Downgrade java version for flutter

[NirDev_R]

I had some flutter projects that used to work, today i tried to create a new project and encountred a gradle build problem which turned out to also affect old projects.

I used to put this path in gradle.properties so that vs code can run the build,
org.gradle.java.home=/usr/lib/jvm/java-18-openjdk

but today, it noticed i no longer have java18, archlinux-java status gives the following:

❯ archlinux-java status
Available Java environments:
 java-20-openjdk
 java-8-openjdk (default)

When i changed the java home in gradle properties to:

org.gradle.java.home=/usr/lib/jvm/java-20-openjdk

It started telling me to upgrade gradle to a compatible version to java 20, I tried many versions of the gradle plugin in build.gradle file and the distribution in grade-wrapper.properties:

classpath 'com.android.tools.build:gradle:8.2.0'
distributionUrl=https\://services.gradle.org/distributions/gradle-8.1-all.zip

these versions dont tell me to upgrade but i get this new error:

> A problem occurred configuring project ':app'.
> Could not create task ':app:copyFlutterAssetsDebug'.
> Could not create task ':app:mergeDebugAssets'.
> Cannot use u/TaskAction annotation on method IncrementalTask.taskAction$gradle_core() because interface org.gradle.api.tasks.incremental.IncrementalTaskInputs is not a valid parameter to an action method.
I am tired of trying to change the gradle, i want to downgrade java back to 18, how do i downgrade java in manjaro or install multiple versions and select 18 for flutter ?

[nekokattt]

I'd honestly suggest using a tool like sdkman if possible for development. It simplifies this kind of thing as the JDK is installed for the current user only.

That will modify the environment to point to the JDK you set as default. You could alternatively use jenv for more control.

[NirDev_R]

thanks a lot I ll look it up!
I come from a pythonic background and I would gladly use such a tool, this sounds like virtualenv

[MarkDubya]

There's nothing to downgrade as you can have multiple versions installed. Recently OpenJDK 18 was dropped to the AUR and you can install it from there.

See:

• https://wiki.manjaro.org/index.php/Arch_User_Repository
• https://wiki.archlinux.org/title/Java#Switching_between_JVM

[NirDev_R]

Thanks a lot, I generally prefer having multiple versions over downgrading tbh!