Creating an Adobe Experience Manager 6.4 Project using Adobe Maven Archetype 13

Introduction
You can create an Adobe Experience Manager 6.4 project by using Adobe Maven Archetype 13. This development article walks you through creating an Experience Manager 6.4 project by using Archetype 13 and explains the default AEM files and services. Using an Archetype 13 project, you are given a set of files to start with.

Pages
English and French pages with filler text

Templates
For homepage and content pages
Homepages are only allowed on the top level, and content pages below
Built with HTL templates and simple server-side JavaScript logic

Example Components
helloworld - example of custom HTL component with SlingModels for the logic
core components - use of Core Components like text and image, and title

Java examples
Models: Models for the more complex business logic of components
Servlets: Rendering the output of specific requests
Filters: Applied to the requests before dispatching to the servlet or script
Schedulers: Cron-job like tasks

The following illustration represents a default Experience Manager page that is created by the Archetype 13 project.

A default page created by Maven Archetype 13

Note:
The Maven Archetype 13 project uses Declarative Services annotations. For information, see OFFICIAL OSGI DECLARATIVE SERVICES ANNOTATIONS IN AEM.

Setup Maven in your development environment
You can use Maven to build an OSGi bundle that contains a Sling Servlet. Maven manages required JAR files that a Java project needs in its classpath. Instead of searching the Internet trying to find and download third-party JAR files to include in your project’s classpath, Maven manages these dependencies for you.

You can download Maven 3 from the following URL:
http://maven.apache.org/download.html

After you download and extract Maven, create an environment variable named M3_HOME. Assign the Maven to install location to this environment variable. For example:

C:\Programs\Apache\apache-maven-3.0.4

Set up a system environment variable to reference Maven. To test whether you properly setup Maven, enter the following Maven command into a command prompt:

%M3_HOME%\bin\mvn -version

This command provides Maven and Java to install details and resembles the following message:

Default locale: en_US, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"

Note: It is recommended that you use Maven 3.0.3 or greater. For more information about setting up Maven and the Home variable, see Maven in 5 Minutes.

Next, copy the Maven configuration file named settings.xml from [install location]\apache-maven-3.0.4\conf\ to your user profile. For example, C:\Users\scottm\.m2\.

You have to configure your settings.xml file to use Adobe’s public repository. For information, see Adobe Public Maven Repository at http://repo.adobe.com/.

The following XML code represents a settings.xml file that you can use.

<?xml version="1.0" encoding="UTF-8"?>




<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">







<pluginGroups>

</pluginGroups>


<proxies>

</proxies>


<servers>



</servers>


<mirrors>

</mirrors>


<profiles>




<profile>

<id>adobe-public</id>

<activation>

<activeByDefault>true</activeByDefault>

</activation>

<repositories>

<repository>

<id>adobe</id>

<name>Nexus Proxy Repository</name>

<url>http://repo.adobe.com/nexus/content/groups/public/</url>

<layout>default</layout>

</repository>

</repositories>

<pluginRepositories>

<pluginRepository>

<id>adobe</id>

<name>Nexus Proxy Repository</name>

<url>http://repo.adobe.com/nexus/content/groups/public/</url>

<layout>default</layout>

</pluginRepository>

</pluginRepositories>

</profile>

</profiles>


</settings>

Note:
The Adobe repository URL is now made secured. Change http://repo.adobe.com/nexus/content/groups/public/ to https://repo.adobe.com/nexus/content/groups/public/.

Create an AEM Maven 13 archetype project
You can create an Experience Manager archetype project by using the Maven archetype plugin. In this example, assume that the working directory is C:\AdobeCQ.

Files generated by Maven 13 Archetype
To create an Experience Manager archetype project, perform these steps:
1. Open the command prompt and go to your working directory (for example, C:\AdobeCQ).

2. Run the following Maven command:
mvn org.apache.maven.plugins:maven-archetype-plugin:2.4:generate -DarchetypeGroupId=com.adobe.granite.archetypes -DarchetypeArtifactId=aem-project-archetype -DarchetypeVersion=13 -DarchetypeCatalog=https://repo.adobe.com/nexus/content/groups/public/
3. When prompted, specify the following information:
groupId - AEMMaven13
artifactId - AEMMaven13
version - 1.0-SNAPSHOT
package - com.aem.community
appsFolderName - AEMMaven13
artifactName - AEMMaven13
componentGroupName - AEMMaven13
confFolderName - AEMMaven13
contentFolderName - AEMMaven13
cssId - AEMMaven13
packageGroup - AEMMaven13
siteName - AEMMaven13

4. When prompted, specify Y.

5. Once done, you will see a message like:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:42 min
[INFO] Finished at: 2016-04-25T14:34:19-04:00
[INFO] Final Memory: 16M/463M
[INFO] ------------------------------------------------------------------------
6. Change the working directory to AEMMaven13 using cd AEMMaven13, and then enter the following command.

mvn eclipse:eclipse

After you run this command, you can import the project into Eclipse as discussed in the next section.

