed when the Gradle command is executed. Gradle wrapper version can be specified in a Gradle task. When the task is executed, Gradle wrapper is created and it downloads the Gradle based on the version. Gradle wrapper version can be specified as shown below:<\/p>\nGradle wrapper<\/em><\/span><\/p>\nwrapper {\n gradleVersion = '4.9'\n}\n<\/pre>\nGradle options can be specified in the gradlew<\/code> or gradlew.bat<\/code> file.<\/p>\ngradle wrapper options<\/em><\/span><\/p>\n#!\/usr\/bin\/env bash\nDEFAULT_JVM_OPTS=\"-Xmx1024m\"\n<\/pre>\n<\/a>2.10 Gradle Custom Tasks<\/h3>\nA gradle custom task can be created and it can be derived from other tasks. For example, CopyTask can be created to copy files.<\/p>\n
A copyTask can be created in a build.gradle<\/code> file as shown below:<\/p>\ncustom task<\/em><\/span><\/p>\ntask copyTask(type: Copy) {\n from 'src'\n into 'dest'\n}\n<\/pre>\nYou can create an src folder inside this project and add an example.txt text file to this folder. copy task will copy the example.txt<\/code> file to a new dest folder.<\/p>\nThe command to execute above task is shown below:<\/p>\n
custom task run command<\/em><\/span><\/p>\ngradle copyTask\n<\/pre>\nThe output of the command executed is presented below:<\/p>\n
custom task output<\/em><\/span><\/p>\napples-MacBook-Air:customtask bhagvan.kommadi$ gradle copyTask\n\nBUILD SUCCESSFUL in 4s\n1 actionable task: 1 up-to-date\n<\/pre>\n<\/a>2.11 Gradle Testing<\/h3>\nGradle 6.0 has features for unit testing with Junit 5. you can add dependencies in the build.gradle<\/code> file as shown below.<\/p>\ncustom task<\/em><\/span><\/p>\ndependencies {\n\n \n testImplementation(enforcedPlatform(\"org.junit:junit-bom:5.4.0\")) \n testImplementation(\"org.junit.jupiter:junit-jupiter\")\n}\n<\/pre>\nGradle test task helps in finding the compiled classes in the project source folder. <\/p>\n
<\/a>2.12 Gradle Deployment<\/h3>\nGradle provides support for deploying build artifacts to artifact repositories, such as Artifactory or Sonatype Nexus. You can use a maven-publish plugin for publishing build artifacts.<\/p>\n
<\/a>2.13 Gradle Custom Plugins<\/h3>\nA gradle custom plugin can be created to have a plugin with custom logic. The build file will have simple and straightforward tasks. The build needs to have declarative logic to have better maintenance.<\/p>\n
<\/a>2.14 Gradle – Eclipse Integration<\/h3>\nYou can find the source code for installing Gradle Plugin using the Grails project in this javacodegeeks article<\/a>.<\/p>\nYou need to also ensure that the Buildship Gradle Integration plugin is installed. The snapshot below shows the installed Gradle version.<\/p>\n
\n![\"gradle](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/eclipse_gradle.jpg\")
Eclipse \u2013 Gradle plugin<\/figcaption><\/figure>\n<\/div>\n2.14.1 Building with Gradle – Eclipse<\/h4>\n
You can import the project HelloWorld which was a Gradle project created. The snapshot below shows the import wizard from the Eclipse menu File-> Import.<\/p>\n
\n![\"gradle](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/eclipse_import_gradle.jpg\")
Eclipse \u2013 Import Gradle Project<\/figcaption><\/figure>\n<\/div>\nAfter the import, the Gradle Grails project can be viewed in the eclipse. The screen shot below shows the imported project.<\/p>\n
\n![\"gradle](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/gradle_grails_eclipse.jpg\")
