Of Gradle, Groovy, and How I’ve Come to Love Build Automation

I finally got my project at work to build using Gradle. Grade is a build tool, something like make or ant except that it is implemented as a Domain Specific Language (DSL) built on top of Groovy. Groovy is a remarkable language in its own right. It is a dynamic language that compiles to Java byte code so it runs on the Java Virtual Machine (JVM). It can freely call code written in Java and Java code can call code written in it. This gives Groovy an enormous head start in terms of the variety of libraries that it can take advantage of right out of the box.

What is so great about Groovy, anyway? Well, it is a lot less verbose than Java for one thing. You rarely need to use semicolons in Groovy. Usually, it knows where the end of a statement is without you having to tell it explicitly with a semicolon. Another thing Groovy is good at is figuring out the types of variables without explicitly being told. This makes it easy to define a variable using the def keyword and letting Groovy figure out the type of the variable by what you assign to it. Groovy is touted as a scripting language and it does serve in that capacity very well but it can also be used to write very succinct and flexible object oriented code, like Java. Another place where Groovy saves typing is with imports. All of the more commonly used library packages are included by default.

Groovy also adds a new syntax for cleanly entering Map constants. This makes creating keyword/value data structures much easier. These are very useful for collecting information such as configuration parameters. There are lots of other neat features that Groovy brings to the table but to get back to Gradle, it is an application, written in Groovy specifically for managing the build process.

Gradle makes the build process a lot more expressive. It is more concise while at the same time being more flexible. It is easily extended both in an ad-hoc fashion by writing code specific to the build at hand as well as in a more general fashion by supporting plug-ins that can be shared among many different projects.

Using Gradle to automate my build process has turned a tedious job into one that is as exciting for me as writing the rest of the code in my application is. If you are developing in Java or Groovy or any other language for that matter, I suggest that you give Gradle a look.