Add Java files to the Maven project using Eclipse
To make it easier to work with the Maven generated project, import it into the Eclipse development environment, as shown in the following illustration.

Eclipse Import Project Dialog

Note:
Do not worry about the errors reported in Eclipse. It does not read the POM file where the APIs are resolved. You build the bundle with Maven. Eclipse is used to edit the Java files and the POM file.

After you import the project into Eclipse, notice each module is a separate Eclipse project:
core - where Java files that are used in OSGi services and sling servlets are located
launcher - where additional Java files are located
tests - Java files for tests like JUNIT tests
apps - content under /apps
content - content under /content

When you want to create an OSGi service, you work under the core. Likewise, if you want to create an HTL component, you can work under apps.

By default, the Archetype 13 project creates a number of Java files that you can use as a starting point in your project (these Java files are located under core).

The following illustration shows the packages.

Default Java source files

LOGGINGFILTER CLASS
The LoggingFilter class performs a simple servlet filter operation that logs incoming requests. The following code represents this class.

package com.aem.community.core.filters;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.engine.EngineConstants;
import org.osgi.framework.Constants;
import org.osgi.service.component.annotations.Component;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* Simple servlet filter component that logs incoming requests.
*/
@Component(service = Filter.class,
property = {
Constants.SERVICE_DESCRIPTION + "=Demo to filter incoming requests",
EngineConstants.SLING_FILTER_SCOPE + "=" + EngineConstants.FILTER_SCOPE_REQUEST,
Constants.SERVICE_RANKING + ":Integer=-700"

})
public class LoggingFilter implements Filter {

private final Logger logger = LoggerFactory.getLogger(getClass());

@Override
public void doFilter(final ServletRequest request, final ServletResponse response,
final FilterChain filterChain) throws IOException, ServletException {

final SlingHttpServletRequest slingRequest = (SlingHttpServletRequest) request;
logger.debug("request for {}, with selector {}", slingRequest
.getRequestPathInfo().getResourcePath(), slingRequest
.getRequestPathInfo().getSelectorString());

filterChain.doFilter(request, response);
}

@Override
public void init(FilterConfig filterConfig) {
}

@Override
public void destroy() {
}
}

SIMPLERESOURCELISTENER
The SimpleResourceListener class is a service to demonstrate how changes in the resource tree can be listened to. It registers an event handler service and uses these annotations.
@Component – defines the class as a component

The following Java code represents the SimpleResourceListener class.

package com.aem.community.core.listeners;

import org.apache.sling.api.SlingConstants;
import org.osgi.framework.Constants;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* A service to demonstrate how changes in the resource tree
* can be listened for. It registers an event handler service.
* The component is activated immediately after the bundle is
* started through the immediate flag.
* Please note, that apart from EventHandler services,
* the immediate flag should not be set on a service.
*/
@Component(service = EventHandler.class,
immediate = true,
property = {
Constants.SERVICE_DESCRIPTION + "=Demo to listen on changes in the resource tree",
EventConstants.EVENT_TOPIC + "=org/apache/sling/api/resource/Resource/*"
})
public class SimpleResourceListener implements EventHandler {

private final Logger logger = LoggerFactory.getLogger(getClass());

public void handleEvent(final Event event) {
logger.debug("Resource event: {} at: {}", event.getTopic(), event.getProperty(SlingConstants.PROPERTY_PATH));
}
}

HELLOWORLDMODEL CLASS
The HelloWorldModel is a sample class that uses Sling Models. This class uses Sling Model annotations such as @Model. For information, see Sling Models.

The following class represents the HelloWorldModel class.

package com.aem.community.core.models;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;

import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Default;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.settings.SlingSettingsService;

@Model(adaptables=Resource.class)
public class HelloWorldModel {

@Inject
private SlingSettingsService settings;

@Inject @Named("sling:resourceType") @Default(values="No resourceType")
protected String resourceType;

private String message;

@PostConstruct
protected void init() {
message = "\tHello World!\n";
message += "\tThis is instance: " + settings.getSlingId() + "\n";
message += "\tResource type is: " + resourceType + "\n";
}

public String getMessage() {
return message;
}
}

SIMPLESCHEDULEDTASK
This class is an AEM scheduler for cron-job like tasks that get executed regularly. It also demonstrates how property values can be set. Users can set the property values in /system/console/configMg. For more information about Sling Scheduler functionality, see Scheduler Service.

