This Java switch statement doesn’t work on with my IntelliJ settings. Can someone help me point to the right portions of IntelliJ where I can solve this problem?

Intelij displays error message:

error: illegal start of expression return switch (setType) {

when running this code:

private static SimpleAbstractSet<String> makeSet(String setType){
    return switch (setType) {
        case "HashSet" -> new SimpleHashSet<>();
        case "TreeSet" -> new SimpleTreeSet<>();
        ...
        default -> throw new IllegalArgumentException();
    };
}

The code I’m using is from the MOOC “Functional Programming with Java and Threads from the vanderBiltUniveristy. It is on https://github.com/douglascraigschmidt/ and does work with them. Therefore I’m looking in my environment and IDE setup to see if I can find the error.

Linux CentOS

• java version 21.0.4
• gradle version 8.4
• JAVA_HOME=/usr/lib/jvm/jdk-21.0.4-oracle-x64
• GRADLE_HOME=/opt/gradle/gradle-8.4
• PATH=/opt/gradle/gradle-8.4/bin:/usr/lib/jvm-21.0.4-oracle-x64/bin:…..

InteliJ Project Structure

• SDK: 21 Oracle OpenJDK 21.0.4
• Language level 21- Record patterns,…..
• JDK home path /usr/lib/jvm/jdk-21.0.4-oracle-x64

InteliJ Project Settings

• Gradle user home /opt/gradle/gradle-8.4
• Gradle JVM JAVA_HOME

gradle-wrapper.properties

• …
• distributionUrl=https://services.gradle.org/distributions/gradle-8.4-bin.zip
• …

build gradle

group 'livelessons'
version '1.0-SNAPSHOT'

apply plugin: 'java'

repositories {
  mavenCentral()
}
dependencies {
  implementation 'org.jsoup:jsoup:1.14.3'
}

Solution

InteliJ Setting | Build Tools | Gradle

every example of the MOOC is a separate gradle project. For reasons I do not know some of the projects are set by inteliJ to use Gradle JVM 11. These need to be set to JAVA_HOME Oracle OpenJDK 21.0.4