Useful Maven Commands for offline dependencies

Show the actual pom settings

mvn help:effective-pom

Dependency plugin to manage dependencies

mvn dependency:tree
mvn dependency:analyze

Download dependencies (with sources and javadocs) to local repo

mvn dependency:go-offline dependency:sources -Dmaven.repo.local=/tmp/repo
mvn dependency:go-offline dependency:sources -Dclassifier=javadoc -Dmaven.repo.local=/tmp/repo

Create a local repo with all dependencies

mvn clean install -Dmaven.repo.local=/tmp/repo

or add the following to settings.xml default profile:
<properties>
   <downloadSources>true</downloadSources>
   <downloadJavadocs>true</downloadJavadocs>
</properties>

mvn dependency:go-offline dependency:sources -Dmaven.repo.local=/tmp/repo
mvn dependency:go-offline dependency:sources -Dclassifier=javadoc -Dmaven.repo.local=/tmp/repo

Offline build

mvn -o install