Gradle Grails Eclipse Project<\/figcaption><\/figure>\n<\/div>\nFrom the Gradle tasks view, You can see all the Gradle tasks. To execute the grails-app, click on bootRun. The screenshot below shows the Gradle tasks view.<\/p>\n
\n![\"\"](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/gradle_tasks_view.jpg\")
Gradle Tasks Eclipse View<\/figcaption><\/figure>\n<\/div>\nThe grails app can be accessed at http:\/\/localhost:8080 when the gradle runs the Grails app on eclipse. The snapshot of the Grails app and Gradle task execution is shown below.<\/p>\n
\n![\"\"](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/browser_grails_app_eclipse.jpg\")
Grails App Running \u2013 Eclipse<\/figcaption><\/figure>\n<\/div>\nThe HelloController<\/code> can be accessed and the page renders to show the \u201cGreetings\u201d message. The rendered page is shown below:<\/p>\n\n![\"\"](\"https:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2019\/06\/hello_index_eclipse_grails.jpg\")
Hello Controller \u2013 Eclipse<\/figcaption><\/figure>\n<\/div>\nGradle provides several plugins for analyzing the code base of a Gradle project.<\/p>\n
<\/a>2.15 Gradle Build Scans<\/h3>\nThe Gradle project can have a build scanner. A build scan has incidents and details of a Gradle build project. The Gradle remote server will have the build scans which are published. Gradle init is used for creating a project. The command is shown below:<\/p>\n
gradle project create command<\/em><\/span><\/p>\ngradle init \n<\/pre>\nYou can use build scan option to publish the build scan as shown below:<\/p>\n
- \n
- 2.1. Prerequisites<\/a><\/dt>\n
- 2.2. Download<\/a><\/dt>\n
- 2.3. Setup<\/a><\/dt>\n
- 2.4. Running Gradle<\/a><\/dt>\n
- 2.5. Gradle Projects<\/a><\/dt>\n
- 2.6. Gradle Tasks<\/a><\/dt>\n
- 2.7. Gradle Plugins<\/a><\/dt>\n
- 2.8. Gradle Java Project<\/a><\/dt>\n
- 2.9. Gradle Wrapper<\/a><\/dt>\n
- 2.10. Gradle Custom Tasks<\/a><\/dt>\n
- 2.11. Gradle Testing<\/a><\/dt>\n
- 2.12. Gradle Deployment<\/a><\/dt>\n
- 2.13. Gradle Custom Plugins<\/a><\/dt>\n
- 2.14. Gradle Eclipse Integration<\/a><\/dt>\n
- 2.15. Gradle build scans<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 3. Download the Source Code<\/a><\/dt>\n<\/dl>\n<\/div>\n
<\/p>\n
<\/a>2. Gradle Build System Tutorial<\/h2>\n
<\/a>2.1 Prerequisites<\/h3>\n
Java 8 is required on the Linux, windows, or Mac operating systems. Gradle 5.4.1 version can be used for building Gradle projects. <\/p>\n
<\/a>2.2 Download<\/h3>\n
You can download Java 8 from the Oracle web site<\/a>. Likewise, Gradle 5.4.1 can be downloaded from this website<\/a>. <\/p>\n
<\/a>2.3 Setup<\/h3>\n
2.3.1 Java Setup<\/h4>\n
You can set the environment variables for JAVA_HOME and PATH. They can be set as shown below.<\/em><\/p>\n
Java Environment Setup<\/em><\/span><\/p>\n
JAVA_HOME=\"\/desktop\/jdk1.8.0_73\"\nexport JAVA_HOME\nPATH=$JAVA_HOME\/bin:$PATH\nexport PATH\n<\/pre>\n
2.3.2 Gradle Setup<\/h4>\n
The environment variables for Gradle are set as below:<\/p>\n
Gradle Setup<\/em><\/span><\/p>\n
GRADLE_HOME=\"\/opt\/gradle\/gradle-5.4.1\/bin\"\nexport GRADLE_HOME=$GRADLE_HOME\/bin\/\nexport PATH=$PATH:$GRADLE_HOME\n<\/pre>\n
<\/a>2.4 Running Gradle<\/h3>\n
You can check the version of the Gradle by using the command Gradle \u2013-version. The command for running Gradle is as below:<\/p>\n
Command<\/em><\/span><\/p>\n
gradle --version\n<\/pre>\n
The output of the executed Gradle command is shown below.<\/p>\n
Gradle Version<\/em><\/span><\/p>\n
