Class files are not being created

I'm trying to get a very basic app compiled using Gradle and it's not working.
The build\classes directory is not being created.
I'm able to compile the Java files using javac and it runs as expected, so I don't think it's a Java issue.
I'm running this on a Windows 10 Pro system with only Java 9 installed.

I'm following this guide: https://spring.io/guides/gs/gradle/#scratch
I get to this point of the guide:

Guide wrote:The first time you run the wrapper for a specified version of Gradle, it downloads and caches the Gradle binaries for that version.
The Gradle Wrapper files are designed to be committed to source control so that anyone can build the project without having to first install and configure a specific version of Gradle.

At this stage, you will have built your code. You can see the results here:

The problem is that the class files are not created.
Here is my spring/build.gradle

Java file spring\src\main\hello\Greeter.java contents:

Java file spring\src\main\hello\HelloWorld.java contents:

Can you please tell me what I've done wrong and how I can fix it?

Fixed, I had the incorrect directory structure. Gradle needs to have the files in project_folder/src/main/java/package_name and I had them in project_folder/src/main/package_name.

Thanks for coming back with your findings and solution.

And how is Gradle, you like it?

I just found on their website some upcoming training sessions (free), might want to note down some of those if free around that time.
https://gradle.org/training/

I do like Gradle, but maybe that's because that's all that I've use. I have not tried Maven and I don't plan to. Gradle was adopted by Android Studio, which is where I was introduced to it.

I do wonder why there is Ant, Maven, Gradle and others if they all do the same thing.

Thanks for the training link.

Pete Letkeman wrote:I do wonder why there is Ant, Maven, Gradle and others if they all do the same thing.

Probably similar as to why there are so many programming languages, with their own pros and cons.

To my knowledge, Gradle is by far most modern now and flexible among other build tools. Gradle uses Groovy implementation, making build script more concise. Ant and Maven are XML based.
On daily basis I'm using Maven and I believe it is still most widely used build tool as of now, with Ant I have very little experience.