Fix exception "new request handling", tie beans to the lifecycle of Vaadin Flow routing components; PreserveOnRefresh is not necessaary

.dockerignore

@@ -0,0 +1,8 @@
+/.gradle/
+/.idea/
+/.pybuilder/
+/build/
+/doc/
+.gitignore
+gradlew.bat
+

.gitignore

@@ -1,4 +1,5 @@
 build/
 .gradle/
 .idea/
-frontend/generated/
+frontend/generated/
+__pycache__/

.gitlab-ci.yml

@@ -0,0 +1,70 @@
+stages:
+#  - test
+#  - buildjar
+  - buildimage
+#  - publish
+
+variables:
+  CACHE_FALLBACK_KEY: fallback-key
+
+.img: &img
+  image: openjdk:22-jdk-slim
+  cache:
+    - key: ${CI_COMMIT_REF_SLUG}
+      fallback_keys:
+        - cache-$CI_DEFAULT_BRANCH
+        - cache-default
+    - paths:
+        - /var/cache/apt
+        - .gradle/wrapper
+        - .gradle/caches
+  before_script:
+    - echo "___________________START_before_script________________________"
+    - echo ${CI_COMMIT_REF_SLUG}
+    - apt-get update && apt-get -qqy upgrade
+
+#test:
+#  <<: *img
+#  stage: test
+#  script:
+#    - ./gradlew test
+
+#buildjar:
+#  <<: *img
+#  stage: buildjar
+#  cache:
+#    - key: ${CI_COMMIT_REF_SLUG}
+#  script:
+#    - ./gradlew clean build -Pvaadin.productionMode
+#  artifacts:
+#    name: "ModeratorElection"
+#    paths:
+#      - build/libs/
+#    expire_in: 1 week
+
+buildimage:
+  stage: buildimage
+  image: docker:latest
+  services:
+    - docker:dind
+  cache:
+    - key: ${CI_COMMIT_REF_SLUG}
+#  dependencies:
+#    - buildjar
+  before_script:
+    - echo "---------- BEFORE -------------"
+#    - echo "$CI_REGISTRY_PASSWORD" | docker login $CI_REGISTRY --username $CI_REGISTRY_USER --password-stdin
+    - docker login -u $DOCKERHUB_USER -p $DOCKERHUB_PASSWORD
+  script:
+    - export DOCKER_BUILDKIT=1
+    - docker build --tag=$DOCKERHUB_USER/moderator-election-vaadin_fullstack:latest --target=ci-image-stage --build-arg BUILDKIT_INLINE_CACHE=1 .
+    - docker push $DOCKERHUB_USER/moderator-election-vaadin_fullstack
+
+#  stage: image
+#  script:
+
+#publish:
+#  stage: publish
+#- export IMAGE_DOCKERHUB_USER=$DOCKERHUB_USER
+#- export IMAGE_DOCKERHUB_PASSWORD=$DOCKERHUB_PASSWORD
+

Dockerfile

@@ -0,0 +1,41 @@
+#buildJar-stage
+FROM openjdk:22-jdk-slim as build-jar-stage
+
+RUN \
+    --mount=type=cache,target=/var/cache/apt \
+    apt-get update && apt-get -qqy upgrade
+ADD ./ /usr/local/src/ModeratorElection
+WORKDIR /usr/local/src/ModeratorElection/
+RUN ./gradlew build -Pvaadin.productionMode
+
+# Run jar stage
+FROM build-jar-stage AS run-jar-stage
+EXPOSE 8080
+WORKDIR /usr/local/src/ModeratorElection/build/libs/
+RUN chmod 0740 ./ModeratorElection.jar
+ENTRYPOINT ["java", "-jar", "./ModeratorElection.jar"]
+
+FROM build-jar-stage AS ci-image-stage
+RUN chmod 0740 ./build/libs/ModeratorElection.jar
+ENTRYPOINT ["java", "-jar", "./build/libs/ModeratorElection.jar"]
+
+#build-native-stage
+FROM ubuntu:latest as build-native-stage
+
+ADD image/resources /tmp
+RUN \
+    --mount=type=cache,target=/var/cache/apt \
+    /tmp/install.sh
+ENV LANG=en_US.UTF-8 \
+    JAVA_HOME=/usr/lib/jvm/graalvm/bin
+
+# Run native binary stage
+FROM build-native-stage AS run-native-stage
+
+EXPOSE 8080
+#CMD ["mkdir /usr/local/src/ModeratorElection"]
+WORKDIR /usr/local/src/ModeratorElection/build/native/nativeCompile/
+##copy native binary
+#COPY --from=buildNative-stage /usr/local/src/ModeratorElection/build/native/nativeCompile/ .
+RUN chmod 0740 ./ModeratorElection
+ENTRYPOINT ["./ModeratorElection"]

