painless publishing of android libraries

Libraries are only good when it’s easy to share them. Android has done this wrong for a very long time.

Node.js has npm and a new library can be published in a couple of minutes, usage is as simple as adding library name to package.json.

Go has no package manager at all and publishing a library is as simple as “git push” and using is as simple as “import github.com/user/library”.

Android… Before Gradle it was a real disaster. Gradle finally made it possible to add libraries with just one line of code. But publishing your new library was still a problem.

maven central

Obviously, in Java world libraries are managed with Maven. When I published my first android library I’ve chosen Maven Central and described the steps I’ve taken.

It was a cumbersome process which required writing some code, creating an account on their website and waiting for a few days to make my registration complete.

That’s why when I heard about jCenter I decided to migrate.

jcenter

Actually, I decided to migrate when I’ve read that Android Studio migrates to jcenter.

So I’ve made a Bintray account, added some gradle plugins to my libraries, wrote another few lines of gradle configuration and published my library. The process is well documented but look at the amount of code to be written!

And as a result you still have to link your library with jCenter and wait until they confirm your request.

jitpack

Finally, I’ve heard about JitPack.io.

Finally, no registration needed. You only need to have a repository on github or bitbucket.

Finally, no need to wait for any kind of confirmation before you can publish your new library.

Finally, publishing is as simple as git push and using is as simple as writing your library name in build.gradle.

step-by-step

First, create a new project on github. Assuming it’s an android library it can follow the structure of this repo: https://github.com/jitpack/android-example/

Basically, all you need to change is to add android maven plugin to your library/build.gradle:

buildscript {
	dependencies {
		...
		classpath 'com.github.dcendents:android-maven-gradle-plugin:1.3'
	}
}

apply plugin: 'com.android.library'
apply plugin: 'com.github.dcendents.android-maven'

You might also want to add this to generate javadocs and sources JAR:

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

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

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

artifacts {
    archives sourcesJar
    archives javadocJar
}

Next, assign a release tag and push your code:

git tag 1.0
git push
git push --tags

Publishing is done. You may now use your library in other projects:

repositories {
	maven { url = 'https://jitpack.io' }
}
dependencies {
	// for https://github.com/user/library with tag 1.0:
	compile 'com.github.user:library:1.0'
}

And yes, that is it.

If you don’t have an assigned tag yet - you may use com.github.user:library:-SNAPSHOT and will always get the “tip” of the master branch.

links

Official documentation for JitPack publishing of Android libraries: here: https://jitpack.io/docs/ANDROID/

Official example of an Android library: https://github.com/jitpack/android-example/

Issue tracker: https://github.com/jitpack/jitpack.io/issues

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Dec 11, 2015