Servlets in CQ5 | How to write/register servlets in CQ5

      Initially the Servlet API specification states the following with respect to the life cycle of Servlets:



       The servlet container calls the init method exactly once after instantiating the servlet.

This works perfectly in a regular servlet container which both instantiates and initializes the servlets. With Sling the tasks of instantiation and initialization are split:

• The provider of the Servlet service takes care of creating the servlet instance
• The Sling Servlet Resolver picks up the Servlet services and initializes and destroys them as needed

     So Sling has not way of making sure a Servlet is only initialized and destroyed once in the life time of the Servlet object instance.

The provider of the Servlet service on the other can cope with this situation by making sure to drop the servlet instance once it is destroyed. The mechanism helping the provider here is the OSGi Service Factory.

Registering a Servlet : 

     Servlets can be registered as OSGi services. The following service reference properties are defined for Servlets defined as OSGi services of type javax.servlet.Servlet:

• sling.servlet.paths
• sling.servlet.resourceTypes
• sling.servlet.selectors
• sling.servlet.extensions
• sling.servlet.methods
• sling.servlet.prefix

        A SlingServletResolver listens for Servlet{}services and - given the correct service registration properties - provides the servlets as resources in the (virtual) resource tree. Such servlets are provided as ServletResource instances which adapt to the javax.servlet.Servlet class.

        For a Servlet registered as an OSGi service to be used by the Sling Servlet Resolver, either or both of the sling.servlet.paths or the sling.servlet.resourceTypes service reference properties must be set. If neither is set, the Servlet service is ignored.

        Each path to be used for registration - either from the sling.servlet.paths property or constructed from the other sling.servlet.\* properties - must be absolute. Any relative path is made absolute by prefixing it with a root path. This prefix may be set with the sling.servlet.prefix service registration property. If this property is not set, the first entry in the ResourceResolver search path for the ResourceResolver.getResource(String) method is used as the prefix. If this entry cannot be derived, a simpe slash - / - is used as the prefix.

       If sling.servlet.methods is not specified, the servlet is only registered for handling GET requests. Make sure to list all methods you want to be handled by this servlet.

Registering a Servlet using Java Annotations

      If you are working with the default Apache Sling development stack you can use Java Annotations from Apache Felix Maven SCR Plugin to register your Sling servlets and describe their binding details.

sling.servlet.paths = \[ "/libs/sling/sample/html", "/libs/sling/sample/txt" \]
sling.servlet.resourceTypes = \[ "sling/unused" \]
sling.servlet.selectors = \[ "img" \]
sling.servlet.extensions = \[ "html", "txt", "json" \]

      These are the ways of doing , either with a Sling-specific @SlingServlet annotation or with the more generic maven-scr-plugin annotations etc..

1) The @SlingServlet annotation

@SlingServlet(
    resourceTypes = "sling/servlet/default",
    selectors = "hello",
    extensions = "html",
    methods = "GET")
public class MyServlet extends SlingSafeMethodsServlet {

    @Override
    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        ...
    }
}

2) The @Properties and @Property annotations

@Component(metatype = true)
@Service(Servlet.class)
@Properties({
    @Property(name = "sling.servlet.resourceTypes", value = "sling/servlet/default"),
    @Property(name = "sling.servlet.selectors", value = "hello"),
    @Property(name = "sling.servlet.extensions", value = "html"),
    @Property(name = "sling.servlet.methods", value = "GET")
})
public class MyServlet extends SlingSafeMethodsServlet {

    @Override
    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        ...
    }
}

Upon these we can define in following ways too

3) Registering the servlet by path

@SlingServlet(

    paths={"/services/unicom/v1/"}

)

@Properties({

    @Property(name="service.pid", value="com.adobe.unicom.v1.servlets.OmnnitureLoggingServlet",propertyPrivate=false),

    @Property(name="service.description",value="Omniture service call logging servlet", propertyPrivate=false),

    @Property(name="service.vendor",value="Adobe Systems Incorporated - Adobe@Adobe Team", propertyPrivate=false)

