add release scripts

.github/prepare-release

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+if [ $# -lt 2 ];
+then
+    echo "usage: $0 <release-version> <new-snapshot-version>" >&2
+    echo "" >&2
+    echo "release-version     : Version of the next release, e.g., 3.1.0" >&2
+    echo "new-snapshot-version: Version of the upcoming nightly releases without the -SNAPSHOT suffix, e.g., 3.2.0" >&2
+    return 1
+fi
+
+git switch -C prepare-release/$1 || exit 1
+
+set_version_and_commit() {
+    ./mvnw versions:set -DnewVersion=$1 -DgenerateBackupPoms=false || return 1
+
+    git add pom.xml || return 1
+    git add "**/pom.xml" 2> /dev/null
+
+    git commit -m "$2" || return 1
+}
+
+set_version_and_commit "$1" "[Release] Version $1"
+set_version_and_commit "$2-SNAPSHOT" "[Release] Update version to $2-SNAPSHOT"

.github/workflows/release.yml

@@ -0,0 +1,73 @@
+name: Release
+
+# workflow triggers
+on:
+  # manually
+  workflow_dispatch:
+  # releases
+  release:
+    types: [published]
+
+jobs:
+  verify:
+    name: Verify build on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+
+    steps:
+    - name: Checkout repository
+      uses: actions/[email protected]
+
+    - name: Setup Java and Maven cache
+      uses: actions/[email protected]
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+        check-latest: true
+        cache: 'maven'
+
+    - name: Verify build
+      run: >
+        ./mvnw clean verify
+        --batch-mode
+        --update-snapshots
+        --no-transfer-progress
+
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    needs: [verify]
+    strategy:
+      fail-fast: true
+
+    steps:
+    - name: Checkout repository
+      uses: actions/[email protected]
+
+    - name: Setup Java and Maven cache
+      uses: actions/[email protected]
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+        check-latest: true
+        cache: 'maven'
+        server-id: ossrh
+        server-username: MAVEN_USERNAME
+        server-password: MAVEN_PASSWORD
+        gpg-private-key: ${{ secrets.OSSRH_GPG_SECRET_KEY }}
+        gpg-passphrase: MAVEN_GPG_PASSPHRASE
+
+    - name: Deploy to staging and release
+      run: >
+        ./mvnw clean deploy -P release
+        -DskipTests
+        --batch-mode
+        --update-snapshots
+        --no-transfer-progress
+      env:
+        MAVEN_USERNAME: ${{ secrets.OSSRH_USERNAME }}
+        MAVEN_PASSWORD: ${{ secrets.OSSRH_TOKEN }}
+        MAVEN_GPG_PASSPHRASE: ${{ secrets.OSSRH_GPG_SECRET_KEY_PASSWORD }}