9.0.0

Following JFrog announcement about sunsetting JCenter, maoni and all the default callback implementations are now available on Maven Central. See https://search.maven.org/artifact/org.rm3l/maoni.
So importing maoni should be straightforward. Add this to your build.gradle file:

  repositories {
      //...
      mavenCentral()
  }

  dependencies {
    // ...
    implementation 'org.rm3l:maoni:9.0.0@aar'
  }