})

public class OmnnitureLoggingServlet extends SlingAllMethodsServlet

{

    @Override

    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException

    {

        //Do something fun here

    }

    @Override

    protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException

    {

        //Do something fun here

    }

}

4) Registering the servlet by resource type and extension

@SlingServlet(

    resourceTypes = {"rep:User"},

    methods = {"GET", "POST"}

)

@Properties({

    @Property(name="service.pid", value="com.adobe.unicom.v1.servlets.OmnnitureLoggingServlet",propertyPrivate=false),

    @Property(name="service.description",value="Omniture service call logging servlet", propertyPrivate=false),

    @Property(name="service.vendor",value="Adobe Systems Incorporated - Adobe@Adobe Team", propertyPrivate=false)

})

public class OmnnitureLoggingServlet extends SlingAllMethodsServlet

{

    @Override

    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException

    {

        //Do something fun here

    }

    @Override

    protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException

    {

        //Do something fun here

    }

}

5) handle all requests and filter on selector you can change the example above to read something like this.

@SlingServlet(

    resourceTypes = {"sling/servlet/default"},

    methods = {"GET"},

    selectors = {"report"},

    extensions = {"json"}

)

@Properties({

    @Property(name="service.pid", value="com.adobe.unicom.v1.servlets.OmnnitureLoggingServlet",propertyPrivate=false),

    @Property(name="service.description",value="Omniture service call logging servlet", propertyPrivate=false),

    @Property(name="service.vendor",value="Adobe Systems Incorporated - Adobe@Adobe Team", propertyPrivate=false)

})

public class OmnnitureLoggingServlet extends SlingAllMethodsServlet

{

........

}

6) To handle all requests for a Page with a special selector.




ie http://www.demosample.com/content/page.mycustomselector.html  

@SlingServlet(

    resourceTypes = {"cq:Page"},

    methods = {"GET"},

    selectors = {"mycustomselector"}

)

@Properties({

    @Property(name="service.pid", value="com.adobe.unicom.v1.servlets.OmnnitureLoggingServlet",propertyPrivate=false),

    @Property(name="service.description",value="Omniture service call logging servlet", propertyPrivate=false),

    @Property(name="service.vendor",value="Adobe Systems Incorporated - Adobe@Adobe Team", propertyPrivate=false)

})

public class OmnnitureLoggingServlet extends SlingAllMethodsServlet

{

........

}

7) To handle all requests for a Page with a special extension.

ie http://www.demosample.com/content/page.mydemoext 

@SlingServlet(

    resourceTypes = {"cq:Page"},

    methods = {"GET"},

    extensions = {"mydemoext"}

)

@Properties({

    @Property(name="service.pid", value="com.adobe.unicom.v1.servlets.OmnnitureLoggingServlet",propertyPrivate=false),

    @Property(name="service.description",value="Omniture service call logging servlet", propertyPrivate=false),

    @Property(name="service.vendor",value="Adobe Systems Incorporated - Adobe@Adobe Team", propertyPrivate=false)

})

public class OmnnitureLoggingServlet extends SlingAllMethodsServlet

{

........

}

By following these can define/achieve creation of servlets in cq5 as per our tech specs.  

     Here we can prefer resourceType for writing SlingServlets most efficiently.

Some of the reasons comes into picture while development phase itself.

There are :

• While defining a path , you must be specific what all paths are allowed to be used in the ServletResource OSGi service. If you define something randomly, your servlet might not be fucntional. Only a limited paths are allowed and the rest are blocked unless you open them up. This is resolved using resourceType.
• You may have also configure the dispatcher , if you use some random path for your servlet. This might be a potential security threat and a needless configuration.
• You might also have to specify the paths to your consumers for your servlet and any change in that path could have a serious affect. This might not be the case when you use resourceType

References : http://hashimkhan.in/ , https://sling.apache.org/documentation/the-sling-engine/servlets.html , http://blogs.adobe.com/aaa/

Hope it helps :)

Thanks,
SonyCharan

Instagram feed component in cq5

        For this, You can create a custom Adobe CQ data feed component that retrieves external data and displays the data within a CQ web page. For example, a CQ component can retrieve data from an Instagram feed to let your users view current forum data. Likewise, a CQ component can retrieve data from a social site like Twitter to keep your users updated with the latest social data.