apples-MacBook-Air:~ bhagvan.kommadi$ gradle --version\n\nWelcome to Gradle 5.5.1!\n\nHere are the highlights of this release:\n - Kickstart Gradle plugin development with gradle init\n - Distribute organization-wide Gradle properties in custom Gradle distributions\n - Transform dependency artifacts on resolution\n\nFor more details see https:\/\/docs.gradle.org\/5.5.1\/release-notes.html\n\n\n------------------------------------------------------------\nGradle 5.5.1\n------------------------------------------------------------\n\nBuild time: 2019-07-10 20:38:12 UTC\nRevision: 3245f748c7061472da4dc184991919810f7935a5\n\nKotlin: 1.3.31\nGroovy: 2.5.4\nAnt: Apache Ant(TM) version 1.9.14 compiled on March 12 2019\nJVM: 1.8.0_101 (Oracle Corporation 25.101-b13)\nOS: Mac OS X 10.12.6 x86_64\n<\/pre>\n
2.4.1 Gradle Hello World<\/h4>\n
Let us look at Gradle Hello World. You can create a task as shown below in
build.gradle<\/code>:<\/p>\nSetup<\/em><\/span><\/p>\n
task helloworld {\n doLast {\n println 'Hello World'\n }\n}\n<\/pre>\nThe command to execute above task is shown below:<\/p>\n
Command<\/em><\/span><\/p>\n
gradle helloworld\n<\/pre>\n
The output of the command executed is as below:<\/p>\n
Command<\/em><\/span><\/p>\n
apples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle helloworld\nStarting a Gradle Daemon (subsequent builds will be faster)\n\n> Task :helloworld\nHello World\n\nBUILD SUCCESSFUL in 8s\n1 actionable task: 1 executed\n<\/pre>\n
<\/a>2.5 Gradle Projects<\/h3>\n
Every Gradle project has tasks. A Gradle task is a unit of work to execute a build. The compilation of source code and generation of Javadoc are examples of Gradle tasks. The project name is mentioned in
settings.gradle<\/code> as shown below.<\/p>\nsettings.gradle<\/em><\/span><\/p>\n
rootProject.name ='org.javacodegeeks.gradle.saygreetings'\n<\/pre>\n
build.gradle<\/code> is written as below:<\/p>\nbuild.gradle<\/em><\/span><\/p>\n
description =\"\"\"\nExample project for a Gradle build\nProject name: ${project.name}\n\nMore detailed information here... \"\"\"\n\ntask saygreetings {\n doLast {\n println 'Greetings'\n }\n}\n<\/pre>\nThe command to execute above task is shown below:<\/p>\n
Command<\/em><\/span><\/p>\n
gradle saygreetings\n<\/pre>\n
The output of the command executed is as below:<\/p>\n
Output<\/em><\/span><\/p>\n
apples-MacBook-Air:project bhagvan.kommadi$ gradle saygreetings\n\n> Task :saygreetings\nGreetings\n\nBUILD SUCCESSFUL in 1s\n1 actionable task: 1 executed\n<\/pre>\n
An enterprise application will have multiple projects to be built. The Gradle framework has a root project which can have multiple sub-projects. build. Gradle file has the root project. The file settings.gradle will have the subprojects information.<\/p>\n
For example, you can have the project structure as below:<\/p>\n
- \n
- base_project\n
- \n
- auth<\/li>\n
- usermgmt<\/li>\n
- utils<\/li>\n<\/ul>\n<\/li>\n
- settings.gradle<\/li>\n<\/ul>\n
Based on the project structure, you can have the settings.gradle.<\/p>\n
build.gradle<\/em><\/span><\/p>\n
include 'auth', 'usermgmt', 'utils'\n\n#include 'auth'\n#include 'usermgmt'\n#include 'utils'\n<\/pre>\n
<\/a>2.6 Gradle Tasks<\/h3>\n
The Gradle task is used to create tasks such as jar creation and archive publishing. The Gradle framework is extensible. Tasks are the core part of the framework. A Gradle task can be created for moving data from a directory to the other directory. A task can have a dependency on another task. It can have an input and the output. Gradle has introspection related tasks.
