:heavy_exclamation_mark: Important: This section contains tips for developers who are maintaining the
flink-training
project (not so much people doing the training).
The following sections apply on top of the Setup Instructions above.
Just like Apache Flink, we use the Spotless plugin together with google-java-format to format our Java code. You can configure your IDE to automatically apply formatting upon saving with these steps:
.*\.java
. Otherwise, you will get unintended reformatting in other files you edit.We use the Spotless plugin for formatting Scala code as well and apply a formatting style similar to the Scalastyle configuration from Apache Flink. The code style is verified during ./gradlew check
which will also print instructions how to fix the style if it does not comply with the defined format.
There is a list of refactoring commits in .git-blame-ignore-revs
. When looking at change annotations using git blame
, it is helpful to ignore these. You can configure git and your IDE to do so with:
git config blame.ignoreRevsFile .git-blame-ignore-revs
To add a new exercise, we recommend copying an existing one and adapting it. Make sure the new subproject's build.gradle
file contains appropriate class name properties so that we can create the right tasks for running tests and solutions on the command line.
For example:
ext.javaExerciseClassName = 'org.apache.flink.training.exercises.ridesandfares.RidesAndFaresExercise' ext.scalaExerciseClassName = 'org.apache.flink.training.exercises.ridesandfares.scala.RidesAndFaresExercise' ext.javaSolutionClassName = 'org.apache.flink.training.solutions.ridesandfares.RidesAndFaresSolution' ext.scalaSolutionClassName = 'org.apache.flink.training.solutions.ridesandfares.scala.RidesAndFaresSolution' apply plugin: 'application' mainClassName = ext.javaExerciseClassName
./gradlew clean check shadowJar ./gradlew clean check shadowJar --no-build-cache
./gradlew cleanTest test --no-build-cache
:information_source: Note: Ignoring the build-cache is required if you really want to run the test again (without any changes in code). Otherwise the test tasks will just pull the latest test results from the cache.
./gradlew spotlessApply ./gradlew :rides-and-fares:spotlessApply
:information_source: Note: You do not have to remember this since
./gradlew check
will not only verify the formatting and print any errors but also tell you the command to use to fix these.
Add the following code to the subprojects { /*...*/ }
section of the build.gradle
file and adapt accordingly. For example:
tasks.withType(JavaCompile) { options.compilerArgs << '-Xlint:unchecked' options.deprecation = true }
:information_source: Note: We do not add this by default to keep the training requirements low for participants and focus on the exercises.
You may see this warning being reported from Gradle:
Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.
You can use ‘--warning-mode all’ to show the individual deprecation warnings and determine if they come from your own scripts or plugins.
See https://docs.gradle.org/7.1/userguide/command_line_interface.html#sec:command_line_warnings
This is currently caused by https://github.com/johnrengelman/shadow/issues/680 and has to be fixed by the shadow plugin developers.