How to set Java language level to 8 in JetBrains Fleet?

Question

I can't find the config to set Java language level.

Answer 1

You might find the answer here How to change project language level for all project in Intellij

Change the sourceCompality to 1.8, if it didn't work, also change the Project structure JDK.

Answer 2

If you are using Maven, in pom.xml file use:

<properties>
    <maven.compiler.target>11</maven.compiler.target>
    <maven.compiler.source>11</maven.compiler.source>
</properties>

If you are using Gradle, in build.gradle file use:

java {
    sourceCompatibility = JavaVersion.VERSION_11
    targetCompatibility = JavaVersion.VERSION_11
}