LCSim module artifacts such as jar files are deployed to a remote repository where they are publically available for download, either manually or via a dependency in a POM file. These repositories have directory and file structures that allow Maven to find these dependencies when building dependent projects.
When building, Maven will cache artifacts from remote repositories into a local repository so that it does not need to fetch them from the internet every time. By default, the location of the local repository is ~/.m2/settings.xml on Linux and OSX or the user home area on Windows.
This location can be configured differently via the settings file at ~/.m2/settings.xml:
<settings> ... <localRepository>/path/to/local/repo/</localRepository> ... </settings>
Or it may be set from the command line for an individual build, as follows:
mvn -Dmaven.repo.local=/path/to/my/repo
In fact, periodically removing and then rebuilding the local repository is a good idea, as it can make clear any possible dependency problems that might be otherwise hidden.
The following information can be put into the repositories section of your project's POM file so that LCSim artifacts will be downloaded when found in the dependencies:
<repository>
<id>lcsim-repo-public</id>
<name>LCSIM Public Maven Repository</name>
<url>http://srs.slac.stanford.edu/nexus/content/groups/lcsim-maven2-public/</url>
</repository>Both releases and snapshots are available through that URL, so this should be the only configuration that is required.
The Sonatype Nexus application is used to manage the repository.
To search for jars, go to the SLAC SRS Nexus Application and enter "lcsim" in the "Keyword Search" box, which will show the artifacts that are available.
Maven has the concept of the snapshot version, which is a rolling release that is subject to change over time. There can be many remote snapshot versions, because they are deployed automatically by the continuous integration system.
Artifacts of this type have long names including a unique identifer, such as:
lcsim-distribution-3.0-20131214.221640-10-bin.jar
It is easy to spot snapshot dependencies in POM files as these have "SNAPSHOT" in the name, for instance:
<dependency>
<groupId>org.lcsim</groupId>
<artifactId>lcsim-distribution</artifactId>
<version>3.0-SNAPSHOT</version>
<dependency>When referenced in this way, the latest version of the snapshot will be pulled automatically from the remote repository, or a copy will be used from the local repository if it has a more recent timestamp.
Snapshot versions must be updated when releases are made, so after the "3.0" release is made, the snapshot version would be changed to "3.1-SNAPSHOT" in anticipation of the "3.1" release.
Release versions point to artifacts that usually do not change once deployed to the remote repository.
These artifacts have short names including the release such as:
lcsim-distribution-3.0-bin.jar
A dependency on that release would look like this in a POM file:
<dependency>
<groupId>org.lcsim</groupId>
<artifactId>lcsim-distribution</artifactId>
<version>3.0</version>
<dependency>Depending on release versions has the benefit that a project will not be affected by changes in the HEAD copy of the dependency which are usually deployed automatically to remote repositories.