How to add output of task to srcDir of SourceSet

Question

How can I add the output of a task to a SourceSet. My goal is that the task will implicitly be executed before compileGenJava-task.

sourceSets  {
  gen {
    java {
      srcDir "${buildDir}/generated-sources/markup2pojo" // equals output directory of generateSources
    }
  }
[...]

Answer 1

see https://docs.gradle.org/current/userguide/java_plugin.html#sec:changing_java_project_layout

if you have task that generates code before compile ; you can add the generated folder path ex: build/gensrc

sourceSets {
    main {
        java {
            srcDirs = ['src/java', 'build/gensrc']
        }
        resources {
            srcDirs = ['src/resources']
        }
    }
}

Answer 2

I had this exact question and posted to the Gradle forum before finding this answer. Turns out there is a better way than just adding the generated path. See this link for the whole discussion: https://discuss.gradle.org/t/implicit-dependencies-warning-with-sourcesjar/45741?u=bobpaige

Longer Answer: Adding the path works, but at build time (I'm using Gradle 7.4.2) I saw warnings about dependencies when I added the option to generate a sources jar. The respondent on the other forum pointed out the preferred method is to set the srcDir with the task. For example:

java {
  withSourceJar()
}

task myCodeGenerationTask () {
  inputs.dir("...")
  outputs.dir("...")
  // details left as an exercise for the reader
}

sourceSets {
  main {
    java {
      srcDir(myCodeGenerationTask)
    }
  }
}

This "links" the output of the task to the srcDir property used by the source-lib generator.

Note: It is important to put the sourceSets declaration after the task declaration or it won't work.