While upgrading to the Java 17 version using the OpenJDK built by Microsoft, I also ran into problems because the Java source files were now encoded using the default Windows encoding, instead of UTF-8.

To fix the problem, set the file.encoding property to UTF-8.

The easiest way to do it is to set the MAVEN_OPTS environment variable:

MAVEN_OPTS=-Dfile.encoding=UTF-8

Another option is to pass it to the Maven Surefire plugin:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>${maven-surefire-plugin.version}</version>
    <configuration>
        <argLine>-Dfile.encoding=UTF-8</argLine>
    </configuration>
</plugin>

And, if you want to start a Java program, then pass the -Dfile.encoding=UTF8 property.