Note
 A Human wrote this article. Other than proofreading and sentence-level style suggestions, no AI was utilized. This is one of the last surviving members of its kind.

1. Introduction

You want to use Maven, but you feel uneasy with the XML format of the pom file. What to do?

2. Introduction 2

The introduction says it all, but here we go a bit more detailed.

When developing a Java project, you can choose different build tools. The most commonly used tools are Maven and Gradle. Lingering from the past, you may sometimes see remnants of old Ant projects. There are Sbt, Bazel, Buck, Pant, and Mill. These are niche tools. You can also try Bach if you like to experiment. If you’re familiar with Maven and Gradle, you should be' good to go.

Maven was created to be a declarative build tool, as opposed to the that-time prevalent Ant’s commanding nature. Grade followed Maven many years later when developers started to feel the limitations of this declarativeness. Developers like freedom. They/we want to tell the developer tool what to do. After all, we have programmed that way for the last 70 years in various imperative programming languages. You may find some Prolog programmers in some dusty corners behind some long-locked-up doors if you peek. Do not. Close those doors back and let the departed rest.

Enterprises (a.k.a. the leaders of developers, representing the enterprise and its objectives) do not appreciate developer autonomy. Freedom results in individual solutions. An individual solution is always more expensive to maintain than a uniform one. This is also true for the build systems and Gradle.

If you ever download an open-source project from GitHub using Gradle, what is the first command you execute?

    gradle tasks

…​then you can see in the output what tasks there are, and then, only after you understand what tasks you can perform, can you start the build. What does the same look like in the case of Maven?

    mvn clean install

and it builds the project for you.

As a side note, it is a shame that you use clean install when a simple verify is enough. This is a kind of muscle memory coming from the everyday development when there is an old, messed-up partial build in the target directory, and you learned from IDE integration that it is better if you always have the up-to-date version in the local repo.

Nevertheless, it is standard, well-known, like the wq! keystroke to exit vi.

Enterprises (a.k.a. managers) often prefer Maven. A new team member, or a new team, does not need to spend time learning the build structure. Maven projects have a standard structure.

If you need a specific step in the build process, you may face an issue. You need to use a Maven plugin or create a new one. From the management point of view, difficulty is also an advantage. Making it challenging to create project-specific items in the build process will ensure developers do it only when absolutely necessary.

The price for all these advantages is that you have to use XML to configure the project. After all, XML is so enterprise, isn’t it? Or can you avoid using XML in the POM file?

Multiple solutions try to do that, so developers need to exist.

In the article, we will examine existing solutions, their pros and cons, and then propose a new one that retains the advantages and mitigates most of the disadvantages.

3. How not to XML in POM?

If you want to replace the XML format with something else in the pom files, you can have two approaches:

  • preprocess some project definition and produce the XML as the output before the compilation starts, or

  • use a Maven extension that reads the project structure from some proprietary format.

The first approach is not professional. It is not integrated into the Maven ecosystem, and it is proprietary. The other one is Polyglot Maven.

Polyglot Maven is a Maven extension. Maven loads a Maven extension before reading the pom file, and the extension can hook itself up with Maven, registering for the task of reading the project object model. If you want to run a Maven extension, you should create an .mvn directory in your project with an extensions.xml:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  <extensions>
    <extension>
        <groupId></groupId>
        <artifactId></artifactId>
        <version></version>
    </extension>
</extensions>

Maven will automatically load the extension provided by the Maven coordinates and run it.

Polyglot Maven can read the project object model in different formats, including

  • atom,

  • clojure,

  • groovy,

  • java,

  • kotlin,

  • ruby,

  • scala,

  • yaml.

The project is at

https://github.com/takari/polyglot-maven

4. Summary

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