README.md

@@ -0,0 +1,48 @@
+# meapp-fullstack: ModeratorElection
+
+## Purpose
+
+**ModeratorElection** provides a fullstack java app development as **graalvm binary** containing:
+* Java app to elect a team member from a comma separated list delivered by environment variable
+* Backend Spring Boot embeded Tomcat<sup>®</sup> Server
+* Frontend Vaadin Framework
+* Dockerfile to generate multi stage image,   
+  first stage compilation to graalvm binary, second stage as run stage - graalvm binary execution
+
+## Try out
+Development phase is completed, we will deploy production soon - reachable at  
+https://meapp-fullstack.jitsi.prod.meissa.de
+
+## Setup
+* in **IDE development**, run  
+    `./gradlew clean vaadinPrepareFrontend`
+* build **jar file**  
+`./gradlew clean build -Pvaadin.productionMode`  
+-> output jar to build/libs/
+* compile **native-image graalvm binary**  
+  (1) use graalvm agent to announce project dependencies
+```shell
+MEMBERNAMES=er,sie,es java -agentlib:native-image-agent=config-output-dir=src/main/resources/META-INF/native-image -jar build/libs/ModeratorElection-0.0.1-SNAPSHOT.jar
+```  
+  (2)
+`./gradlew nativeCompile -Dvaadin.productionMode=true`  
+-> output binary and necessary libs to build/native/nativeCompile/
+* **py builder/build.py** usage recommendation:  
+`pyb <task>` to either create docker image, publish docker image, run test  or dry run.  
+py builder is using **meissa PyPi package ddadevops** for smart deployment.
+
+## Get help
+`./gradlew tasks`
+
+## Development & mirrors
+
+Development completed at:   
+https://repo.prod.meissa.de/meissa/ModeratorElection   
+
+Mirror:  
+https://gitlab.com/domaindrivenarchitecture/ModeratorElection (CI)
+
+## License
+
+Copyright © 2024 meissa GmbH
+Licensed under the [Apache License, Version 2.0](LICENSE)

build.gradle

@@ -6,11 +6,14 @@ buildscript {
 		}
 }
 plugins {
-	id 'org.springframework.boot' version '3.1.5'
-	id 'io.spring.dependency-management' version '1.0.15.RELEASE'
+	id 'org.springframework.boot' version '3.3.1'
+	id 'io.spring.dependency-management' version '1.1.6'
 	id 'java'
-	id 'com.vaadin'
+	id 'com.vaadin' version '24.4.4'
+	id 'org.graalvm.buildtools.native' version '0.10.2'
 }
+group = 'com.ModeratorElection'
+//version = '0.0.1-SNAPSHOT'
 
 repositories {
 	mavenCentral()
@@ -19,6 +22,10 @@ repositories {
 	maven { setUrl("https://maven.vaadin.com/vaadin-addons") }
 }
 
+ext {
+	set('vaadinVersion', '24.4.4')
+}
+
 configurations {
 	developmentOnly
 	runtimeClasspath {
@@ -27,11 +34,13 @@ configurations {
 }
 
 dependencies {
-	implementation('com.vaadin:vaadin-spring-boot-starter')
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'com.vaadin:vaadin-spring-boot-starter'
 	developmentOnly 'org.springframework.boot:spring-boot-devtools'
 	testImplementation('org.springframework.boot:spring-boot-starter-test') {
 		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
 	}
+	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
 dependencyManagement {
@@ -40,6 +49,47 @@ dependencyManagement {
 	}
 }
 
-test{
+tasks.named('test') {
 	useJUnitPlatform()
-}
+	jvmArgs "-Xshare:off"
+}
+
+java {
+	toolchain {
+		languageVersion = JavaLanguageVersion.of(22)
+	}
+}
+
+graalvmNative {
+	binaries {
+        main {
+			mainClass = 'com.ModeratorElection.MEApplication'
+			buildArgs.add("-march=native")
+			buildArgs.add("-R:MaxHeapSize=6442450944")
+			fallback = false
+            imageName.set('ModeratorElection')
+			//javaLauncher @JavaExec :: Configures the java executable to be used to run the tests.
+			javaLauncher.set(javaToolchains.launcherFor {
+        		languageVersion.set(JavaLanguageVersion.of(22))
+        		//vendor.set(JvmVendorSpec.GRAAL_VM)
+			})
+        }
+    }
+    testSupport = false
+	toolchainDetection = false
+}
+
+/*tasks.withType(JavaCompile) {
+    options.compilerArgs += ['-Xlint:deprecation']
+	//,'-Xlint:unchecked'
+}*/
+
+/*
+task runApp(type: JavaExec) {
+  classpath = sourceSets.main.runtimeClasspath
+
+  mainClass = 'package.Main'
+
+  // arguments to pass to the application
+  args 'membernames'
+}*/

build.py

@@ -0,0 +1,56 @@
+from os import environ
+from subprocess import run
+from datetime import datetime
+from pybuilder.core import task, init
+from ddadevops import *
+
+name = 'moderator-election'
+MODULE = ''
+PROJECT_ROOT_PATH = '../..'
+version = "0.0.1-dev"
+
+@init
+def initialize(project):
+    image_tag = version
+    if "dev" in image_tag:
+        image_tag += datetime.now().strftime("%Y-%m-%d-%H-%M-%S")
+
+    input = {
+        "name": name,
+        "module": "vaadin_fullstack",
+        "stage": "notused",
+        "project_root_path": PROJECT_ROOT_PATH,
+        "build_types": ["IMAGE"],
+        "mixin_types": [],
+        "image_naming": "NAME_AND_MODULE",
+        "image_tag": f"{image_tag}",
+    }
+
+    project.build_depends_on("ddadevops>=4.7.0")
+
+    build = DevopsImageBuild(project, input)
+    build.initialize_build_dir()
+
+
+@task
+def image(project):
+    build = get_devops_build(project)
+    build.image()
+
+@task
+def drun(project):
+    build = get_devops_build(project)
+    build.drun()
+
+
+@task
+def test(project):
+    build = get_devops_build(project)
+    run("./gradlew test", shell=True, check=True)
+
+
+@task
+def publish(project):
+    build = get_devops_build(project)
+    build.dockerhub_login()
+    build.dockerhub_publish()

