How can JavaDocs be configured to be generated in a specified project root directory?

Question

I want to generate my JavaDocs into a given directory in my project root, I know that the destinationDir property exists, but how do I use it also given that my build.gradle exists within a directory inside of my project root. I provided a small diagram below:

/projectRoot
  /lib
    /build/docs/javaDocs <--- JavaDocs here by default
    build.gradle
  /docs <---- Need JavaDocs here 

Taking a look at the documentation for JavaDocs in gradle, here. I knew that the destinationDir property existed so I attempted to set it like the provided example. This didn't have the intended affect and instead generated nothing, or is it going something outside of my project directory?

tasks.withType(Javadoc).configureEach {
    exclude ('com/nest/egg/**')
    options.addStringOption("charset", "utf-8")
    options.addStringOption("docencoding", "utf-8")
    options.addStringOption("encoding", "utf-8")
    destinationDir = reporting.file("docs") // Also tried "/docs", "docs/"
}

Answer 1

You need to pass a Java File object to destinationDir specifying your desired location¹. So you can write:

destinationDir = layout.projectDirectory.dir("..").dir("docs").asFile

Here you are using Gradle's ProjectLayout object. Each dir() call gives you a Gradle Directory so you must finally call asFile to finally get the Java File object that you need.

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¹I am not sure what object you are using when you call reporting.file("docs") but the ProjectLayout object gives you all you need.