The Gradle application plugin extends the language plugins with common application related tasks. It allows running and bundling applications for the jvm.
To use the application plugin, include in your build script:
To define the main-class for the application you have to set the mainClassName
property as shown below
Example 42.2. Configure the application main class
build.gradle
mainClassName = "org.gradle.sample.Main"
Then, you can run the application by running gradle run
. Gradle will take care of building the application classes,
along with their runtime dependencies, and starting the application with the correct classpath.
The plugin can also build a distribution for your application. The distribution will package up the runtime dependencies of the application
along with some OS specific start scripts. All files stored in src/dist
will be added to the root of the
distribution. You can run gradle installApp
to create an image of the application in
build/install/
. You can run projectName
gradle distZip
to create a
ZIP containing the distribution.
The Application plugin adds the following tasks to the project.
Table 42.1. Application plugin - tasks
Task name | Depends on | Type | Description |
run
|
classes
|
JavaExec |
Starts the application. |
startScripts
|
jar
|
CreateStartScripts |
Creates OS specific scripts to run the project as a JVM application. |
installApp
|
jar , startScripts
|
Sync |
Installs the application into a specified directory. |
distZip
|
jar , startScripts
|
Zip |
Creates a full distribution ZIP archive including runtime libraries and OS specific scripts. |
The application plugin adds some properties to the project, which you can use to configure its behaviour. See Project
.
One of the convention properties added by the plugin is applicationDistribution
which is a CopySpec
.
This specification is used by the installApp
and distZip
tasks as the specification of what is to be
include in the distribution. Above copying the starting scripts to the bin
dir and necessary jars to lib
in the distribution, all of the files from the src/dist
directory are also copied. To include any static files in the
distribution, simply arrange them in the src/dist
directory.
If your project generates files to be included in the distribution, e.g. documentation, you can add these files to the distribution by adding to the
applicationDistribution
copy spec.
Example 42.3. Include output from other tasks in the application distribution
build.gradle
task createDocs { def docs = file("$buildDir/docs") outputs.dir docs doLast { docs.mkdirs() new File(docs, "readme.txt").write("Read me!") } } applicationDistribution.from(createDocs) { into "docs" }
By specifying that the distribution should include the task's output files (see Section 15.8.1, “Declaring a task's inputs and outputs”), Gradle knows that the task that produces the files must be invoked before the distribution can be assembled and will take care of this for you.
Example 42.4. Automatically creating files for distribution
Output of gradle distZip
> gradle distZip :createDocs :compileJava :processResources UP-TO-DATE :classes :jar :startScripts :distZip BUILD SUCCESSFUL Total time: 1 secs