doc/dev_notes.md

@@ -0,0 +1,106 @@
+### ToDo  
+
+```
+HowTo BUILD jar?
+
+Failed within local: ./gradle build
+java -jar build/libs/ModeratorElection.jar -> localhost:6333 "White Label..."-Error
+
+=> ./gradlew clean build -Pvaadin.productionMode
+..in ide dev: ./gradlew clean vaadinPrepareFrontend
+```
+
+```
+-x processTestAot - exclude, skip tests
+
+https://docs.spring.io/spring-boot/gradle-plugin/aot.html
+Processing Tests
+The AOT engine can be applied to JUnit 5 tests that use Spring’s Test Context Framework. 
+Suitable tests are processed by the 'processTestAot' task to generate 
+'ApplicationContextInitializer' code. As with application AOT processing, the 'BeanFactory' 
+is fully prepared at build-time. As with 'processAot', the 'processTestAot' task is 'JavaExec' 
+subclass and can be configured as needed to influence this processing.
+The 'nativeTest' task of the GraalVM Native Image plugin is automatically configured to 
+use the output of the 'processAot' and 'processTestAot' tasks.
+```
+
+```
+For production:
+* install.sh 
+    git clone --single-branch --branch main https://repo.prod.meissa.de/meissa/ModeratorElection.git /usr/local/src/ModeratorElection
+     
+```
+
+```
+build graalvm binary
+1. First build jar locally, and get META-INF with   
+    ./gradlew clean build -Pvaadin.productionMode -x processTestAot
+    MEMBERNAMES=er,sie,es java -agentlib:native-image-agent=config-output-dir=src/main/resources/META-INF/native-image -jar build/libs/ModeratorElection-0.0.1-SNAPSHOT.jar 
+    curl -X GET localhost:8080 
+2. graalvm native-image compilation
+    ./gradlew nativeCompile -Dvaadin.productionMode=true //-H:ConfigurationFileDirectories=/path/to/config-dir/ notwendig falls nicht in src/main/resources/META-INF/native-image/
+```
+
+```
+Dockerizing -> image/Dockerfile  
+
+install buildx-plugin by binary to use build-native-stage only with DOCKER_BUILDKIT:  
+- https://github.com/docker/buildx/releases/download/v0.15.1/buildx-v0.15.1.linux-amd64
+- sha256sum buildx-v0.15.1.linux-amd64
+- move to file: mv buildx-v0.15.1.linux-amd64 $HOME/.docker/cli-plugins/docker-buildx  
+- chmod x $HOME/.docker/cli-plugins/docker-buildx 
+
+further:  
+    It could be either build jar file or graalvm binary  
+    
+    (1)build-jar-stage  
+    docker build --tag=meapp-jar --target=build-jar-stage .
+    (2)ENTRYPOINT as run-jar-stage
+    docker build --tag=run-meapp-jar --target=run-jar-stage
+    
+    (3)build-native-stage  
+    DOCKER_BUILDKIT=1 docker build --tag=meapp-native --target= build-native-stage .
+    (4)ENTRYPOINT as run-native-stage
+    DOCKER_BUILDKIT=1 docker build --tag=meapp-run-native --target=run-native-stage .
+    
+Test images:  
+    docker run -e MEMBERNAMES=er,sie,es -p 8080:8080 run-jar-stage:latest
+    docker run -e MEMBERNAMES=er,sie,es -p 8080:8080 run-native-stage:latest
+
+Buildkit caching:
+    export DOCKER_BUILDKIT=1
+    --build-arg BUILDKIT_INLINE_CACHE=1
+    (1)docker build --tag=meapp-jar --target=build-jar-stage --build-arg BUILDKIT_INLINE_CACHE=1 .
+    (2)docker build --tag=moderator-election-vaadin_fullstack --target=run-jar-stage --build-arg BUILDKIT_INLINE_CACHE=1 .
+    (3)docker build --tag=meapp-native --target=build-native-stage --build-arg BUILDKIT_INLINE_CACHE=1 .
+    (4)docker build --tag=meapp-run-native --target=run-native-stage --build-arg BUILDKIT_INLINE_CACHE=1 .
+
+
+
+```
+
+```
+gu available
+https://docs.oracle.com/en/graalvm/enterprise/21/docs/reference-manual/graalvm-updater/#component-installation
+```
+
+```  
+vaadin 24.3.3, after npm audit fix during image build: 
+npm warn deprecated workbox-google-analytics@7.0.0: It is not compatible with newer versions of GA starting with v4, as long as you are using GAv3 it should be ok, but the package is not longer being maintained  
+npm warn deprecated sourcemap-codec@1.4.8: Please use @jridgewell/sourcemap-codec instead  
+npm warn deprecated inflight@1.0.6: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.  
+npm warn deprecated rollup-plugin-terser@7.0.2: This package has been deprecated and is no longer maintained. Please use @rollup/plugin-terser  
+npm warn deprecated glob@7.2.3: Glob versions prior to v9 are no longer supported
+```
+
+```
+Refresh, Singleton Issue
+https://github.com/vaadin/flow/issues/9376
+https://mvysny.github.io/cant-move-node/
+https://vaadin.com/forum/t/unregistered-node-was-not-found-based-on-its-id-the-tree-is-most-likely-co/161068
+https://vaadin.com/docs/v14/flow/integrations/spring/tutorial-spring-scopes
+    => @PreserveOnRefresh annotation in MainView.java does the trick
+```
+```
+ddadevops anpassung, dass src code ins docker image übergeben werden kann - ohne git clone
+```

frontend/index.html

@@ -3,7 +3,7 @@
 This file is auto-generated by Vaadin.
 -->
 
-<html lang="en">
+<html>
 <head>
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1" />