Here we are creating a custom component that can show the Instagram feed data :

       Once added to the CQ sidekick, a CQ author can drag and drop it onto a CQ page during design time. You create a Twitter feed component by integrating the Twitter API into Adobe CQ (shown in this development article).

Create a CQ component that integrates with the Twitter API by performing these steps:

1. Create an Adobe CQ application folder structure.
2. Create a template on which the render component is based.
3. Create a render component that displays the CQ sidekick.
4. Get the Instagram widget code to use in your AEM application.
5. Create a site that contains a page that displays Instagram data.

Here is the dialog for the custom Instagram feed component.

Dialog for Instagram feed component in cq5

          After adding a dialog , we need to define the jsp file for it. And in that we can use a script as follows to generate the feed. This feed can be generated by using the userid and accessToken provide by the user.

Here is the script, (this will fetch the data by using the instafeed.min.js which is shared by the instagram itself)

<script type="text/javascript">

      var userFeed = new Instafeed({

                     get: 'user',

                     userId: 'xxxxxxxx',

                     accessToken: 'xxxxxxxxx.xxxxx.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'

      });

      userFeed.run();

</script>

By this we can get output as a JSON file as follows,

JSON file for instagram feed

By looping the JSON file we can retrieve the exact content that should be shown on page(Name, date, comment, image etc..).

So finally, we can loop the data as per the requirement. Once you got the JSON file means you are succeeded in getting the feed data, so play with it.

Creating a maven project in cq5

Here we are Setting up only project structure for CQ/AEM project using maven and development of AEM/CQ project with eclipse.

Configuring AEM Maven Archetype for Eclipse can be done by installing and adding AEM plugin to the existing eclipse IDE,

The manual setup for the Maven is as follows

PREREQUISITES TO SETUP

     To set up a development environment based on Maven the following software must be installed before starting:

•      Apache Maven 3.0.4 or higher
•      Oracle Java SE 1.5.x or higher
•      CQ5.5, AEM 5.6 or higher

Now follow these defined steps,

Create the initial structure from Adobe's multimodule-content-package-archetype

In your shell, go to a directory where your project is supposed to be created.

In the following example, line breaks are only to make reading simpler. Everything goes on one line.

$ mvn archetype:generate -DarchetypeRepository=http://repo.adobe.com/nexus/content/groups/public/ -DarchetypeGroupId=com.day.jcr.vault -DarchetypeArtifactId=multimodule-content-package-archetype -DarchetypeVersion=1.0.2 -DgroupId=my-group-id -DartifactId=myproject -Dversion=1.0-SNAPSHOT -Dpackage=com.mycompany.myproject -DappsFolderName=myproject -DartifactName="My Project" -DcqVersion="5.6.1" -DpackageGroup="My Company"

Confirm the provided values by entering "Y" and hitting Return when Maven asks.

Confirm properties configuration:

• groupId: my-group-id
• artifactId: myproject
• version: 1.0-SNAPSHOT
• package: com.mycompany.myproject
• appsFolderName: myproject
• artifactName: My Project
• cqVersion: 5.6.1
• packageGroup: My Company
•  Y: :

Now ,

Maven has created a directory for the project. Change into it:

       # cd myproject

Now build the project and install it into your AEM instance.

       # mvn -PautoInstallPackage install

By the above procedure, it should create different XML files for the project and content.