The following Java code represents this class.
package com.aem.community.core.schedulers;

import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.Designate;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* A simple demo for cron-job like tasks that get executed regularly.
* It also demonstrates how property values can be set. Users can
* set the property values in /system/console/configMgr
*/
@Designate(ocd=SimpleScheduledTask.Config.class)
@Component(service=Runnable.class)
public class SimpleScheduledTask implements Runnable {

@ObjectClassDefinition(name="A scheduled task",
description = "Simple demo for cron-job like task with properties")
public static @interface Config {

@AttributeDefinition(name = "Cron-job expression")
String scheduler_expression() default "*/30 * * * * ?";

@AttributeDefinition(name = "Concurrent task",
description = "Whether or not to schedule this task concurrently")
boolean scheduler_concurrent() default false;

@AttributeDefinition(name = "A parameter",
description = "Can be configured in /system/console/configMgr")
String myParameter() default "";
}

private final Logger logger = LoggerFactory.getLogger(getClass());

private String myParameter;

@Override
public void run() {
logger.debug("SimpleScheduledTask is now running, myParameter='{}'", myParameter);
}

@Activate
protected void activate(final Config config) {
myParameter = config.myParameter();
}
}

Note:
This class reads AEM Configuration values. For more information, see Reading OSGi Configuration Values for Adobe Experience Manager 6.3.

SIMPLESERVLET
The SimpleServlet class represents a simple AEM servlet created using Apache Sling APIs. This servlet using resource type binding to invoke the servlet. In this example, it binds to AEMMaven13/structure/page. The following Java code represents the SimpleServlet class.

package com.aem.community.core.servlets;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.servlets.HttpConstants;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.apache.sling.api.resource.ValueMap;
import org.osgi.framework.Constants;
import org.osgi.service.component.annotations.Component;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import java.io.IOException;

/**
* Servlet that writes some sample content into the response. It is mounted for
* all resources of a specific Sling resource type. The
* {@link SlingSafeMethodsServlet} shall be used for HTTP methods that are
* idempotent. For write operations use the {@link SlingAllMethodsServlet}.
*/
@Component(service=Servlet.class,
property={
Constants.SERVICE_DESCRIPTION + "=Simple Demo Servlet",
"sling.servlet.methods=" + HttpConstants.METHOD_GET,
"sling.servlet.resourceTypes="+ "AEMMaven13/components/structure/page",
"sling.servlet.extensions=" + "txt"
})
public class SimpleServlet extends SlingSafeMethodsServlet {

private static final long serialVersionUid = 1L;

@Override
protected void doGet(final SlingHttpServletRequest req,
final SlingHttpServletResponse resp) throws ServletException, IOException {
final Resource resource = req.getResource();
resp.setContentType("text/plain");
resp.getWriter().write("Title = " + resource.adaptTo(ValueMap.class).get("jcr:title"));
}
}

Note:
For more information about creating an AEM servlet that binds to resources, see Binding Adobe Experience Manager Servlets to ResourceTypes.

Modify the Maven POM file
Add the following POM dependency to the POM file located at C:\AdobeCQ\AEMMaven13.

<dependency>
<groupId>com.adobe.aem</groupId>
<artifactId>uber-jar</artifactId>
<version>6.4.0</version>
<classifier>apis</classifier>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-atinject_1.0_spec</artifactId>
<version>1.0</version>
<scope>provided</scope>
</dependency>

When you add new Java classes under core, you need to modify a POM file to successfully build the OSGi bundle. You modify the POM file located at C:\AdobeCQ\AEMMaven13\core.

The following code represents this POM file.

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>AEMMaven13</groupId>
<artifactId>AEMMaven13</artifactId>
<version>1.0-SNAPSHOT</version>
<relativePath>../pom.xml</relativePath>
</parent>
<artifactId>AEMMaven13.core</artifactId>
<packaging>bundle</packaging>
<name>AEMMaven13 - Core</name>
<description>Core bundle for AEMMaven13</description>
<build>
<plugins>
<plugin>
<groupId>org.apache.sling</groupId>
<artifactId>maven-sling-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.felix</groupId>
<artifactId>maven-bundle-plugin</artifactId>
<extensions>true</extensions>
<configuration>
<instructions>

<Import-Package>javax.inject;version=0.0.0,*</Import-Package>
<Sling-Model-Packages>
com.aem.community.core
</Sling-Model-Packages>
</instructions>
</configuration>
</plugin>
</plugins>
</build>

<dependencies>

<dependency>
<groupId>com.adobe.aem</groupId>
<artifactId>uber-jar</artifactId>
<classifier>apis</classifier>
</dependency>

