add GitHub Actions workflow for build and release process

Author: KasperiP

.github/workflows/build-and-release.yml

@@ -0,0 +1,76 @@
+name: Build and Release
+
+on:
+    push:
+        tags:
+            - "v*"
+    workflow_dispatch:
+        inputs:
+            version:
+                description: "Release version (e.g., v1.0.0)"
+                required: true
+                default: "v1.0.0"
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout code
+              uses: actions/checkout@v4
+
+            - name: Set up JDK 22
+              uses: actions/setup-java@v4
+              with:
+                  java-version: "22"
+                  distribution: "temurin"
+
+            - name: Cache Maven dependencies
+              uses: actions/cache@v4
+              with:
+                  path: ~/.m2
+                  key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+                  restore-keys: ${{ runner.os }}-m2
+
+            - name: Build with Maven
+              run: mvn clean package
+
+            - name: Get version from pom.xml
+              id: get_version
+              run: |
+                  VERSION=$(mvn help:evaluate -Dexpression=project.version -q -DforceStdout)
+                  echo "version=$VERSION" >> $GITHUB_OUTPUT
+                  echo "jar_name=lukittu-simple-$VERSION.jar" >> $GITHUB_OUTPUT
+
+            - name: Create Release
+              id: create_release
+              uses: actions/create-release@v1
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+              with:
+                  tag_name: ${{ github.event.inputs.version || github.ref_name }}
+                  release_name: Release ${{ github.event.inputs.version || github.ref_name }}
+                  body: |
+                      ## Changes
+                      - Built from commit ${{ github.sha }}
+
+                      ## Download
+                      Download the JAR file from the assets below.
+                  draft: false
+                  prerelease: false
+
+            - name: Upload JAR to Release
+              uses: actions/upload-release-asset@v1
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+              with:
+                  upload_url: ${{ steps.create_release.outputs.upload_url }}
+                  asset_path: target/${{ steps.get_version.outputs.jar_name }}
+                  asset_name: ${{ steps.get_version.outputs.jar_name }}
+                  asset_content_type: application/java-archive
+
+            - name: Upload JAR as Artifact
+              uses: actions/upload-artifact@v4
+              with:
+                  name: lukittu-simple-jar
+                  path: target/${{ steps.get_version.outputs.jar_name }}