Archive a Directory as a JAR

Synopsis

This chapter shows how any folder can be quickly archived as a versioned maven artifact (of type JAR).

Purpose

• Package up scrips and resources (e.g. datasets) as maven artifacts that can be used in downstream build pipelines. For example, in the Build anything with Docker chapter, a JAR bundle with python resources is extracted for building the docker image.

Approach

The following pom.xml is self-contained. The jar bundle can be built with

mvn package

It adds the current folder and its sub folders recursively to the jar file in the target folder. Adjust the folder property to a meaningful folder of your project such as src.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.aksw.maven4data.examples</groupId>
  <artifactId>my-archived-directory</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <!-- JAR files are ZIP files, so we are actually just creating a ZIP file here -->
  <packaging>jar</packaging>

  <properties>
    <!-- Adjust the path to your needs -->
    <directory-to-archive>.</directory-to-archive>

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <!-- Include the specified folder as a resource. Its contents will be added to the root of the JAR bundle. -->
  <build>
    <resources>
      <resource>
        <directory>${directory-to-archive}</directory>
      </resource>
    </resources>
  </build>
</project>

Another Example

The following is a more realistic example of a project structure:

|- README.md
|- src
|  |- requirements.txt
|  |- run.sh
|  +- LICENSE.txt
|
|- LICENSE.txt # symlink to src/LICENSE.txt
|- pom.xml
|
| # The build output created with "mvn package":
+- target
   +- archive-folder-1.0.0-SNAPSHOT.jar

By setting the folder property to src in the above pom.xml, the content of the src folder up at the root of the versioned JAR file.