gradle.properties

@@ -1 +1 @@
-vaadinVersion=24.3.13
+vaadinVersion=24.4.4

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

image/resources/install.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+
+set -exo pipefail
+
+function main()
+{
+    #upgradeSystem
+    apt-get update && apt-get -qqy upgrade
+    apt-get -qqy install curl git build-essential libz-dev zlib1g-dev
+
+    #change to main branch for production
+    #change to MEapp-development branch for development
+    git clone --single-branch --branch main https://repo.prod.meissa.de/meissa/ModeratorElection.git /usr/local/src/ModeratorElection
+
+    #download gradle
+    #gradle_version="8.4"
+    #curl -SsLo /tmp/gradle-${gradle_version}-bin.zip https://services.gradle.org/distributions/gradle-${gradle_version}-bin.zip
+    #curl -SsLo /tmp/gradle-${gradle_version}-bin.zip.sha256 https://services.gradle.org/distributions/gradle-${gradle_version}-bin.zip.sha256
+
+    #download graalvm
+    #graalvm-community-jdk, v22.0.1 2024-04-16
+    graalvm_jdk_version="22.0.1"
+    curl -SsLo /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-22.0.1/graalvm-community-jdk-22.0.1_linux-x64_bin.tar.gz
+    curl -SsLo /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz.sha256 https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-${graalvm_jdk_version}/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz.sha256
+
+    #checksum graalvm
+    checksum
+
+    #install graalvm
+    graalvm_inst
+
+    #nativeCompile
+    buildproc
+
+    #cleanupDocker
+    rm -f /root/.ssh/authorized_keys
+    rm -f /root/.ssh/authorized_keys2
+
+    apt-get clean
+    apt-get -qqy autoremove --purge
+    apt-get -qqy autoclean
+    rm -rf /var/lib/apt/lists/
+
+    rm -rf /tmp/*
+
+    find /var/cache -type f -exec rm -rf {} \;
+    find /var/log/ -name '*.log' -exec rm -f {} \;
+
+} > /dev/null
+
+function checksum() {
+    #graalvm
+    echo "  /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz"|tee -a /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz.sha256
+    sha256sum -c --status /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz.sha256
+}
+
+function graalvm_inst(){
+    mkdir /usr/lib/jvm/
+    tar -C /usr/lib/jvm/ -xzf /tmp/graalvm-community-jdk-${graalvm_jdk_version}_linux-x64_bin.tar.gz
+    dirname_graalvm=$(ls /usr/lib/jvm/|grep -e graa)
+    mkdir /usr/lib/jvm/graalvm/
+    ln -s /usr/lib/jvm/$dirname_graalvm/bin/ /usr/lib/jvm/graalvm/
+    update-alternatives --install /usr/bin/java java /usr/lib/jvm/graalvm/bin/java 0
+    echo "export PATH=$PATH:/usr/lib/jvm/graalvm/bin"| tee -a ~/.bashrc
+}
+
+function buildproc() {
+    cd /usr/local/src/ModeratorElection/
+    #build graalvm binary
+    ./gradlew nativeCompile -Dvaadin.productionMode=true -x processTestAot
+}
+
+#source /tmp/install_functions_debian.sh
+DEBIAN_FRONTEND=noninteractive DEBCONF_NOWARNINGS=yes main
+
+
+

