Is Maven mandatory for Clojure on the JVM?

Question

I'm a bit surprised at the sheer number of articles / blogs / questions / answers about Clojure mentioning Maven.

In about ten years working as a Java dev, working on both desktop apps and webapps, I've never ever used Maven once (typically --and that's a personal opinion but I know some people do think the same-- the projects I've seen using Maven where including the "kitchen sink" whereas the ones built with a more "controlled" build process where way "cleaner" and producing smaller jars, faster build time, etc.).

Is Maven a requirement when you want to build a Clojure app?

Is Maven mandatory when you want to use Leiningen? For example, can I add external jars as dependencies to a leiningen project "manually", without needing Maven?

I think my question boils down to this: can you, in the Clojure/JVM world get away without ever using Maven, just like you can build, test, package and ship both Java desktop, webapps and Android apps without ever needing Maven?

Answer 1

Short answer: No. Clojure's just a jar and you can use it as "raw" as you like, just like any other Java library.

Longer answer: Maven's not a requirement, but the tooling around Clojure, especially Leiningen, is highly Maven-aligned so your life will be easier if you just submit to Maven's will. But, with a little work, it's not that hard to get along without Maven. At work, I use a mix of Leiningen and our existing Ant/Ivy-based build infrastructure. I use Ant to resolve dependencies (from our curated internal repo) and then use a hack of Leiningen's :resource-paths to get it to pick up the non-Maven jars. At some point I'll make a true plugin to do this stuff, but it's been working fine for me so far.

Also, if you're an Eclipse person and use CounterClockwise, you can treat your project like any other Java project in Eclipse, managing the classpath manually. It just happens that you've got some Clojure code in there as well.

Of course, the drawback in either approach is that if you want to grab something that's available from either Maven central or Clojars, you'll either have to set up some kind of mirror for your infrastructure, or manually pull down the transitive dependencies and add them to your project.