<\/div> <\/div><\/p>\nFor example, the tasks command shows the available tasks for a project. This command shows the base tasks when you do not have a
build.gradle<\/code> file.<\/p>\nTasks command<\/em><\/span><\/p>\n
gradle -q tasks\n<\/pre>\n
The output of the command executed is as below:<\/p>\n
Tasks command output<\/em><\/span><\/p>\n
apples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle -q tasks\n\n------------------------------------------------------------\nTasks runnable from root project\n------------------------------------------------------------\n\nBuild Setup tasks\n-----------------\ninit - Initializes a new Gradle build.\nwrapper - Generates Gradle wrapper files.\n\nHelp tasks\n----------\nbuildEnvironment - Displays all buildscript dependencies declared in root project 'gradlesystem'.\ncomponents - Displays the components produced by root project 'gradlesystem'. [incubating]\ndependencies - Displays all dependencies declared in root project 'gradlesystem'.\ndependencyInsight - Displays the insight into a specific dependency in root project 'gradlesystem'.\ndependentComponents - Displays the dependent components of components in root project 'gradlesystem'. [incubating]\nhelp - Displays a help message.\nmodel - Displays the configuration model of root project 'gradlesystem'. [incubating]\nprojects - Displays the sub-projects of root project 'gradlesystem'.\nproperties - Displays the properties of root project 'gradlesystem'.\ntasks - Displays the tasks runnable from root project 'gradlesystem'.\n\nTo see all tasks and more detail, run gradle tasks --all\n\nTo see more detail about a task, run gradle help --task \n<\/pre>\n
Gradle has helped the task to give information related to the other tasks such as the init task. The command executed for help task related to init is shown below:<\/p>\n
Help for Init task<\/em><\/span><\/p>\n
gradle -q help --task init\n<\/pre>\n
The output of the command executed is as below:<\/p>\n
Help for Init task output<\/em><\/span><\/p>\n
apples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle -q help --task init\nDetailed task information for init\n\nPath\n :init\n\nType\n InitBuild (org.gradle.buildinit.tasks.InitBuild)\n\nOptions\n --dsl Set the build script DSL to be used in generated scripts.\n Available values are:\n groovy\n kotlin\n\n --package Set the package for source files.\n\n --project-name Set the project name.\n\n --test-framework Set the test framework to be used.\n Available values are:\n junit\n junit-jupiter\n kotlintest\n scalatest\n spock\n testng\n\n --type Set the type of project to generate.\n Available values are:\n basic\n cpp-application\n cpp-library\n groovy-application\n groovy-gradle-plugin\n groovy-library\n java-application\n java-gradle-plugin\n java-library\n kotlin-application\n kotlin-gradle-plugin\n kotlin-library\n pom\n scala-library\n\nDescription\n Initializes a new Gradle build.\n\nGroup\n Build Setup\n<\/pre>\n
<\/a>2.7 Gradle Plugins<\/h3>\n
Gradle has an extension for a plugin for preconfigured tasks. It has a base set of plugins and developers can add custom plugins. build.gradle file has plugin specified using the statement apply plugin ‘plugin-name’.<\/p>\n
You can add the entry
apply plugin: 'com.android.application'<\/code> which sets the Android plug-in available for a Gradle build. Gradle has a registry of plugins which can be accessed at site<\/a>.<\/p>\n<\/a>2.8 Gradle Java Project<\/h3>\n
The Gradle framework has features for java projects. You can create a new Gradle based Java project for JUnit Jupiter.<\/p>\n
