How to copy only OS specific dependency jars by Maven? - maven

Question

I'm currently working on a project that uses (among others) nd4j, deeplearning4j dependencies. These dependencies include versions for different OS, like "nd4j-native-1.0.0-beta6-android-arm.jar" or "nd4j-native-1.0.0-beta6-linux-armhf.jar" etc.
As the project will only run on linux-x64, I'm wondering whether there's a way to tell Maven to not copy the JARs that are not needed. I hope to reduce the required disk space needed by unnecessary libs.
The pom.xml currently looks like this to be able to produce a deployable output:
<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>MyGroup</groupId>
<artifactId>MyApp</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>org.apache.clerezza.ext</groupId>
<artifactId>org.json.simple</artifactId>
<version>0.4</version>
</dependency>
<dependency>
<groupId>com.kohlschutter.junixsocket</groupId>
<artifactId>junixsocket-core</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>com.kohlschutter.junixsocket</groupId>
<artifactId>junixsocket-server</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>org.nd4j</groupId>
<artifactId>nd4j-native-platform</artifactId>
<version>1.0.0-beta6</version>
</dependency>
<dependency>
<groupId>org.deeplearning4j</groupId>
<artifactId>deeplearning4j-core</artifactId>
<version>1.0.0-beta6</version>
</dependency>
<dependency>
<groupId>org.deeplearning4j</groupId>
<artifactId>deeplearning4j-parallel-wrapper</artifactId>
<version>1.0.0-beta6</version>
</dependency>
</dependencies>
<packaging>jar</packaging>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/libs</outputDirectory>
<useRepositoryLayout>true</useRepositoryLayout>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathLayoutType>repository</classpathLayoutType>
<classpathPrefix>libs/</classpathPrefix>
<mainClass>MyMainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
</project>

Answer 1

Generally if you want to bundle platform specific binaries for dl4j or anything based on javacpp, you can do the following:
https://github.com/bytedeco/javacpp-presets/wiki/Reducing-the-Number-of-Dependencies
Concretely, you would just specify -Djavacpp.platform=linux-x86_64 for all javacpp dependencies.

Answer 2

You can set <exclusions> on dependencies:
https://maven.apache.org/guides/introduction/introduction-to-optional-and-excludes-dependencies.html
An example would be:
<dependency>
<groupId>com.something</groupId>
<artifactId>some-jar</artifactId>
<version>1.0.0</version>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>de.dumm</groupId>
<artifactId>nicht-benutzen</artifactId>
</exclusion>
</exclusions>
</dependency>