To create the Gradle Wrapper batch and shell scripts, we can invoke the built-in wrapper task. This task is already available if we have installed Gradle on our computer. Let's invoke the wrapper task from the command-line:

$ gradle wrapper
:wrapper
BUILD SUCCESSFUL
Total time: 0.61 secs

After the execution of the task, we have two script files—€”gradlew.bat and gradlew—€”in the root of our project directory. These scripts contain all the logic needed to run Gradle. If Gradle is not downloaded yet, the Gradle distribution will be downloaded and installed locally.

In the gradle/wrapper directory, relative to our project directory, we find the gradle-wrapper.jar and gradle-wrapper.properties files. The gradle-wrapper.jar file contains a couple of class files necessary to download and invoke Gradle. The gradle-wrapper.properties file contains settings, such as the URL, to download Gradle. The gradle-wrapper.properties file also contains the Gradle version number. If a new Gradle version is released, we only have to change the version in the gradle-wrapper.properties file and the Gradle Wrapper will download the new version so that we can use it to build our project.

All the generated files are now part of our project. If we use a version control system, then we must add these files to the version control. Other people that check out our project can use the gradlew scripts to execute tasks from the project. The specified Gradle version is downloaded and used to run the build file.

If we want to use another Gradle version, we can invoke the wrapper task with the --gradle-version option. We must specify the Gradle version that the Wrapper files are generated for. By default, the Gradle version that is used to invoke the wrapper task is the Gradle version used by the wrapper files.

To specify a different download location for the Gradle installation file, we must use the --gradle-distribution-url option of the wrapper task. For example, we could have a customized Gradle installation on our local intranet, and with this option, we can generate the Wrapper files that will use the Gradle distribution on our intranet.

In the following example, we generate the wrapper files for Gradle 2.12 explicitly:

$ gradle wrapper --gradle-version=2.12
:wrapper
BUILD SUCCESSFUL
Total time: 0.61 secs

If we want to customize properties of the built-in wrapper task, we must add a new task to our Gradle build file with the org.gradle.api.tasks.wrapper.Wrapper type. We will not change the default wrapper task, but create a new task with new settings that we want to apply. We need to use our new task to generate the Gradle Wrapper shell scripts and support files.

We can change the names of the script files that are generated with the scriptFile property of the Wrapper task. To change the name and location of the generated JAR and properties files, we can change the jarFile property:

task createWrapper(type: Wrapper) { 
    // Set Gradle version for wrapper files. 
    gradleVersion = '2.12' 
 
    // Rename shell scripts name to 
    // startGradle instead of default gradlew. 
    scriptFile = 'startGradle' 
 
    // Change location and name of JAR file 
    // with wrapper bootstrap code and 
    // accompanying properties files. 
    jarFile = "${projectDir}/gradle-bin/gradle-bootstrap.jar" 
} 

If we run the createWrapper task, we get a Windows batch file and shell script and the Wrapper bootstrap JAR file with the properties file is stored in the gradle-bin directory:

$ gradle createWrapper
:createWrapper
BUILD SUCCESSFUL
Total time: 0.605 secs
$ tree .
.
├── gradle-bin
│ ├── gradle-bootstrap.jar
│ └── gradle-bootstrap.properties
├── startGradle
├── startGradle.bat
└── build.gradle
2 directories, 5 files

To change the URL from where the Gradle version must be downloaded, we can alter the distributionUrl property. For example, we could publish a fixed Gradle version on our company intranet and use the distributionUrl property to reference a download URL on our intranet. This way we can make sure that all developers in the company use the same Gradle version:

task createWrapper(type: Wrapper) { 
    // Set URL with custom Gradle distribution. 
    distributionUrl = 'http://intranet/gradle/dist/gradle-custom-       2.12.zip' 
}