How to add Gradle to existing JavaFX Project (IntelliJ)

Question

From this post (Best way to add Gradle support to IntelliJ Project) I can see that what I need to do is "Add build.gradle in your project's root directory."

I was hoping someone could please explain how I do that in intelliJ? (been searching and reading - still baffled).

I understand a root directory the folder which is the parent for all the project sources, but in standard JavaFX project in intelliJ what is it/how do I find it/assign it, and then how do I add build.gradle?

TheKodeToad · Accepted Answer · 2021-11-26T11:34:31.340

1

Note: these steps assume that you are using the latest JDK version (17).

In the project browser, right click on the project name and create a file named build.gradle:

Write a build script. Here is a template for JavaFX applications:

plugins {
  id "application"                              // Use Application plugin
  id "org.openjfx.javafxplugin" version "0.0.9" // Use JavaFX plugin
}

mainClassName = "my.package.Application" // Set this to your main class

repositories {
    mavenCentral()
}

javafx {
    version = "16"                  // JavaFX Version
    modules = [ "javafx.controls" ] // JavaFX modules. Add them to this array.
}

Once you have finished, import the project:

This may take a while depending on your internet speed.

You may have to adjust runtime configurations to use Gradle, but that shouldn't be necessary.

You may encounter the following error:

BUG! exception in phase 'semantic analysis' in source unit '_BuildScript_' Unsupported class file major version 61

If that is the case, install Gradle CLI (if you haven't already), and open a command prompt/terminal in the project folder.

Run the following command (works on Windows/Mac/Linux):

gradle wrapper --gradle-version=7.3 --distribution-type=bin

Once you have done that, reload the Gradle project.

I could not resist another GIF:

You may also need to rearrange the source folders:

I apologise for the cat photo, but it was just a placeholder image. I definitely didn't specifically choose it.

edited Nov 26 '21 at 11:34

answered Nov 25 '21 at 15:52

TheKodeToad

301
2
10

thanks a lot for putting that answer together. I followed the steps and changed the class name in your buildscript to my Main, but I get the following error: "Could not open init generic class cache for initialization script...BUG! exception in phase 'semantic analysis' in source unit '_BuildScript_' Unsupported class file major version 60"... I'm way out of my depth here – sillyPin Nov 25 '21 at 16:42
That's the problem I had. I just assumed that it was an issue with my machine. I fixed it a few weeks ago, but forgot how. I'll just try and find what I did with my other project to get it working. – TheKodeToad Nov 26 '21 at 09:27
I have added a fix to the answer. – TheKodeToad Nov 26 '21 at 09:45
That got it! Absolute legend, thanks. Must be a gradle version/JDK compatibility issue. Despite not changing the JDK version I actually had to update IntelliJ before it worked as well, not sure why. But it worked. It has brought up an error running Main now, but I assume that's due to the project structure needing to be what gradle expects- I can have a look at that. Cheers for your help, much appreciated :) – sillyPin Nov 26 '21 at 10:50
Ah never mind re what I said about Main I missed your last gif on source folders. Thanks a lot! I enjoyed the cat...no worries – sillyPin Nov 26 '21 at 11:10

How to add Gradle to existing JavaFX Project (IntelliJ)

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