The archetype has created the following project definition for us.

myproject/pom.xml

<?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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <!-- ====================================================================== -->
    <!-- P A R E N T P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->

    <groupId>my-group-id</groupId>
    <artifactId>myproject</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <name>My Project - Reactor Project</name>
    <description>Maven Multimodule project for My Project.</description>

    <prerequisites>
        <maven>3.0.2</maven>
    </prerequisites>

    <!-- ====================================================================== -->
    <!-- P R O P E R T I E S -->
    <!-- ====================================================================== -->
    <properties>
        <crx.host>localhost</crx.host>
        <crx.port>4502</crx.port>
        <crx.username>admin</crx.username>
        <crx.password>admin</crx.password>
        <publish.crx.host>localhost</publish.crx.host>
        <publish.crx.port>4503</publish.crx.port>
        <publish.crx.username>admin</publish.crx.username>
        <publish.crx.password>admin</publish.crx.password>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.osgi</groupId>
                <artifactId>org.osgi.core</artifactId>
                <version>4.2.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.osgi</groupId>
                <artifactId>org.osgi.compendium</artifactId>
                <version>4.2.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.felix</groupId>
                <artifactId>org.apache.felix.scr.annotations</artifactId>
                <version>1.6.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>biz.aQute</groupId>
                <artifactId>bndlib</artifactId>
                <version>1.43.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
                <version>1.5.10</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>javax.jcr</groupId>
                <artifactId>jcr</artifactId>
                <version>2.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.sling</groupId>
                <artifactId>org.apache.sling.api</artifactId>
                <version>2.2.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.sling</groupId>
                <artifactId>org.apache.sling.jcr.api</artifactId>
                <version>2.1.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.8.1</version>
                <scope>test</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <!--
        Inclusion of repositories in POMs is controversial, to say the least.
        It would be best if you proxied the Adobe repository using a Maven
        Repository Manager. Once you do that, remove these sections.
     -->
    <repositories>
        <repository>
            <id>adobe</id>
            <name>Adobe Public Repository</name>
            <url>http://repo.adobe.com/nexus/content/groups/public/</url>
            <layout>default</layout>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>adobe</id>
            <name>Adobe Public Repository</name>
            <url>http://repo.adobe.com/nexus/content/groups/public/</url>
            <layout>default</layout>
        </pluginRepository>
    </pluginRepositories>

    <build>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.felix</groupId>
                    <artifactId>maven-scr-plugin</artifactId>
                    <version>1.7.4</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.felix</groupId>
                    <artifactId>maven-bundle-plugin</artifactId>
                    <version>2.3.7</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.1</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>2.6</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.7</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.4</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.14.1</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-javadoc-plugin</artifactId>
                    <version>2.9</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.sling</groupId>
                    <artifactId>maven-sling-plugin</artifactId>
                    <version>2.1.0</version>
                    <configuration>
                        <username>${crx.username}</username>
                        <password>${crx.password}</password>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>com.day.jcr.vault</groupId>
                    <artifactId>content-package-maven-plugin</artifactId>
                    <version>0.0.20</version>
                    <extensions>true</extensions>
                    <configuration>
                        <failOnError>true</failOnError>
                        <username>${crx.username}</username>
                        <password>${crx.password}</password>
                    </configuration>
                </plugin>
                <!--This plugin's configuration is used to store Eclipse
                    m2e settings only. It has no influence on the Maven build itself. -->
                <plugin>
                    <groupId>org.eclipse.m2e</groupId>
                    <artifactId>lifecycle-mapping</artifactId>
                    <version>1.0.0</version>
                    <configuration>
                        <lifecycleMappingMetadata>
                            <pluginExecutions>
                                <pluginExecution>
                                    <pluginExecutionFilter>
                                        <groupId>
                                            org.apache.felix
                                        </groupId>
                                        <artifactId>
                                            maven-scr-plugin
                                        </artifactId>
                                        <versionRange>
                                            [1.0.0,)
                                        </versionRange>
                                        <goals>
                                            <goal>scr</goal>
                                        </goals>
                                    </pluginExecutionFilter>
                                    <action>
                                        <ignore/>
                                    </action>
                                </pluginExecution>
                            </pluginExecutions>
                        </lifecycleMappingMetadata>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

    <profiles>
        <profile>
            <id>autoInstallBundle</id>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.sling</groupId>
                        <artifactId>maven-sling-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>install-bundle</id>
                                <goals>
                                    <goal>install</goal>
                                </goals>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
  <modules>
    <module>bundle</module>
    <module>content</module>
  </modules>
</project>

THE BUNDLE MODULE

The bundle module is set up to contain OSGi Services required in your project.

