How to Develop AEM Projects using IntelliJ IDEA

To get started with AEM development on IntelliJ, the following steps are required.

Each of them is explained in more detail in the remainder of this How-To.

• Install IntelliJ
• Set up your AEM project based on Maven
• Prepare JSP support for IntelliJ in the Maven POM
• Import the Maven Project into IntelliJ

Download IntelliJ IDEA from the Downloads page at JetBrains.

Then, follow the installation instructions on that page.

Next, set up your project using Maven as described in How-To Build AEM Projects using Apache Maven.

To start working with AEM projects in IntelliJ IDEA, the basic setup in Getting Started in 5 Minutes is sufficient.

IntelliJ IDEA can also provide support in working with JSP, e.g.

• auto-completion of tag libraries
• awareness of objects defined by <cq:defineObjects /> and <sling:defineObjects />

For that to work, follow the instructions on How-To Work with JSPs in How-To Build AEM Projects using Apache Maven.

The following steps are necessary for debugging JSPs with IntelliJ IDEA

• Set up a Web Facet in the Project
• Install the JSR45 support plugin 
• Configure a Debug Profile
• Configure AEM for Debug Mode

IntelliJ IDEA needs to understand where to find the JSPs for debugging. As IDEA cannot interpret the content-package-maven-plugin settings, this needs to be configured manually.

1. Go to File -> Project Structure
2. Select the "content" module
3. Click "+" above the list of modules and select "Web"
4. As the Web Resource Directory, select the content/src/main/content/jcr_root subdirectory of your project as shown in the screen shot below.

1. Go to the "Plugins" pane in the IntelliJ IDEA settings
2. Navigate to the "JSR45 Integration" Plugin and select the check box next to it
3. Click "Apply"
4. Restart IntelliJ IDEA when requested to

1. Go to "Run" -> "Edit Configurations"
2. Hit the "+" and select "JSR45 Remote"
3. In the configuration dialog, select "Configure" next to "Application Server" and configure a Generic server
4. Set the start page to an appropriate URL if you want to open a browser when you start debugging
5. Remove all "Before launch" tasks if you use vlt autosync, or configure appropriate Maven tasks if you don't
6. On the "Startup/Connection" pane, adjust the port if required
7. Copy the command line arguments that IntelliJ IDEA proposes

The last step required is to start AEM with the JVM options proposed by IntelliJ IDEA.

You can do this by starting the AEM jar file directly and adding these options, for example with the following command line:

java -Xdebug -Xrunjdwp:transport=dt_socket,address=58242,suspend=n,server=y -Xmx1024m -XX:MaxPermSize=256M -jar cq-quickstart-5.6.1.jar

You can also add these options to your start script in crx-quickstart/bin/start as shown below.

You are now all set up for debugging your JSPs in AEM.

1. Select "Run" -> "Debug" -> Your Debug Profile
2. Set breakpoints in your component code
3. Access a page in your browser

Code in bundles can be debugged using a standard generic remote debug connection. You can follow the Jetbrain documentation on remote debugging.