Issue to build project with gradle 8.5 and java 21

Question

I use java 21 gradle 8.5 intellij 2023.2.2

In a spring boot 3.2 project in the build.gradle i have

plugins {
    id 'java'
    id 'org.springframework.boot' version '3.2.0'
    id 'io.spring.dependency-management' version '1.1.4'
}

group = 'com.acme.intranet-backend'
version '0.0.34-SNAPSHOT'

java {
    sourceCompatibility = '21'
}

when i build project, i

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':intranet:compileJava'. at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:148) at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:282) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:146) at Caused by: java.lang.IllegalArgumentException: error: invalid source release: 21

Answer 1

By default, IDEA uses Gradle wrapper which in turn uses its own configuration of Java runtime.

If you go into

Settings -> Build, Execution, Deployment -> Gradle

you can change Gradle default JVM into Java 21 ("Gradle JVM" property).

If you do not have JDK 21 installed, select "Download SDK" and pick one of Java 21 versions (personally I prefer Eclipse Temurin SDK).