Gradle error: "Could not find property '...' on root project '...'

Question

I try do build my Java project with Gradle and I'm getting the following:

Starting Build
Settings evaluated using settings file 'C:\Users\MyName\Java8\MyJavaProject\settings.gradle'.
Projects loaded. Root project using build file 'C:\Users\MyName\Java8\MyJavaProject\build.gradle'.
Included projects: [root project 'MyJavaProject']
Evaluating root project 'MyJavaProject' using build file 'C:\Users\MyName\Java8\MyJavaProject\build.gradle'.

FAILURE: Build failed with an exception.

* Where:
Build file 'C:\Users\MyName\Java8\MyJavaProject\build.gradle' line: 25

* What went wrong:
A problem occurred evaluating root project 'MyJavaProject'.
> Could not find property 'myJavaPackage' on root project 'MyJavaProject'.

Line 25 of build.gradle: mainClassName = myJavaPackage.runner.MainRunner

In settings.gradle I have: rootProject.name = 'MyJavaProject'

Project directory structure:

MyJavaProject-> main -> java -> myJavaPackage -> runner -> MainRunner

I'm using Gradle 11.1

Since the stack trace is huge I did not post the entire one.

Close to the bottom it shows:

Caused by: groovy.lang.MissingPropertyException: Could not find property 'myJavaPackage' on root project 'MyJavaProject'.

I searched for this type of error but the answers were mostly about upgrading Gradle from an old version to a newer one.

What did I do wrong?

Answer 1

Correct is (notice the quotes):

mainClassName = "myJavaPackage.runner.MainRunner"