add: ci for java

.github/workflows/ci.yml

@@ -0,0 +1,116 @@
+name: Java CI
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
+    branches:
+      - main
+      - master
+  push:
+    branches:
+      - main
+      - master
+
+jobs:
+  build:
+    name: Build and Test
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        java: [25]
+      fail-fast: false
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: 'temurin'
+          cache: 'gradle'
+
+      - name: Install Ubuntu dependencies
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y cmake build-essential libboost-all-dev
+
+      - name: Install macOS dependencies
+        if: runner.os == 'macOS'
+        run: |
+          brew install cmake boost
+
+      - name: Cache Bitcoin Kernel build
+        uses: actions/cache@v4
+        with:
+          path: |
+            bitcoinkernel/bitcoin/build
+            /usr/local/lib/libbitcoinkernel.*
+          key: ${{ runner.os }}-bitcoinkernel-${{ hashFiles('bitcoinkernel/bitcoin/**') }}
+          restore-keys: |
+            ${{ runner.os }}-bitcoinkernel-
+
+      - name: Build bitcoinkernel
+        run: |
+          cd bitcoinkernel/bitcoin
+          cmake -B build -DBUILD_KERNEL_LIB=ON -DCMAKE_BUILD_TYPE=Release
+          cmake --build build -j$(nproc 2>/dev/null || sysctl -n hw.ncpu)
+          sudo cmake --install build
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+
+      - name: Build with Gradle
+        run: ./gradlew build --no-daemon --stacktrace
+
+      - name: Run tests
+        run: ./gradlew test --no-daemon --stacktrace
+        continue-on-error: false
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-results-${{ matrix.os }}-java${{ matrix.java }}
+          path: |
+            build/reports/tests/
+            build/test-results/
+
+      - name: Upload build artifacts
+        if: success()
+        uses: actions/upload-artifact@v4
+        with:
+          name: build-artifacts-${{ matrix.os }}-java${{ matrix.java }}
+          path: build/libs/
+
+  code-quality:
+    name: Code Quality Checks
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up JDK 25
+        uses: actions/setup-java@v4
+        with:
+          java-version: 25
+          distribution: 'temurin'
+          cache: 'gradle'
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+
+      - name: Run checkstyle (if configured)
+        run: ./gradlew checkstyleMain checkstyleTest --no-daemon
+        continue-on-error: true
+
+      - name: Run spotbugs (if configured)
+        run: ./gradlew spotbugsMain --no-daemon