Chapter 16. Repository Manager
Repository managers serve two purposes: they act as highly configurable proxies between your organization and the public Maven repositories, and they also provide an organization with a deployment destination for your own generated artifacts.
Proxying a Maven repository brings a number of benefits. Proxying speeds up builds throughout your organization by installing a local cache for all artifacts from the central Maven repository. If a developer in your organization needs to download version 2.5 of the Spring Framework and you are using Nexus, the dependencies (and the dependencies’ dependencies) need to be downloaded from the remote repository only once. With a high-speed connection to the Internet, this might seem like a minor concern, but if you are constantly asking your developers to download hundreds of megabytes of third-party dependencies, the real cost savings are going to be the time it takes Maven to check for new versions of dependencies and to download them. Serving Maven dependencies from a local repository can save you hundreds of requests over HTTP, and in very large multiproject builds, this can shave minutes from a build.
If your project is relying on a number of snapshot dependencies, Maven will need to check for updated version of these snapshots. Depending on the configuration of your remote repositories, Maven will check for snapshot updates periodically, or it might check for snapshot updates on every build. When Maven ...