Note that depending on the complexity of your project, you may want to refine this setup and create separate modules for individual areas of your project. For example, it is common to have a separate bundle for the project specific tag library, and to separate infrastrutural components (loggers, filters, login modules, etc) from business components (workflow steps, live action factories, content builders and transport handlers, etc).

The following structure has been created by the Maven archetype.

+-- pom.xml
+-- src
    +-- main
    ¦   +-- java
    ¦       +-- com
    ¦           +-- mycompany
    ¦               +-- myproject
    ¦                   +-- HelloService.java
    ¦                   +-- impl
    ¦                   ¦   +-- HelloServiceImpl.java
    ¦                   ¦   +-- filters
    ¦                   ¦       +-- LoggingFilter.java
    ¦                   +-- package-info.java
    +-- test
        +-- java
            +-- com
                +-- mycompany
                    +-- myproject
                        +-- SimpleUnitTest.java


Below is the Bundle POM file generated by the Maven archetype.

myproject/bundle/pom.xml

<?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/maven-v4_0_0.xsd ">
    <modelVersion>4.0.0</modelVersion>
    <!-- ====================================================================== -->
    <!-- P A R E N T P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->
    <parent>
        <groupId>my-group-id</groupId>
        <artifactId>myproject</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <!-- ====================================================================== -->
    <!-- P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->

    <artifactId>myproject-bundle</artifactId>
    <packaging>bundle</packaging>
    <name>My Project Bundle</name>

    <dependencies>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.compendium</artifactId>
        </dependency>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.felix</groupId>
            <artifactId>org.apache.felix.scr.annotations</artifactId>
        </dependency>
        <dependency>
            <groupId>biz.aQute</groupId>
            <artifactId>bndlib</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.jcr</groupId>
            <artifactId>jcr</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.sling</groupId>
            <artifactId>org.apache.sling.api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.sling</groupId>
            <artifactId>org.apache.sling.jcr.api</artifactId>
        </dependency>
    </dependencies>

    <!-- ====================================================================== -->
    <!-- B U I L D D E F I N I T I O N -->
    <!-- ====================================================================== -->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-scr-plugin</artifactId>
                <executions>
                    <execution>
                        <id>generate-scr-descriptor</id>
                        <goals>
                            <goal>scr</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <Bundle-SymbolicName>my-group-id.myproject-bundle</Bundle-SymbolicName>
                    </instructions>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.sling</groupId>
                <artifactId>maven-sling-plugin</artifactId>
                <configuration>
                    <slingUrl>http://${crx.host}:${crx.port}/apps/myproject/install</slingUrl>
                    <usePut>true</usePut>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                 <configuration>
                    <excludePackageNames>
                        *.impl
                    </excludePackageNames>
                 </configuration>
            </plugin>
        </plugins>
    </build>
</project>

THE CONTENT MODULE

The content module is set up to build an AEM content package which combines

components
templates
configurations
sample content
the OSGi bundle that is built by the bundle module
The archetype provides the structure below. As you can see, it deviates a little from a standard Maven Java module as there are no Java sources in the context of a content module. Accordingly, the module contains a directory src/main/content.

+-- pom.xml
+-- src
    +-- main
        +-- content
            +-- META-INF
            ¦   +-- vault
            ¦       +-- config.xml
            ¦       +-- definition
            ¦       ¦   +-- .content.xml
            ¦       +-- filter.xml
            ¦       +-- nodetypes.cnd
            ¦       +-- properties.xml
            +-- jcr_root
                +-- apps
                    +-- myproject
                        +-- config
                        ¦   +-- put-your-configs-here.txt
                        +-- install
                            +-- .vltignore
                            +-- bundle-will-go-here.txt


The POM generated by the archetype has a couple of noteworthy points.

