How to generate Android *.jar Library with javadoc included?

Question

I am working an a library project for Android with Android Studio. The project contains a javadoc, but when I build a jar file with Gradle and use the library in another project, I cannot access the documentation.

Generating the html javadoc is possible, but not quite convenient. I want to have the documentation inside the jar file (which will be shipped to other users) to see it directly, eg using the Android Studio mouse-hover feature on the code.

Is there a way to include the javadoc into the generated jar file?

Answer 1

It is not possible to grab sources or javadoc from a compiled jar.

However build systems like gradle and maven support additional jars: If you upload your artifact to eg Maven central, just put an additional jar with a -sources or -javadoc suffix with the respective content in parallel to the main jar.

To generate these jars, use the following gradle tasks

task sourcesJar(type: Jar) {
    from android.sourceSets.main.java.srcDirs
    classifier = 'sources'
}

task javadoc(type: Javadoc) {
    source = android.sourceSets.main.java.srcDirs
    classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
    failOnError false
}

task javadocJar(type: Jar, dependsOn: javadoc) {
    classifier = 'javadoc'
    from javadoc.destinationDir
}