Groovy language support for Android
Deprecated: This plugin has been deprecated in favor of Kotlin which has the full support of JetBrains and Google. The changes that go into each Android Plugin Version make it really hard for this plugin to keep up. As of Gradle 6.0 this plugin does not work.
This plugin adds Groovy Language support for Android applications and libraries.
Updates
As of 2.0.0 of this plugin only will work with the Android Gradle Plugin 3.0.0 and above. For support of lower version use 1.2.0.
There is an issues when using build tool 26+ and the Groovy jar. The current work around is to use proguard or to use JarJar to create a jar file that does not have invoke dynamic classes. See ZarZaring the Groovy Jar for Android 26+ to create your own jar and avoid having to run proguard. See Github Issue for more details.
Quick Start
Use a lazybones template from grooid-template
Usage
Edit your build.gradle file to contain the following:
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.0'
classpath 'org.codehaus.groovy:groovy-android-gradle-plugin:2.0.1'
}
}
apply plugin: 'com.android.application'
apply plugin: 'groovyx.android'The latest version of the Groovy Android Plugin can be found here
You must choose which version of Groovy you use. Android support is available in
starting at the 2.4.x releases. You will need to add the following repository to your build.gradle file:
repositories {
jcenter()
}Then you can start using Groovy by adding the groovy dependency with the grooid classifier:
dependencies {
compile 'org.codehaus.groovy:groovy:2.4.12:grooid'
}Full list of releases can be found here here.
Then use the assembleDebug gradle task to test out your build and make sure everything compiles.
Should you want to test development versions of the plugin, you can add the snapshot repository and depend on a SNAPSHOT:
buildscript {
repositories {
jcenter()
maven { url 'http://oss.jfrog.org/artifactory/oss-snapshot-local' }
}
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.0'
classpath 'org.codehaus.groovy:groovy-android-gradle-plugin:2.0.2-SNAPSHOT'
}
}Go here to see what the latest SNAPSHOT version is.
Where to put sources?
Groovy sources may be placed in src/main/groovy, src/test/groovy, src/androidTest/groovy and any src/${buildVariant}/groovy
configured by default. A default project will have the release and debug variants but these can be configured with build
types and flavors. See the android plugin docs
for more about configuring different build variants.
Extra groovy sources may be added in a similar fashion as the android plugin
using the androidGroovy.sourceSets block. This is especially useful for sharing code between the different test types, and also
allows you to add Groovy to an existing project. For example
androidGroovy {
sourceSets {
main {
groovy {
srcDirs += 'src/main/java'
}
}
}
}would add all of the Java files in src/main/java directory to the Groovy
compile task. These files will be removed from the Java compile task,
instead being compiled by GroovyC, and will allow for the Java sources
to be referenced in the Groovy sources (joint compilation).
Please note, that you may need to also add these extra directories to the Java
source sets in the android plugin for Android Studio to recognize the Groovy
files as source.
Writing Groovy Code
This plugin has been successfully tested with Android Studio and will make no attempts to add support for other IDEs.
This plugin will let you write an application in Groovy but it is recommended, for performance, memory and battery life,
that you use @CompileStatic wherever possible.
Details can be found on Melixโs blog and here for more technical details
Including Groovy Libraries
In order to include libraries written in groovy that include the groovy or groovy-all jars, you will need to exclude the groovy dependency allowing the grooid jar to be the one to be compiled against.
For example to use the groovy-xml library you would simply need to do exclude
the group org.codehaus.groovy.
compile ('org.codehaus.groovy:groovy-xml:2.4.3') {
exclude group: 'org.codehaus.groovy'
}Skipping Groovy Compile
As of version 1.2.0 only build types/build flavors with groovy sources included in them will have the groovy compile task added. If you would like to skip the groovy compilation tasks on older versions or on newer version wish to skip them in build types that have groovy sources you can use the following to disable the groovy compiler task.
tasks.whenTaskAdded { task ->
if (task.name == 'compileDebugGroovyWithGroovyc') { # (1)
task.enabled = false
}
}-
Disables groovy compilation only for the debug build type, simply replace
compileDebugGroovyWithGroovycwith whichever compilation task you would like skip to disable it.
Configuring the Groovy compilation options
The Groovy compilation tasks can be configured in the androidGroovy block using the options block:
androidGroovy {
options {
configure(groovyOptions) {
encoding = 'UTF-8'
forkOptions.jvmArgs = ['-noverify'] // maybe necessary if you use Google Play Services
}
}
}See GroovyCompile for more options. See Example Application for an example of using these settings to enable custom compilation options.
Only Use GroovyC
For integration with plain java projects or for working with generated files
(such as BuildConfig) it may be desirable to only have GroovyC run in order to
have Java files reference Groovy files. This is roughly the equivalent of placing
all java source files into the groovy source directory (including auto
generated files like BuildConfig). In order to only have GroovyC run simply set
the flag skipJavaC in the androidGroovy block to true.
androidGroovy {
skipJavaC = true
}Annotation Processing
As of 1.2.0 Release annotation processing is configured by default.
Previous versions would require javaAnnotationProcessing to be set to true.
androidGroovy {
options {
configure(groovyOptions) {
javaAnnotationProcessing = true
}
}
}Android packagingOptions
Groovy Extension Modules and Global transformations both need a file descriptor in order to work. Android packaging has a restriction related to files having the same name located in the same path.
If you are using several Groovy libraries containing extension modules and/or global transformations, Android may complain about those files.
You can simply add the following rule:
android {
packagingOptions {
exclude 'META-INF/services/org.codehaus.groovy.transform.ASTTransformation'
exclude 'META-INF/services/org.codehaus.groovy.runtime.ExtensionModule'
// you may need to exclude other files if you get "duplicate files during packaging of APK"
exclude 'META-INF/groovy-release-info.properties'
exclude 'META-INF/LICENSE'
}
}There are no problems excluding global transformation descriptors because those are only used at compile time, never at runtime.
The problem comes with module extensions. Unless you statically
compile classes using extension modules with @CompileStatic they wonโt
be available at runtime and youโll get a runtime exception.
There is an alternative. The emerger gradle plugin will add excludes for you and merges all extension module descriptors into a single file which will be available at runtime.
Groovy Community
Have questions, want to learn more!? Come ask questions or help others in #android in the Groovy Community Slack groovycommunity.com[Sign-Up Here]