Gradle: fixing the gradle wrapper for a Java project


Categories: Development, Java

If the gradle wrapper for your project is broken, you can reinstall it with the “gradle wrapper” command.  For example, below is a common error if you have cloned a git repository where the owner has not pushed all the necessary gradle components into the repo.

$ ./gradlew --info
Error: Could not find or load main class org.gradle.wrapper.GradleWrapperMain

This can be fixed by running the “gradle wrapper” command, but this requires that you have gradle installed first.

Install Gradle

# java required
java --version

# download the latest gradle zip using your browser
# https://gradle.org/releases/

# extract downloaded version
unzip gradle-7.5.1-bin.zip

# add to PATH
export PATH=$PATH:$(realpath gradle-7.5.1/bin)

# smoke test
gradle --version

Fix Gradle wrapper

Fix the gradlew wrapper for the project by changing directory into the project directory and running the “gradle wrapper” task.

# fix gradle wrapper
gradle wrapper

# smoke test gradle wrapper
$ ./gradlew --version
$ ./gradlew tasks

Upgrade Gradle wrapper

If you want to specify an exact version of gradle to use, you can specify a flag.

# upgrade gradle wrapper
gradle wrapper --gradle-version=7.4

# check version
./gradlew --version

 

REFERENCES

gradle download release

stackoverflow, explicitly setting gradle version

Gradle forums, print java version being used

NOTES

Fixing “Cannot lock execution history cache (…) as it has already been locked by this process”

find ~/.gradle -type f -name "*.lock" -delete

Showing the gradle and java version used, from build.gradle

println GradleVersion.current().toString()
println org.gradle.internal.jvm.Jvm.current()

Specifying JVM to use in gradle.properties

org.gradle.java.home=/opt/homebrew/opt/openjdk@21