build.gradle<\/em><\/span><\/p>\n
gradle init --type java-library --test-framework junit-jupiter\n<\/pre>\n
The output of the command executed is as below:<\/p>\n
build.gradle<\/em><\/span><\/p>\n
apples-MacBook-Air:gradlesystem bhagvan.kommadi$ gradle init --type java-library --test-framework junit-jupiter\n\nSelect build script DSL:\n 1: Groovy\n 2: Kotlin\nEnter selection (default: Groovy) [1..2] 1\n\nProject name (default: gradlesystem): junit\nSource package (default: junit): junit\n\n> Task :init\nGet more help with your project: https:\/\/docs.gradle.org\/5.5.1\/userguide\/java_library_plugin.html\n\nBUILD SUCCESSFUL in 50s\n2 actionable tasks: 2 executed\n<\/pre>\n
Java code generated related to the command above is presented below:<\/p>\n
Library class<\/em><\/span><\/p>\n
\/*\n * This Java source file was generated by the Gradle 'init' task.\n *\/\npackage junit;\n\npublic class Library {\n public boolean someLibraryMethod() {\n return true;\n }\n}\n<\/pre>\nThe code generated for Junit Test is shown below:<\/p>\n
Junit class<\/em><\/span><\/p>\n
\/*\n * This Java source file was generated by the Gradle 'init' task.\n *\/\npackage junit;\n\nimport org.junit.jupiter.api.Test;\nimport static org.junit.jupiter.api.Assertions.*;\n\nclass LibraryTest {\n @Test void testSomeLibraryMethod() {\n Library classUnderTest = new Library();\n assertTrue(classUnderTest.someLibraryMethod(), \"someLibraryMethod should return 'true'\");\n }\n}\n<\/pre>\nYou can execute the build using the command below:<\/p>\n
build command<\/em><\/span><\/p>\n
gradle build\n<\/pre>\n
The output of the command executed is presented below:<\/p>\n
build command output<\/em><\/span><\/p>\n
apples-MacBook-Air:junit bhagvan.kommadi$ gradle build\nBUILD SUCCESSFUL in 31s\n4 actionable tasks: 4 up-to-date\n<\/pre>\n
The command for executing the junit test is shown below:<\/p>\n
build command<\/em><\/span><\/p>\n
gradle test\n<\/pre>\n
The output of the command executed is presented below:<\/p>\n
build command output<\/em><\/span><\/p>\n
apples-MacBook-Air:junit bhagvan.kommadi$ gradle test\nBUILD SUCCESSFUL in 35s\n3 actionable tasks: 3 up-to-date\n<\/pre>\n
<\/a>2.9 Gradle Wrapper<\/h3>\n
The Gradle wrapper is used for executing the build with a predefined Gradle version and settings. Gradle version download happens when the Gradle wrapper is executed. The Gradle wrapper can be created using command Gradle wrapper<\/p>\n
gradlew<\/code> is created for mac and Unix systems. gradlew.batis created for window systems. These files are executed when the Gradle command is executed. Gradle wrapper version can be specified in a Gradle task. When the task is executed, Gradle wrapper is created and it downloads the Gradle based on the version. Gradle wrapper version can be specified as shown below:<\/p>\nGradle wrapper<\/em><\/span><\/p>\n
wrapper {\n gradleVersion = '4.9'\n}\n<\/pre>\nGradle options can be specified in the
gradlew<\/code> orgradlew.bat<\/code> file.<\/p>\ngradle wrapper options<\/em><\/span><\/p>\n
#!\/usr\/bin\/env bash\nDEFAULT_JVM_OPTS=\"-Xmx1024m\"\n<\/pre>\n
<\/a>2.10 Gradle Custom Tasks<\/h3>\n
A gradle custom task can be created and it can be derived from other tasks. For example, CopyTask can be created to copy files.<\/p>\n
A copyTask can be created in a
build.gradle<\/code> file as shown below:<\/p>\ncustom task<\/em><\/span><\/p>\n
task copyTask(type: Copy) {\n from 'src'\n into 'dest'\n}\n<\/pre>\nYou can create an src folder inside this project and add an example.txt text file to this folder. copy task will copy the
