TheNEXUS

Maven by Example
- 2.5. Maven Installation Details

2.5. Maven Installation Details

Maven’s download measures in at a few megabyte only. It has attained such a slim download size because the core of Maven has been designed to retrieve plugins and dependencies from a remote repository on-demand. When you start using Maven, it will start to download plugins to a local repository described in Section 2.5.1, “User-Specific Configuration and Repository”. In case you are curious, let’s take a quick look at what is in Maven’s installation directory.

/usr/local/maven $ ls -p1
LICENSE.txt
NOTICE
README.txt
bin/
boot/
conf/
lib/

LICENSE.txt contains the software license for Apache Maven. The lib/ directory contains a the JAR files that contains the core of Maven.

Note

Unless you are working in a shared Unix environment, you should avoid customizing the settings.xml in conf. Altering the global settings.xml file in the Maven installation itself is usually unnecessary and it tends to complicate the upgrade procedure for Maven as you’ll have to remember to copy the customized settings.xml from the old Maven installation to the new installation. If you need to customize settings.xml, you should be editing your own settings.xml in ~/.m2/settings.xml.

2.5.1. User-Specific Configuration and Repository

Once you start using Maven extensively, you’ll notice that Maven has created some local user-specific configuration files and a local repository in your home directory. In ~/.m2 there will be:

~/.m2/settings.xml: A file containing user-specific configuration for authentication, repositories, and other information to customize the behavior of Maven.
~/.m2/repository/: This directory contains your local Maven repository. When you download a dependency from a remote Maven repository, Maven stores a copy of the dependency in your local repository.

Note

In Unix (and OS X), your home directory will be referred to using a tilde (i.e. ~/bin refers to /home/tobrien/bin). In Windows, we will also be using ~ to refer to your home directory. In Windows XP, your home directory is C:\Documents and Settings\tobrien, and in Windows Vista, your home directory is C:\Users\tobrien. From this point forward, you should translate paths such as ~/m2 to your operating system’s equivalent.

2.5.2. Upgrading a Maven Installation

If you’ve installed Maven on a Mac OS X or Unix machine according to the details in Section 2.3.1, “Installing Maven on Linux, BSD and Mac OS X”, it should be easy to upgrade to newer versions of Maven when they become available. Simply install the newer version of Maven (/usr/local/maven-3.future) next to the existing version of Maven (/usr/local/maven-3.0.3). Then switch the symbolic link /usr/local/maven from /usr/local/maven-3.0.3 to /usr/local/maven-3.future. Since you’ve already set your PATH variable to point to /usr/local/maven, you won’t need to change any environment variables.

If you have installed Maven on a Windows machine, simply unpack Maven to C:\Program Files\maven-3.future and update your PATH variable.

Note

If you have any customizations to the global settings.xml in conf, you will need to copy this settings.xml to the conf directory of the new Maven installation.

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