build-test-cudf-java

name	build-test-cudf-java
description	Build and test cudf Java bindings (cudf-java) inside a cudf devcontainer. Use when the user asks to build, compile, or test Java code in the cudf repository.

Build and Test cudf-java

Prerequisites

JDK and Maven

Ensure JDK (17+) and Maven are installed:

java -version && mvn --version

If either is missing, detect the OS and install using the appropriate package manager. Hints:

• Debian/Ubuntu (apt): sudo apt-get update -qq && sudo apt-get install -y -qq default-jdk maven
• Fedora/RHEL (dnf): sudo dnf install -y java-17-openjdk-devel maven
• Arch (pacman): sudo pacman -S --noconfirm jdk17-openjdk maven
• macOS (brew): brew install openjdk@17 maven

Detect the OS by checking which package manager is available (e.g. command -v apt-get, command -v dnf, etc.) and use the matching command.

Run all Maven commands below from the java/ directory.

Choose a libcudf provider

Prefer the installed nightly package when the changes are limited to Java or JNI and the user has not requested a libcudf source rebuild:

• Build JNI against an installed nightly libcudf, then continue at Running Java tests.

Use a local libcudf source build when the changes affect libcudf, require unreleased libcudf headers or symbols, no compatible nightly exists, or the user explicitly requests a source build:

• Build JNI against a local libcudf build, then continue at Running Java tests.

Running Java tests

Always run mvn install $MVN_COMMON_OPTS -DskipTests first before running tests. The mvn test goal re-triggers the cmake/native build step. If target/cmake-build already contains fully built artifacts from a prior mvn install, this is an incremental no-op. But if the cmake-build directory was cleaned or is missing, mvn test may hit a race condition where the linker tries to link libcudfjni.so before libarrow.a is fully built, causing a cannot find libarrow.a error. If this happens, re-run mvn install $MVN_COMMON_OPTS -DskipTests to rebuild the native code cleanly, then retry mvn test.

All tests

mvn test $MVN_COMMON_OPTS

The POM routes tests that need special assertion or fork behavior to dedicated Surefire executions.

Discovering tests

Java test sources are at src/test/java/ai/rapids/cudf/. Use find or glob to discover test classes:

find src/test/java -name "*Test.java" | head -20

Specific test class

mvn surefire:test@main-tests $MVN_COMMON_OPTS \
  -Dtest="<ClassName>"

Specific test method

mvn surefire:test@main-tests $MVN_COMMON_OPTS \
  -Dtest="<ClassName>#<testName>"

Use the named main-tests execution for specific ordinary tests so -Dtest does not affect the separately configured executions.

Tests with special configuration

Invoke tests that require special configuration through their dedicated executions:

mvn surefire:test@non-empty-null-test $MVN_COMMON_OPTS
mvn surefire:test@fatal-cuda-test $MVN_COMMON_OPTS
mvn surefire:test@native-deps-loader-test $MVN_COMMON_OPTS