<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-atinject_1.0_spec</artifactId>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>osgi.core</artifactId>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>osgi.cmpn</artifactId>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>osgi.annotation</artifactId>
</dependency>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
</dependency>
<dependency>
<groupId>javax.jcr</groupId>
<artifactId>jcr</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
</dependency>
<dependency>
<groupId>com.adobe.aem</groupId>
<artifactId>uber-jar</artifactId>
<classifier>apis</classifier>
</dependency>
<dependency>
<groupId>org.apache.sling</groupId>
<artifactId>org.apache.sling.models.api</artifactId>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
</dependency>
<dependency>
<groupId>junit-addons</groupId>
<artifactId>junit-addons</artifactId>
</dependency>
</dependencies>
</project>
Build the OSGi bundle using Maven
To build the OSGi bundle by using Maven, perform these steps:
Open the command prompt and go to the C:\AdobeCQ\AEMMaven13.
Run the following maven command: mvn -PautoInstallPackage install.
The OSGi component can be found in the following folder: C:\AdobeCQ\AAEMMaven13\core\target. The file name of the OSGi component is AEMMaven13.core-1.0-SNAPSHOT.jar.

The command -PautoInstallPackage automatically deploys the OSGi bundle to AEM.

View the Active OSGi bundle
After you deploy the OSGi bundle by using the Maven command, you can see it in an active state in the Adobe Apache Felix Web Console.

The OSGi bundle in an Active State

View your OSGi bundle by performing these steps:
Log in to Adobe Apache Felix Web Console at http://server:port/system/console/bundles (default admin user = admin with password= admin).
Click the Bundles tab, sort the bundle list by Id, and note the Id of the last bundle.

Understand the UI Apps content
The Maven Archetype 13 project creates default files under /apps, as shown in this illustration.

Default files under /apps/AEMMaven13

The following list describes these files:
A - default components that you can use in your project. You can also modify these components to meet your business requirements.
B - default files that are used in the same form in the AEMMaven13/en.html page
C - files that create page content, including footers, top navigation, and so on. For example, you can find footer content in this file: /apps/AEMMaven13/components/structure/page/customfooterlibs.html
D - configuration information for the OSGi service.
E - default i18n files
F - defines two templates: page content and page home.

AEMMaven13 default components
The following default components are created under components/content:
breadcrumb - a component that overlays the BreadCrumb Core component
helloworld - a basic component that displays text
image - a basic image component
list - a component that overlays the List Core component
text - a basic text component
title - a basic title component
languagenavigation - component for language navigation

navigation - basic component for navigating an item
search - basic search component
sharing - basic share component

HELLOWORLD COMPONENT
The helloworld component is a basic HTL component that displays text. Notice the following code.

<p data-sly-test="${properties.text}">Text property: ${properties.text}</p>

<pre data-sly-use.hello="com.aem.community.core.models.HelloWorldModel">
HelloWorldModel says:
${hello.message}
</pre>

The first thing to notice about this code is:<pre data-sly-use.hello="com.adobecq.community.core.models.HelloWorldModel">

In this example, data-sly-use.hello references the Java class named HelloWorldModel. (This class is explained earlier in this article). The HelloWorldModel uses Sling Models. This line of code:

${hello.message}

returns the value of the getMessage method in the HelloWorldModel class. This value is displayed by the helloworld component.

Note:
You can see the output of the helloworld component in the illustration shown at the start of this development article.

IMAGE COMPONENT
The image component displays an image within an AEM web page. An author can drag and drop an image from the side rail into the image dialog, as shown in this illustration.

The default image component

The image is displayed on the page, as shown here.

The image displayed in the page

The image component inherits from the Core image component. This is made possible by setting the component's sling:resourceSuperType property to core/wcm/components/image/v1/image. This is how component inheritance works with AEM. For more information about component inheritance, see AEM Components - the Basics.

TEXT COMPONENT
The text component lets an author enter text into an AEM web page. Like the image component, this component inherits from the text Core component by setting the sling:resourceSuperType property to core/wcm/components/text/v1/text.

TITLE COMPONENT
The title component lets an author enter a title into an AEM web page. This component inherits from the title Core component by setting the sling:resourceSuperType property to core/wcm/components/title/v1/title.

AEMMAVEN13 PAGE COMPONENT
Under /apps/AEMMaven13/components/structure, there is a Page component, as shown here.

Default files for the Page component

The page component is an HTL component that defines a footer and header.

DEFAULT CLIENTLIBS FOR AEMMAVEN13
The Archetype 13 project creates a default clientlib location for your AEM project. This clientlibs folder is located at the following location:
/apps/AEMMaven13/clientlibs

If you need to add additional CSS or JS files to your project, you can add them there. When you package up your project, include this folder as well.

Running the default web page
You can view the default web page by using the following URL:
http://localhost:4502/editor.html/content/AEMMaven13/en.html

Notice that this page displays the HelloWorld component. This following video shows this use case.

AEM Tutorials for Beginners

April 18, 2020
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