5 Maven Plugins to Turbocharge Your AEM Development

A confession, oftentimes I use this blog as a bookmark for helpful tools and information that's scattered across the internet. This is most definitely one of those type of posts. Hopefully you find it helpful too!

I'd note this post doesn't cover "basic" Maven commands such as installing an AEM project, but instead focuses on less-common but invaluable commands.

Getting "Stuff" Into AEM

AEM makes it pretty easy to get content / code in and out of the system with JCR FileVault Packages and OSGi Bundles. With these Maven plugins you can automate it!

#1 Install / Download Content Packages with the content-package-maven-plugin

JCR FileVault Packages are the easiest way to get content in and out of AEM, allowing for developers and administrators to easily package, download and install content between AEM instances.

Adobe provides the Content Package Maven Plugin which besides being critical to code deployments can be used for ad-hoc package installation.

# Install a package artifact from Maven
mvn content-package:install -Dvault.artifact=com.adobe.aem.guides:aem-guides-wknd.all:1.1.0:zip

# Installing a local file
mvn content-package:install -Dvault.file=./package.zip

You can use the content package plugin to install external content packages, but it also can be used as a one liner for building and installing your project with:

# Build and install an AEM project
mvn clean install content-package:install

You can even use the content package plugin to back up content in an instance automatically.

# First we build the package
mvn content-package:build -Dvault.path=/etc/packages/com.adobe.aem-assets/test-content.zip -DfailOnError=true

# Next, download the package
mvn content-package:download -Dvault.path=/etc/packages/com.adobe.aem-assets/test-content.zip -Dvault.outputFile=test-content.zip

# Do whatever you need to do...

# Reinstall the package
mvn content-package:install -Dvault.file=test-content.zip

#2 Install Bundles with the sling-maven-plugin

OSGi bundles contain the Java code for AEM projects. While you generally won't need to download a bundle from an AEM instance, with the sling-maven-plugin can deploy a bundle with a single command!

# Install the bundle in the current project directory
mvn sling:install

Or if you need to build the project and want to also install the bundle in one step:

# Build and install a bundle project
mvn clean install sling:install

If this command tries to deploy the bundle to port 8080, ensure your POM.xml sets the slingUrl to http://localhost:4502/system/console and sets the deploymentMethod to WebConsole.

Finally, you may want to install a bundle directly from a file or the Maven Repository:

# Install from Maven
mvn sling:install-file -Dsling.artifact=org.apache.sling:org.apache.sling.serviceuser.webconsole:1.0.2 -Dsling.url=http://localhost:4502/system/console -Dsling.deploy.method=WebConsole

# Install from a file
mvn sling:install-file -D sling.file=./mybundle.jar -Dsling.url=http://localhost:4502/system/console -Dsling.deploy.method=WebConsole

Managing AEM Projects

Beyond the typical commands like mvn clean install or mvn test or mvn verify -Dtest=[testname], Apache Maven plugins can make it much easier to maintain AEM projects.

#3 Getting an Artifact with the Maven Dependencies Plugin

It can be a pain to find, then download and copy dependencies you need to run locally from Maven outside the context of a Maven project. Thankfully, there's a plugin or that!

Let's say you needed oak-run v1.40.0:

# Download Oak-Run into the current directory
mvn dependency:copy -Dartifact=org.apache.jackrabbit:oak-run:1.40.0 -DoutputDirectory=.

# Download the dependency and strip the version
mvn dependency:copy -Dartifact=org.apache.jackrabbit:oak-run:1.40.0  -Dmdep.stripVersion=true -DoutputDirectory=.

#4 Getting a Property from a POM with the Help Maven Plugin

Let's say you had two projects with properties that you wanted to keep in sync. You could automate updating the variables, but how do you get the property value from the POM?

With the Help Maven Plugin, you can evaluate a property and write the value to standard out:

# Get the property java.version as a bash variable
JAVA_VERSION=$(mvn help:evaluate -Dexpression=java.version -q -DforceStdout)

#5 Update Dependencies with the Maven Versions Plugin

AEM is composed of many dependencies, along with any dependencies specific to your project. Keeping these dependencies up to date, along with the various plugins for the project requires constant maintenance.

# Displays the available dependencies
mvn versions:display-dependency-updates

# Displays the available plugin versions
mvn versions:display-plugin-updates

Hope these Maven commands help you be a more effective AEM developer. Did I miss your favorite command? Leave a comment!