package.json

@@ -4,248 +4,102 @@
   "type": "module",
   "dependencies": {
     "@polymer/polymer": "3.5.1",
-    "@vaadin/a11y-base": "24.3.13",
-    "@vaadin/accordion": "24.3.13",
-    "@vaadin/app-layout": "24.3.13",
-    "@vaadin/avatar": "24.3.13",
-    "@vaadin/avatar-group": "24.3.13",
-    "@vaadin/bundles": "24.3.13",
-    "@vaadin/button": "24.3.13",
-    "@vaadin/checkbox": "24.3.13",
-    "@vaadin/checkbox-group": "24.3.13",
-    "@vaadin/combo-box": "24.3.13",
+    "@vaadin/bundles": "24.4.0",
     "@vaadin/common-frontend": "0.0.19",
-    "@vaadin/component-base": "24.3.13",
-    "@vaadin/confirm-dialog": "24.3.13",
-    "@vaadin/context-menu": "24.3.13",
-    "@vaadin/custom-field": "24.3.13",
-    "@vaadin/date-picker": "24.3.13",
-    "@vaadin/date-time-picker": "24.3.13",
-    "@vaadin/details": "24.3.13",
-    "@vaadin/dialog": "24.3.13",
-    "@vaadin/email-field": "24.3.13",
-    "@vaadin/field-base": "24.3.13",
-    "@vaadin/field-highlighter": "24.3.13",
-    "@vaadin/form-layout": "24.3.13",
-    "@vaadin/grid": "24.3.13",
-    "@vaadin/horizontal-layout": "24.3.13",
-    "@vaadin/icon": "24.3.13",
-    "@vaadin/icons": "24.3.13",
-    "@vaadin/input-container": "24.3.13",
-    "@vaadin/integer-field": "24.3.13",
-    "@vaadin/item": "24.3.13",
-    "@vaadin/list-box": "24.3.13",
-    "@vaadin/lit-renderer": "24.3.13",
-    "@vaadin/login": "24.3.13",
-    "@vaadin/menu-bar": "24.3.13",
-    "@vaadin/message-input": "24.3.13",
-    "@vaadin/message-list": "24.3.13",
-    "@vaadin/multi-select-combo-box": "24.3.13",
-    "@vaadin/notification": "24.3.13",
-    "@vaadin/number-field": "24.3.13",
-    "@vaadin/overlay": "24.3.13",
-    "@vaadin/password-field": "24.3.13",
-    "@vaadin/polymer-legacy-adapter": "24.3.13",
-    "@vaadin/progress-bar": "24.3.13",
-    "@vaadin/radio-group": "24.3.13",
+    "@vaadin/polymer-legacy-adapter": "24.4.0",
+    "@vaadin/react-components": "24.4.0",
     "@vaadin/router": "1.7.5",
-    "@vaadin/scroller": "24.3.13",
-    "@vaadin/select": "24.3.13",
-    "@vaadin/side-nav": "24.3.13",
-    "@vaadin/split-layout": "24.3.13",
-    "@vaadin/tabs": "24.3.13",
-    "@vaadin/tabsheet": "24.3.13",
-    "@vaadin/text-area": "24.3.13",
-    "@vaadin/text-field": "24.3.13",
-    "@vaadin/time-picker": "24.3.13",
-    "@vaadin/tooltip": "24.3.13",
-    "@vaadin/upload": "24.3.13",
     "@vaadin/vaadin-development-mode-detector": "2.0.7",
-    "@vaadin/vaadin-lumo-styles": "24.3.13",
-    "@vaadin/vaadin-material-styles": "24.3.13",
-    "@vaadin/vaadin-themable-mixin": "24.3.13",
+    "@vaadin/vaadin-lumo-styles": "24.4.0",
+    "@vaadin/vaadin-material-styles": "24.4.0",
+    "@vaadin/vaadin-themable-mixin": "24.4.0",
     "@vaadin/vaadin-usage-statistics": "2.1.2",
-    "@vaadin/vertical-layout": "24.3.13",
-    "@vaadin/virtual-list": "24.3.13",
     "construct-style-sheets-polyfill": "3.1.0",
     "date-fns": "2.29.3",
-    "lit": "3.1.2"
+    "lit": "3.1.4",
+    "react": "18.3.1",
+    "react-dom": "18.3.1",
+    "react-router-dom": "6.23.1"
   },
   "devDependencies": {
-    "@rollup/plugin-replace": "5.0.5",
+    "@babel/preset-react": "7.24.7",
+    "@rollup/plugin-replace": "5.0.7",
     "@rollup/pluginutils": "5.1.0",
-    "@vitejs/plugin-react": "4.2.1",
-    "@vitejs/plugin-react-swc": "3.5.0",
-    "async": "3.2.4",
-    "glob": "10.3.3",
+    "@types/react": "18.3.3",
+    "@types/react-dom": "18.3.0",
+    "@vitejs/plugin-react": "4.3.1",
+    "async": "3.2.5",
+    "glob": "10.4.1",
     "rollup-plugin-brotli": "3.1.0",
     "rollup-plugin-visualizer": "5.12.0",
     "strip-css-comments": "5.0.0",
     "transform-ast": "2.4.4",
-    "typescript": "5.3.3",
-    "vite": "5.1.7",
+    "typescript": "5.4.5",
+    "vite": "5.3.1",
     "vite-plugin-checker": "0.6.4",
-    "workbox-build": "7.0.0",
-    "workbox-core": "7.0.0",
-    "workbox-precaching": "7.0.0"
+    "workbox-build": "7.1.1",
+    "workbox-core": "7.1.0",
+    "workbox-precaching": "7.1.0"
   },
   "vaadin": {
     "dependencies": {
       "@polymer/polymer": "3.5.1",
-      "@vaadin/a11y-base": "24.3.13",
-      "@vaadin/accordion": "24.3.13",
-      "@vaadin/app-layout": "24.3.13",
-      "@vaadin/avatar": "24.3.13",
-      "@vaadin/avatar-group": "24.3.13",
-      "@vaadin/bundles": "24.3.13",
-      "@vaadin/button": "24.3.13",
-      "@vaadin/checkbox": "24.3.13",
-      "@vaadin/checkbox-group": "24.3.13",
-      "@vaadin/combo-box": "24.3.13",
+      "@vaadin/bundles": "24.4.0",
       "@vaadin/common-frontend": "0.0.19",
-      "@vaadin/component-base": "24.3.13",
-      "@vaadin/confirm-dialog": "24.3.13",
-      "@vaadin/context-menu": "24.3.13",
-      "@vaadin/custom-field": "24.3.13",
-      "@vaadin/date-picker": "24.3.13",
-      "@vaadin/date-time-picker": "24.3.13",
-      "@vaadin/details": "24.3.13",
-      "@vaadin/dialog": "24.3.13",
-      "@vaadin/email-field": "24.3.13",
-      "@vaadin/field-base": "24.3.13",
-      "@vaadin/field-highlighter": "24.3.13",
-      "@vaadin/form-layout": "24.3.13",
-      "@vaadin/grid": "24.3.13",
-      "@vaadin/horizontal-layout": "24.3.13",
-      "@vaadin/icon": "24.3.13",
-      "@vaadin/icons": "24.3.13",
-      "@vaadin/input-container": "24.3.13",
-      "@vaadin/integer-field": "24.3.13",
-      "@vaadin/item": "24.3.13",
-      "@vaadin/list-box": "24.3.13",
-      "@vaadin/lit-renderer": "24.3.13",
-      "@vaadin/login": "24.3.13",
-      "@vaadin/menu-bar": "24.3.13",
-      "@vaadin/message-input": "24.3.13",
-      "@vaadin/message-list": "24.3.13",
-      "@vaadin/multi-select-combo-box": "24.3.13",
-      "@vaadin/notification": "24.3.13",
-      "@vaadin/number-field": "24.3.13",
-      "@vaadin/overlay": "24.3.13",
-      "@vaadin/password-field": "24.3.13",
-      "@vaadin/polymer-legacy-adapter": "24.3.13",
-      "@vaadin/progress-bar": "24.3.13",
-      "@vaadin/radio-group": "24.3.13",
+      "@vaadin/polymer-legacy-adapter": "24.4.0",
+      "@vaadin/react-components": "24.4.0",
       "@vaadin/router": "1.7.5",
