Error: Java: invalid target release: 11 - IntelliJ IDEA

java

intellij-idea

java-compiler

jdk-11

byAlex Kataev·Dec 25, 2024

To fix the "invalid target release: 11" error by setting up JDK 11 in IntelliJ IDEA, follow these steps:

For Maven, set the Java version in the pom.xml:

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

In Gradle, define it in the build.gradle file:

sourceCompatibility = '11' // Teach Gradle to 'talk' Java 11
targetCompatibility = '11' // Tell it to also 'walk' Java 11

Lastly, perform a project rebuild.

Setup checks and IDE compatibility

Sometimes, the nitty-gritty of configuration settings can make development a tad frustrating. With these steps, I hope to make it a tad more fun:

IDE version: Verify your IntelliJ IDEA version. If you're working with JDK 11, the IDE version should be at least IntelliJ IDEA 2018.x.
Environment Variables: Check that JAVA_HOME and Path variables lead to the verified JDK 11 installation.
Compiler Settings: IDE's secret language involves compilers, ensure your IntelliJ IDEA understands JDK 11 by default in the Java Compiler settings.

Persistent errors are annoying, like a coffee stain on your favorite white shirt. Here are some fresh approaches:

Project Language Level: Make sure the Project language level is the same as your JDK version (11 in this case).
Bytecode Confirmation: Verify the Project bytecode version and Module bytecode versions match up to JDK 11.
Project JDK Path: IntelliJ IDEA sometimes gets lost, guide it to JDK 11 by manually updating the JDK path in Project Structure.
Persistent issues: .idea/ directory causing headache? Consider deleting and reopening the project; it ejects potential corruption in IntelliJ’s config files.

Modern build tools like Maven and Gradle can further augment your JDK management:

Maven: In pom.xml, confidently declare your Java version to be 11.
Gradle: In build.gradle, use JavaVersion.VERSION_11. It's like Gradle's secret handshake confirming a Java 11 project.

You've got everything right, yet your project throws tantrums. Your check-list for those stubborn issues:

IntelliJ IDEA’s Path Awareness: If IntelliJ IDEA returns a "not a valid home" error, revisit Project Structure and re-add JDK 11.
Project Dependency Check: Any dependencies playing hooky with a different JDK version?
Outdated IDE Version: Old isn't always gold. Update your IntelliJ IDEA to a version that supports JDK 11.

Does Bytecode seem like a cryptic conversation between your code and the JVM? Well, indeed it is!

Project Files: Corruption in .idea/ directory or project files (.iml) can happen and if suspected, delete and let IntelliJ recreate those.
JDK Path: Ensure that the installation path of JDK 11 is accurately referenced in IntelliJ IDEA's settings.
Language Level: Don't mismatch the language level with your JDK version. Make sure both are 11 in this case.

Command-line tools can save the day when IDE is playing up:

Use javac with -source and -target parameters. It's like manually driving your code compilation.
Maven command-line: mvn clean install ensures your build uses Java version specified in pom.xml (not just for wizards!).
Gradle command-line: ./gradlew build hand picks settings from build.gradle (it's like a backstage pass!).