Add checkstyle in maven build

.github/workflows/checkstyle.yml

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+# Copyright (c) 2023-2024, NVIDIA CORPORATION.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# A workflow to java style check
+name: java format check
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Set up JDK
+      uses: actions/setup-java@v4.5.0
+      with:
+        java-version: '8'
+        distribution: 'adopt'
+
+    - uses: actions/checkout@v4
+      with:
+        submodules: true
+        fetch-depth: 0
+
+    - name: Fetch branches and tags
+      run: git fetch --all
+
+    - name: Run checkstyle
+      run: bash ./dev/checkstyle.sh

dev/checkstyle.sh

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+#!/bin/bash
+#
+# Copyright (c) 2024, NVIDIA CORPORATION. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+#!/bin/bash
+
+set -ex
+
+# Assuming you are in the root of your git repository
+MODIFIED_FILES=$(git diff --name-only "origin/${GITHUB_BASE_REF}")
+
+SRC_DIR="src/main/java/"
+TEST_SRC_DIR="src/test/java/"
+# Filter out the Java files that have been modified
+JAVA_FILES=()
+for FILE in $MODIFIED_FILES; do
+  if [[ $FILE == *.java ]]; then
+    if [[ $FILE == $SRC_DIR* ]]; then
+      JAVA_FILES+=("${FILE#"$SRC_DIR"}") # Remove the src/main/java/ prefix
+    elif [[ $FILE == $TEST_SRC_DIR* ]]; then
+      JAVA_FILES+=("${FILE#"$TEST_SRC_DIR"}") # Remove the src/test/java/ prefix
+    fi
+  fi
+done
+
+# If there are Java files to check, run Checkstyle on them
+if [ ${#JAVA_FILES[@]} -ne 0 ]; then
+  mvn checkstyle:check -Dcheckstyle.includes="$(echo "${JAVA_FILES[@]}" | tr ' ' ',')"
+else
+  echo "No Java files modified, skipping Checkstyle."
+fi