-      "@vaadin/scroller": "24.3.13",
-      "@vaadin/select": "24.3.13",
-      "@vaadin/side-nav": "24.3.13",
-      "@vaadin/split-layout": "24.3.13",
-      "@vaadin/tabs": "24.3.13",
-      "@vaadin/tabsheet": "24.3.13",
-      "@vaadin/text-area": "24.3.13",
-      "@vaadin/text-field": "24.3.13",
-      "@vaadin/time-picker": "24.3.13",
-      "@vaadin/tooltip": "24.3.13",
-      "@vaadin/upload": "24.3.13",
       "@vaadin/vaadin-development-mode-detector": "2.0.7",
-      "@vaadin/vaadin-lumo-styles": "24.3.13",
-      "@vaadin/vaadin-material-styles": "24.3.13",
-      "@vaadin/vaadin-themable-mixin": "24.3.13",
+      "@vaadin/vaadin-lumo-styles": "24.4.0",
+      "@vaadin/vaadin-material-styles": "24.4.0",
+      "@vaadin/vaadin-themable-mixin": "24.4.0",
       "@vaadin/vaadin-usage-statistics": "2.1.2",
-      "@vaadin/vertical-layout": "24.3.13",
-      "@vaadin/virtual-list": "24.3.13",
       "construct-style-sheets-polyfill": "3.1.0",
       "date-fns": "2.29.3",
-      "lit": "3.1.2"
+      "lit": "3.1.4",
+      "react": "18.3.1",
+      "react-dom": "18.3.1",
+      "react-router-dom": "6.23.1"
     },
     "devDependencies": {
-      "@rollup/plugin-replace": "5.0.5",
+      "@babel/preset-react": "7.24.7",
+      "@rollup/plugin-replace": "5.0.7",
       "@rollup/pluginutils": "5.1.0",
-      "@vitejs/plugin-react": "4.2.1",
-      "@vitejs/plugin-react-swc": "3.5.0",
-      "async": "3.2.4",
-      "glob": "10.3.3",
+      "@types/react": "18.3.3",
+      "@types/react-dom": "18.3.0",
+      "@vitejs/plugin-react": "4.3.1",
+      "async": "3.2.5",
+      "glob": "10.4.1",
       "rollup-plugin-brotli": "3.1.0",
       "rollup-plugin-visualizer": "5.12.0",
       "strip-css-comments": "5.0.0",
       "transform-ast": "2.4.4",
-      "typescript": "5.3.3",
-      "vite": "5.1.7",
+      "typescript": "5.4.5",
+      "vite": "5.3.1",
       "vite-plugin-checker": "0.6.4",
-      "workbox-build": "7.0.0",
-      "workbox-core": "7.0.0",
-      "workbox-precaching": "7.0.0"
+      "workbox-build": "7.1.1",
+      "workbox-core": "7.1.0",
+      "workbox-precaching": "7.1.0"
     },
-    "hash": "1b578191af08a883e68dfca9e08ad525b69d9824e0ec3e82a2689cdcf77b5ffe"
+    "hash": "a138b9347a25dacd61eb23a186fb55a3bff3993609bd58738beb6651e7993e01"
   },
   "overrides": {
     "@vaadin/bundles": "$@vaadin/bundles",
-    "@vaadin/a11y-base": "$@vaadin/a11y-base",
-    "@vaadin/accordion": "$@vaadin/accordion",
-    "@vaadin/app-layout": "$@vaadin/app-layout",
-    "@vaadin/avatar": "$@vaadin/avatar",
-    "@vaadin/avatar-group": "$@vaadin/avatar-group",
-    "@vaadin/button": "$@vaadin/button",
-    "@vaadin/checkbox": "$@vaadin/checkbox",
-    "@vaadin/checkbox-group": "$@vaadin/checkbox-group",
-    "@vaadin/combo-box": "$@vaadin/combo-box",
-    "@vaadin/component-base": "$@vaadin/component-base",
-    "@vaadin/confirm-dialog": "$@vaadin/confirm-dialog",
-    "@vaadin/context-menu": "$@vaadin/context-menu",
-    "@vaadin/custom-field": "$@vaadin/custom-field",
-    "@vaadin/date-picker": "$@vaadin/date-picker",
-    "@vaadin/date-time-picker": "$@vaadin/date-time-picker",
-    "@vaadin/details": "$@vaadin/details",
-    "@vaadin/dialog": "$@vaadin/dialog",
-    "@vaadin/email-field": "$@vaadin/email-field",
-    "@vaadin/field-base": "$@vaadin/field-base",
-    "@vaadin/field-highlighter": "$@vaadin/field-highlighter",
-    "@vaadin/form-layout": "$@vaadin/form-layout",
-    "@vaadin/grid": "$@vaadin/grid",
-    "@vaadin/horizontal-layout": "$@vaadin/horizontal-layout",
-    "@vaadin/icon": "$@vaadin/icon",
-    "@vaadin/icons": "$@vaadin/icons",
-    "@vaadin/input-container": "$@vaadin/input-container",
-    "@vaadin/integer-field": "$@vaadin/integer-field",
-    "@vaadin/item": "$@vaadin/item",
-    "@vaadin/list-box": "$@vaadin/list-box",
-    "@vaadin/lit-renderer": "$@vaadin/lit-renderer",
-    "@vaadin/login": "$@vaadin/login",
-    "@vaadin/menu-bar": "$@vaadin/menu-bar",
-    "@vaadin/message-input": "$@vaadin/message-input",
-    "@vaadin/message-list": "$@vaadin/message-list",
-    "@vaadin/multi-select-combo-box": "$@vaadin/multi-select-combo-box",
-    "@vaadin/notification": "$@vaadin/notification",
-    "@vaadin/number-field": "$@vaadin/number-field",
-    "@vaadin/overlay": "$@vaadin/overlay",
-    "@vaadin/password-field": "$@vaadin/password-field",
     "@vaadin/polymer-legacy-adapter": "$@vaadin/polymer-legacy-adapter",
-    "@vaadin/progress-bar": "$@vaadin/progress-bar",
-    "@vaadin/radio-group": "$@vaadin/radio-group",
-    "@vaadin/scroller": "$@vaadin/scroller",
-    "@vaadin/select": "$@vaadin/select",
-    "@vaadin/side-nav": "$@vaadin/side-nav",
-    "@vaadin/split-layout": "$@vaadin/split-layout",
-    "@vaadin/tabs": "$@vaadin/tabs",
-    "@vaadin/tabsheet": "$@vaadin/tabsheet",
-    "@vaadin/text-area": "$@vaadin/text-area",
-    "@vaadin/text-field": "$@vaadin/text-field",
-    "@vaadin/time-picker": "$@vaadin/time-picker",
-    "@vaadin/tooltip": "$@vaadin/tooltip",
-    "@vaadin/upload": "$@vaadin/upload",
     "@vaadin/vaadin-development-mode-detector": "$@vaadin/vaadin-development-mode-detector",
     "@vaadin/vaadin-lumo-styles": "$@vaadin/vaadin-lumo-styles",
     "@vaadin/vaadin-material-styles": "$@vaadin/vaadin-material-styles",
     "@vaadin/router": "$@vaadin/router",
     "@vaadin/vaadin-usage-statistics": "$@vaadin/vaadin-usage-statistics",
-    "@vaadin/vertical-layout": "$@vaadin/vertical-layout",
-    "@vaadin/virtual-list": "$@vaadin/virtual-list",
     "@vaadin/common-frontend": "$@vaadin/common-frontend",
     "construct-style-sheets-polyfill": "$construct-style-sheets-polyfill",
     "lit": "$lit",
     "@polymer/polymer": "$@polymer/polymer",
     "@vaadin/vaadin-themable-mixin": "$@vaadin/vaadin-themable-mixin",
-    "date-fns": "$date-fns"
+    "date-fns": "$date-fns",
+    "@vaadin/react-components": "$@vaadin/react-components",
+    "react-dom": "$react-dom",
+    "react-router-dom": "$react-router-dom",
+    "react": "$react"
   }
 }

