diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index 27195b379a61..24124593337b 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -568,36 +568,20 @@ jobs:
     permissions:
       actions: read
       contents: read
+      id-token: write
       packages: read
+      pull-requests: read
+    secrets: inherit # zizmor: ignore[secrets-inherit]
+    uses: rapidsai/shared-workflows/.github/workflows/custom-job.yaml@main
     strategy:
       fail-fast: false
       matrix: ${{ fromJSON(needs.java-build-matrix.outputs.matrix) }}
-    runs-on: linux-${{ matrix.ARCH }}-gpu-l4-latest-1
-    container:
-      image: rapidsai/ci-wheel:26.10-cuda${{ matrix.CUDA_VER }}-${{ matrix.LINUX_VER }}-py${{ matrix.PY_VER }} # zizmor: ignore[unpinned-images]
-      env:
-        NVIDIA_VISIBLE_DEVICES: ${{ env.NVIDIA_VISIBLE_DEVICES }}
-    defaults:
-      run:
-        shell: bash
-    steps:
-      - name: Checkout
-        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
-        with:
-          persist-credentials: false
-      - name: Download java-build artifact
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
-        with:
-          name: cudf_java_${{ matrix.ARCH }}_cu${{ matrix.CUDA_MAJOR }}
-          path: java_pkg
-      - name: Run Java tests
-        env:
-          LIBCUDF_LARGE_STRINGS_ENABLED: "0"
-        run: |
-          . java/ci/java_classifier.sh
-          JAVA_JAR="$(cudf_java_resolve_artifact_jar java_pkg)"
-          export JAVA_JAR
-          ci/test_packaged_java.sh
+    with:
+      build_type: pull-request
+      arch: ${{ matrix.ARCH }}
+      node_type: "gpu-l4-latest-1"
+      container_image: "rapidsai/ci-wheel:26.10-cuda${{ matrix.CUDA_VER }}-${{ matrix.LINUX_VER }}-py${{ matrix.PY_VER }}"
+      script: "ci/test_packaged_java.sh"
   conda-notebook-tests:
     needs: [conda-python-build, conda-python-build-noarch, changed-files]
     permissions:
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 9ef2847a6dc2..1aaf1bdecda0 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -161,6 +161,37 @@ jobs:
       arch: "amd64"
       container_image: "rapidsai/ci-conda:26.10-latest"
       script: "ci/test_java.sh"
+  # Test the packaged cuDF Java JAR built by build.yaml java-build for every Maven classifier.
+  java-build-matrix:
+    permissions:
+      contents: read
+    uses: rapidsai/shared-workflows/.github/workflows/compute-matrix.yaml@main
+    with:
+      build_type: ${{ inputs.build_type }}
+      matrix_name: conda-cpp-build
+      matrix_filter: 'map(. + {CUDA_MAJOR: (.CUDA_VER | split(".") | .[0])})'
+  java-tests:
+    needs: [java-build-matrix]
+    permissions:
+      actions: read
+      contents: read
+      id-token: write
+      packages: read
+      pull-requests: read
+    secrets: inherit # zizmor: ignore[secrets-inherit]
+    uses: rapidsai/shared-workflows/.github/workflows/custom-job.yaml@main
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJSON(needs.java-build-matrix.outputs.matrix) }}
+    with:
+      build_type: ${{ inputs.build_type }}
+      branch: ${{ inputs.branch }}
+      date: ${{ inputs.date }}
+      sha: ${{ inputs.sha }}
+      arch: ${{ matrix.ARCH }}
+      node_type: "gpu-l4-latest-1"
+      container_image: "rapidsai/ci-wheel:26.10-cuda${{ matrix.CUDA_VER }}-${{ matrix.LINUX_VER }}-py${{ matrix.PY_VER }}"
+      script: "ci/test_packaged_java.sh"
   conda-notebook-tests:
     permissions:
       actions: read
diff --git a/ci/test_packaged_java.sh b/ci/test_packaged_java.sh
index dd5c1394413f..22d8f2738b76 100755
--- a/ci/test_packaged_java.sh
+++ b/ci/test_packaged_java.sh
@@ -5,11 +5,15 @@
 # Run the Java tests against an already-packaged classifier JAR.
 #
 # Activates -Ppackaged-jar-tests so the surefire classpath uses the JAR at
-# JAVA_JAR instead of a locally compiled target/classes tree. Caller places
-# the JAR (e.g. via actions/download-artifact) before invoking this script.
+# JAVA_JAR instead of a locally compiled target/classes tree.
+#
+# When JAVA_JAR is unset, download the java-build artifact via
+# rapids-download-from-github (pr.yaml for PRs, build.yaml otherwise).
 #
 # Inputs (environment variables):
-#   JAVA_JAR                       Absolute path to the classifier JAR (required).
+#   JAVA_JAR                       Optional. Absolute path to the classifier JAR.
+#                                  If unset, the JAR is downloaded from the
+#                                  matching java-build artifact.
 #   LIBCUDF_LARGE_STRINGS_ENABLED  Optional; defaults to 0 (same as ci/test_java.sh).
 
 set -euo pipefail
@@ -17,8 +21,34 @@ set -euo pipefail
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "${REPO_ROOT}"
 
-if [[ -z ${JAVA_JAR:-} || ! -f ${JAVA_JAR} ]]; then
-  echo "Error: JAVA_JAR must point to an existing classifier JAR" >&2
+# shellcheck disable=SC1091
+. "${REPO_ROOT}/java/ci/java_classifier.sh"
+
+if [[ -z ${JAVA_JAR:-} ]]; then
+  if [[ -z ${RAPIDS_CUDA_VERSION:-} ]]; then
+    echo "Error: RAPIDS_CUDA_VERSION must be set when JAVA_JAR is unset" >&2
+    exit 1
+  fi
+  cuda_major="${RAPIDS_CUDA_VERSION%%.*}"
+
+  # matrix.ARCH values are amd64/arm64; $(arch) / uname -m return x86_64/aarch64.
+  case "$(uname -m)" in
+    x86_64)  java_arch=amd64 ;;
+    aarch64|arm64) java_arch=arm64 ;;
+    *)
+      echo "Error: unsupported host arch '$(uname -m)'" >&2
+      exit 1
+      ;;
+  esac
+
+  rapids-logger "Downloading cudf_java_${java_arch}_cu${cuda_major}"
+  JAVA_PKG="$(rapids-download-from-github "cudf_java_${java_arch}_cu${cuda_major}")"
+  JAVA_JAR="$(cudf_java_resolve_artifact_jar "${JAVA_PKG}")"
+  export JAVA_JAR
+fi
+
+if [[ ! -f ${JAVA_JAR} ]]; then
+  echo "Error: JAVA_JAR='${JAVA_JAR}' does not point to an existing file" >&2
   exit 1
 fi