I used the Plain Java starter app from the Hello World Starters page of downloads.
I updated its Maven POM to the latest versions of dependencies. So Vaadin 23.3.1, Java 19, jetty-maven-plugin 10.0.12, and so on. The POM looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns = "http://maven.apache.org/POM/4.0.0"
xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>project-base</artifactId>
<name>Project base for Vaadin</name>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<maven.compiler.source>19</maven.compiler.source>
<maven.compiler.target>19</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<failOnMissingWebXml>false</failOnMissingWebXml>
<vaadin.version>23.3.1</vaadin.version>
<drivers.downloader.phase>pre-integration-test</drivers.downloader.phase>
</properties>
<repositories>
<!-- The order of definitions matters. Explicitly defining central here to make sure it has the highest priority. -->
<repository>
<id>central</id>
<url>https://repo.maven.apache.org/maven2</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
<repository>
<id>vaadin-prereleases</id>
<url>
https://maven.vaadin.com/vaadin-prereleases/
</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
<!-- Repository used by many Vaadin add-ons -->
<repository>
<id>Vaadin Directory</id>
<url>https://maven.vaadin.com/vaadin-addons</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<!-- The order of definitions matters. Explicitly defining central here to make sure it has the highest priority. -->
<pluginRepository>
<id>central</id>
<url>https://repo.maven.apache.org/maven2</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
<pluginRepository>
<id>vaadin-prereleases</id>
<url>
https://maven.vaadin.com/vaadin-prereleases/
</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.vaadin</groupId>
<artifactId>vaadin-bom</artifactId>
<type>pom</type>
<scope>import</scope>
<version>${vaadin.version}</version>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.vaadin</groupId>
<!-- Replace artifactId with vaadin-core to use only free components -->
<artifactId>vaadin</artifactId>
</dependency>
<!-- Added to provide logging output as Vaadin uses -->
<!-- the unbound SLF4J no-operation (NOP) logger implementation -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.vaadin</groupId>
<artifactId>vaadin-testbench</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/io.github.bonigarcia/webdrivermanager -->
<dependency>
<groupId>io.github.bonigarcia</groupId>
<artifactId>webdrivermanager</artifactId>
<version>5.3.1</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<defaultGoal>jetty:run</defaultGoal>
<plugins>
<!-- Define newer versions of Java compiler and war plugin to
better support the latest JDK versions. -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.10.1</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.2</version>
</plugin>
<!-- Jetty plugin for easy testing without a separate server -->
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>10.0.12</version>
<configuration>
<!--
Configures automatic reload of Jetty server
(with 2 second timeout) when new classes are compiled
(e.g. by IDEs).
Should be disabled when using a proper live reload system,
such as JRebel.
If using IntelliJ IDEA with autocompilation, this
might cause lots of unnecessary compilations in the
background. Consider using "0" and trigger restart manually
by hitting enter.
-->
<scan>2</scan>
<!-- Use war output directory to get the webpack files -->
<!--<webAppConfig>-->
<!-- <allowDuplicateFragmentNames>true</allowDuplicateFragmentNames>-->
<!--</webAppConfig>-->
</configuration>
</plugin>
<!--
Take care of synchronizing java dependencies and imports in
package.json and main.js files.
It also creates webpack.config.js if not exists yet.
-->
<plugin>
<groupId>com.vaadin</groupId>
<artifactId>vaadin-maven-plugin</artifactId>
<version>${vaadin.version}</version>
<executions>
<execution>
<goals>
<goal>prepare-frontend</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<!-- Production mode is activated using -Pproduction -->
<id>production</id>
<build>
<plugins>
<plugin>
<groupId>com.vaadin</groupId>
<artifactId>vaadin-maven-plugin</artifactId>
<version>${vaadin.version}</version>
<executions>
<execution>
<goals>
<goal>build-frontend</goal>
</goals>
<phase>compile</phase>
</execution>
</executions>
<configuration>
<productionMode>true</productionMode>
</configuration>
</plugin>
</plugins>
</build>
</profile>
<profile>
<id>it</id>
<build>
<plugins>
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<configuration>
<!--<scanIntervalSeconds>0</scanIntervalSeconds>-->
<stopPort>8081</stopPort>
<stopWait>5</stopWait>
<stopKey>${project.artifactId}</stopKey>
</configuration>
<executions>
<execution>
<id>start-jetty</id>
<phase>pre-integration-test</phase>
<goals>
<goal>start</goal>
</goals>
</execution>
<execution>
<id>stop-jetty</id>
<phase>post-integration-test</phase>
<goals>
<goal>stop</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- Runs the integration tests (*IT) after the server is started -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>3.0.0-M7</version>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
</execution>
</executions>
<configuration>
<trimStackTrace>false</trimStackTrace>
<enableAssertions>true</enableAssertions>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>
Now I would like to try the pre-release of Vaadin 24.
I understand this new version will have little new in terms of features or fixes. Instead, this new version is aimed at making the transition from being based on Java EE 8 to being based on Jakarta EE 10. As discussed in this Vaadin company blog page, this leap involves (a) the dropping of some deprecated features, and (b) the switching of package names from javax.* to jakarta.*. These changes are part of the transition from Oracle donating Java EE technologies to the Eclipse Foundation to become Jakarta EE.