src/main/java/com/ModeratorElection/MainView.java

@@ -14,6 +14,7 @@ import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.component.orderedlayout.VerticalLayout;
 import com.vaadin.flow.router.Route;
 import com.vaadin.flow.router.PageTitle;
+import com.vaadin.flow.spring.annotation.RouteScope;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Configuration;
 
@@ -23,6 +24,7 @@ import java.util.List;
 
 @Route("")
 @PageTitle("Moderatorenwahl")
+@RouteScope
 @Configuration
 public class MainView extends VerticalLayout {
 
@@ -38,8 +40,10 @@ public class MainView extends VerticalLayout {
 
         Button electNow = new Button("Elect!", buttonClickEvent ->  {
             try {
-                Notification moderatorNotification = new Notification()
-                        .show("Nächster Moderator: " + electMember(selectMemberItemsNameslist));
+                ArrayList<String> checkboxSelectedMembers = new ArrayList<>(checkboxGroup.getSelectedItems());
+                new Notification();
+                Notification moderatorNotification = Notification
+                        .show("Nächster Moderator: " + electMember(checkboxSelectedMembers));
                 moderatorNotification.setPosition(Notification.Position.BOTTOM_CENTER);
             } catch(Exception exceptionEvent) {
                 Notification errorNotification = new Notification();
@@ -50,9 +54,7 @@ public class MainView extends VerticalLayout {
                 Button closeButton = new Button(new Icon("lumo", "cross"));
                 closeButton.addThemeVariants(ButtonVariant.LUMO_TERTIARY_INLINE);
                 closeButton.setAriaLabel("Close");
-                closeButton.addClickListener(closeButtonEvent -> {
-                    errorNotification.close();
-                });
+                closeButton.addClickListener(closeButtonEvent -> errorNotification.close());
 
                 HorizontalLayout layout = new HorizontalLayout(text, closeButton);
                 layout.setAlignItems(Alignment.CENTER);