example.txt<\/code> file to a new dest folder.<\/p>\nThe command to execute above task is shown below:<\/p>\n
custom task run command<\/em><\/span><\/p>\n
gradle copyTask\n<\/pre>\n
The output of the command executed is presented below:<\/p>\n
custom task output<\/em><\/span><\/p>\n
apples-MacBook-Air:customtask bhagvan.kommadi$ gradle copyTask\n\nBUILD SUCCESSFUL in 4s\n1 actionable task: 1 up-to-date\n<\/pre>\n
<\/a>2.11 Gradle Testing<\/h3>\n
Gradle 6.0 has features for unit testing with Junit 5. you can add dependencies in the
build.gradle<\/code> file as shown below.<\/p>\ncustom task<\/em><\/span><\/p>\n
dependencies {\n\n \n testImplementation(enforcedPlatform(\"org.junit:junit-bom:5.4.0\")) \n testImplementation(\"org.junit.jupiter:junit-jupiter\")\n}\n<\/pre>\nGradle test task helps in finding the compiled classes in the project source folder. <\/p>\n
<\/a>2.12 Gradle Deployment<\/h3>\n
Gradle provides support for deploying build artifacts to artifact repositories, such as Artifactory or Sonatype Nexus. You can use a maven-publish plugin for publishing build artifacts.<\/p>\n
<\/a>2.13 Gradle Custom Plugins<\/h3>\n
A gradle custom plugin can be created to have a plugin with custom logic. The build file will have simple and straightforward tasks. The build needs to have declarative logic to have better maintenance.<\/p>\n
<\/a>2.14 Gradle – Eclipse Integration<\/h3>\n
You can find the source code for installing Gradle Plugin using the Grails project in this javacodegeeks article<\/a>.<\/p>\n
You need to also ensure that the Buildship Gradle Integration plugin is installed. The snapshot below shows the installed Gradle version.<\/p>\n
\nEclipse \u2013 Gradle plugin<\/figcaption><\/figure>\n<\/div>\n 2.14.1 Building with Gradle – Eclipse<\/h4>\n
You can import the project HelloWorld which was a Gradle project created. The snapshot below shows the import wizard from the Eclipse menu File-> Import.<\/p>\n
\nEclipse \u2013 Import Gradle Project<\/figcaption><\/figure>\n<\/div>\n After the import, the Gradle Grails project can be viewed in the eclipse. The screen shot below shows the imported project.<\/p>\n
\nGradle Grails Eclipse Project<\/figcaption><\/figure>\n<\/div>\n From the Gradle tasks view, You can see all the Gradle tasks. To execute the grails-app, click on bootRun. The screenshot below shows the Gradle tasks view.<\/p>\n
\nGradle Tasks Eclipse View<\/figcaption><\/figure>\n<\/div>\n The grails app can be accessed at http:\/\/localhost:8080 when the gradle runs the Grails app on eclipse. The snapshot of the Grails app and Gradle task execution is shown below.<\/p>\n
\nGrails App Running \u2013 Eclipse<\/figcaption><\/figure>\n<\/div>\n The
HelloController<\/code> can be accessed and the page renders to show the \u201cGreetings\u201d message. The rendered page is shown below:<\/p>\n\nHello Controller \u2013 Eclipse<\/figcaption><\/figure>\n<\/div>\n Gradle provides several plugins for analyzing the code base of a Gradle project.<\/p>\n
<\/a>2.15 Gradle Build Scans<\/h3>\n
The Gradle project can have a build scanner. A build scan has incidents and details of a Gradle build project. The Gradle remote server will have the build scans which are published. Gradle init is used for creating a project. The command is shown below:<\/p>\n
gradle project create command<\/em><\/span><\/p>\n
gradle init \n<\/pre>\n
You can use build scan option to publish the build scan as shown below:<\/p>\n
- 2.2. Download<\/a><\/dt>\n