Introduction

Want to create a binary distribution from a Maven project that includes supporting scripts, configuration files, and all runtime dependencies? You need to use the assembly plugin to create a distribution for your project.

This plugin generates "assemblies". It is the equivalent of the Maven 1 distribution plug-in. This plugin provides the capability to create binary and source distributions. These distributions (assemblies) are defined using an assembly descriptor. You can write your own description to create a custom assembly, or you can reuse one of the three pre-defined assemblies.

Currently it can create distribution formats such as: zip, tar.bz, tar.gz2, and jar.

To use the assembly plugin in Maven 2, you simply need to:

  • configure the assembly in pom.xml,
  • write an assembly descriptor, and
  • run "mvn assembly:assembly"

For a more detailed, step-by-step introduction to the assembly plugin, read this HOW-TO.

To write your own custom assembly, you will need to refer to the assembly.html}Assembly Descriptor Format reference.

What is an Assembly?

An "assembly" is a group of files, directories, and dependencies that is assembled into an archive format and distributed. For example, assume that a Maven project defines a single JAR artifact that contains both a console application and a Swing application. Such a project could define two "assemblies" that bundle the application with a different set of supporting scripts and dependency sets. One assembly would be the assembly for the console application, and the other assembly could be a Swing application bundled with a slightly different set of dependencies.

This assembly plugin provides a descriptor format which allows you to define an arbitrary assembly of files and directories from a project. For example, if your Maven 2 project contains the directory "src/main/bin", you can instruct the assembly plugin to copy the contents of this directory to the "bin" directory of an assembly and to change the permissions of the files in the "bin" directory to UNIX mode 755. The parameters for configuring this behavior are supplied to the assembly plugin by way of the assembly descriptor.

Goal Overview

An overview of the assembly plugin's goals can be found here. To create a binary distribution for a project, use the "assembly:assembly" goal. To extract all project dependencies on certain working directory, use the "assembly:unpack".