src/main/resources/META-INF/native-image/jni-config.json

@@ -0,0 +1,49 @@
+[
+{
+  "name":"java.awt.GraphicsEnvironment",
+  "methods":[{"name":"isHeadless","parameterTypes":[] }]
+},
+{
+  "name":"java.awt.image.BufferedImage",
+  "fields":[{"name":"colorModel"}, {"name":"imageType"}, {"name":"raster"}],
+  "methods":[{"name":"getRGB","parameterTypes":["int","int","int","int","int[]","int","int"] }, {"name":"setRGB","parameterTypes":["int","int","int","int","int[]","int","int"] }]
+},
+{
+  "name":"java.awt.image.ColorModel",
+  "fields":[{"name":"colorSpace"}, {"name":"colorSpaceType"}, {"name":"isAlphaPremultiplied"}, {"name":"is_sRGB"}, {"name":"nBits"}, {"name":"numComponents"}, {"name":"supportsAlpha"}, {"name":"transparency"}],
+  "methods":[{"name":"getRGBdefault","parameterTypes":[] }]
+},
+{
+  "name":"java.awt.image.Raster",
+  "fields":[{"name":"dataBuffer"}, {"name":"height"}, {"name":"minX"}, {"name":"minY"}, {"name":"numBands"}, {"name":"numDataElements"}, {"name":"sampleModel"}, {"name":"sampleModelTranslateX"}, {"name":"sampleModelTranslateY"}, {"name":"width"}]
+},
+{
+  "name":"java.awt.image.SampleModel",
+  "fields":[{"name":"height"}, {"name":"width"}],
+  "methods":[{"name":"getPixels","parameterTypes":["int","int","int","int","int[]","java.awt.image.DataBuffer"] }, {"name":"setPixels","parameterTypes":["int","int","int","int","int[]","java.awt.image.DataBuffer"] }]
+},
+{
+  "name":"java.awt.image.SinglePixelPackedSampleModel",
+  "fields":[{"name":"bitMasks"}, {"name":"bitOffsets"}, {"name":"bitSizes"}, {"name":"maxBitSize"}]
+},
+{
+  "name":"java.lang.Boolean",
+  "methods":[{"name":"getBoolean","parameterTypes":["java.lang.String"] }]
+},
+{
+  "name":"java.lang.System",
+  "methods":[{"name":"load","parameterTypes":["java.lang.String"] }]
+},
+{
+  "name":"sun.awt.image.ByteComponentRaster",
+  "fields":[{"name":"data"}, {"name":"dataOffsets"}, {"name":"pixelStride"}, {"name":"scanlineStride"}, {"name":"type"}]
+},
+{
+  "name":"sun.java2d.Disposer",
+  "methods":[{"name":"addRecord","parameterTypes":["java.lang.Object","long","long"] }]
+},
+{
+  "name":"sun.management.VMManagementImpl",
+  "fields":[{"name":"compTimeMonitoringSupport"}, {"name":"currentThreadCpuTimeSupport"}, {"name":"objectMonitorUsageSupport"}, {"name":"otherThreadCpuTimeSupport"}, {"name":"remoteDiagnosticCommandsSupport"}, {"name":"synchronizerUsageSupport"}, {"name":"threadAllocatedMemorySupport"}, {"name":"threadContentionMonitoringSupport"}]
+}
+]

src/main/resources/META-INF/native-image/predefined-classes-config.json

@@ -0,0 +1,8 @@
+[
+  {
+    "type":"agent-extracted",
+    "classes":[
+    ]
+  }
+]
+

src/main/resources/META-INF/native-image/proxy-config.json

@@ -0,0 +1,26 @@
+[
+  {
+    "interfaces":["java.lang.reflect.ParameterizedType","org.springframework.core.SerializableTypeWrapper$SerializableTypeProxy","java.io.Serializable"]
+  },
+  {
+    "interfaces":["java.lang.reflect.TypeVariable","org.springframework.core.SerializableTypeWrapper$SerializableTypeProxy","java.io.Serializable"]
+  },
+  {
+    "interfaces":["java.lang.reflect.WildcardType","org.springframework.core.SerializableTypeWrapper$SerializableTypeProxy","java.io.Serializable"]
+  },
+  {
+    "interfaces":["org.atmosphere.cpr.AtmosphereHandler"]
+  },
+  {
+    "interfaces":["org.atmosphere.cpr.Broadcaster"]
+  },
+  {
+    "interfaces":["org.springframework.boot.context.properties.ConfigurationProperties"]
+  },
+  {
+    "interfaces":["org.springframework.web.bind.annotation.PathVariable"]
+  },
+  {
+    "interfaces":["org.springframework.web.bind.annotation.RequestMapping"]
+  }
+]

src/main/resources/META-INF/native-image/serialization-config.json

@@ -0,0 +1,8 @@
+{
+  "types":[
+  ],
+  "lambdaCapturingTypes":[
+  ],
+  "proxies":[
+  ]
+}

src/main/resources/application.properties

@@ -1,4 +1,8 @@
-server.port=${PORT:6333}
+spring.application.name=ModeratorElection
+spring.main.banner-mode=off
+
+server.port=${PORT:8080}
+
 logging.level.org.atmosphere = warn
 spring.mustache.check-template-location = false
 
@@ -6,6 +10,6 @@ spring.mustache.check-template-location = false
 vaadin.launch-browser=true
 # To improve the performance during development.
 # For more information https://vaadin.com/docs/latest/integrations/spring/configuration#special-configuration-parameters
-vaadin.allowed-packages = com.vaadin,org.vaadin,dev.hilla,com.example.application
+vaadin.allowed-packages = com.vaadin,org.vaadin,dev.hilla,com.ModeratorElection.MEApplication
 spring.jpa.defer-datasource-initialization = true
-membernames=${MEMBERNAMES:Micha,Ansgar,Clemens,Mattis,Erik,Mirco}
+membernames=${MEMBERNAMES}

src/test/java/com/ModeratorElection/DemoApplicationTests.java

@@ -1,13 +0,0 @@
-package com.ModeratorElection;
-
-import org.junit.jupiter.api.Test;
-import org.springframework.boot.test.context.SpringBootTest;
-
-@SpringBootTest
-class DemoApplicationTests {
-
-	@Test
-	void contextLoads() {
-	}
-
-}

src/test/java/com/ModeratorElection/MainViewTest.java

@@ -5,12 +5,13 @@ import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;
 
-//@SpringBootTest
+@SpringBootTest(classes = MainView.class)
 public class MainViewTest {
     @Test
     void mainViewConstructor() {
         MainView sut = new MainView("Harry,Sven,Ida");
         CheckboxGroup cgroupTest = (CheckboxGroup) sut.getChildren().filter(child -> child instanceof CheckboxGroup).findAny().orElse(null);
+        assert cgroupTest != null;
         int  cgroupTestSelectedItemsSize = cgroupTest.getSelectedItems().size();
         Assertions.assertEquals(3,cgroupTestSelectedItemsSize);
     }