The content-package-maven-plugin is configured to embed the OSGi bundle at /apps/myproject/install, (where Apache Sling's JCR Installer Provider will pick it up and install it with the OSGi Installer)
It is also configured to install the package at the host and port configured in the parent pom
By default, the content-package-maven-plugin uses the project's resources definition.
Depending on your other development tools, you may want to exclude more files, such as .git, .project etc.
A profile autoInstallPackage is defined, which binds the content-package-maven-plugin's install goal to Maven's install phase. This profile allows you to automatically install the package to AEM after it has been built.
A profile autoInstallPackagePublish is defined, which does the same for a publish server

myproject/content/pom.xml

<?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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <!-- ====================================================================== -->
    <!-- P A R E N T P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->
    <parent>
        <groupId>my-group-id</groupId>
        <artifactId>myproject</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <!-- ====================================================================== -->
    <!-- P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->

    <artifactId>myproject-content</artifactId>
    <packaging>content-package</packaging>
    <name>My Project Package</name>

    <dependencies>
        <dependency>
            <groupId>${project.groupId}</groupId>
            <artifactId>myproject-bundle</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>
    <build>
        <resources>
            <resource>
                <directory>src/main/content/jcr_root</directory>
                <filtering>false</filtering>
                <excludes>
                    <exclude>**/.vlt</exclude>
                    <exclude>**/.vltignore</exclude>
                </excludes>
            </resource>
        </resources>

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <configuration>
                    <includeEmptyDirs>true</includeEmptyDirs>
                </configuration>
            </plugin>

            <plugin>
                <groupId>com.day.jcr.vault</groupId>
                <artifactId>content-package-maven-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <group>My Company</group>
                    <filterSource>src/main/content/META-INF/vault/filter.xml</filterSource>
                    <embeddeds>
                        <embedded>
                            <groupId>${project.groupId}</groupId>
                            <artifactId>myproject-bundle</artifactId>
                            <target>/apps/myproject/install</target>
                        </embedded>
                    </embeddeds>
                    <targetURL>http://${crx.host}:${crx.port}/crx/packmgr/service.jsp</targetURL>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <profiles>
        <profile>
            <id>autoInstallPackage</id>
            <build>
                <plugins>
                    <plugin>
                        <groupId>com.day.jcr.vault</groupId>
                        <artifactId>content-package-maven-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>install-content-package</id>
                                <phase>install</phase>
                                <goals>
                                    <goal>install</goal>
                                </goals>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
        <profile>
            <id>autoInstallPackagePublish</id>
            <build>
                <plugins>
                    <plugin>
                        <groupId>com.day.jcr.vault</groupId>
                        <artifactId>content-package-maven-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>install-content-package-publish</id>
                                <phase>install</phase>
                                <goals>
                                    <goal>install</goal>
                                </goals>
                                <configuration>
                                    <targetURL>http://${publish.crx.host}:${publish.crx.port}/crx/packmgr/service.jsp</targetURL>
                                    <username>${publish.crx.username}</username>
                                    <password>${publish.crx.password}</password>
                                </configuration>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
</project>

Typical Steps in a Development Cycle

CONTENT PACKAGE DEVELOPMENT TASKS

The typical development cycle for your content package is to

• make changes to the project, either on the filesystem or in the repository
• run mvn -PautoInstallPackage clean install to deploy the package to the repository
• Making Changes to the Project

You can make changes to the content/ project in two ways:

• Make changes below content/src/main/content/jcr_root and deploy them to the repository
• Make changes in the repository and use the vlt tool to sync them back to the filesystem

mvn -PautoInstallPackage clean install

Running mvn -PautoInstallPackage clean install will

• build the content package according to the definition in myproject/content/pom.xml and save that package to content/target/myproject-content-1.0-SNAPSHOT.zip
• install the package into your local maven repository (that is what Maven's "install" phase always does)
• activate the autoInstallPackage profile of the content module, which binds the content-package-maven-plugin:install goal to the install phase and so installs the package into AEM through the Package Manager's HTTP API. See the documentation of the Content Package Maven Plugin for details.

BUNDLE DEVELOPMENT TASKS

The bundle module follows a standard Java setup, and so does the process:

• make changes to your Java sources
• run mvn -PautoInstallBundle install in the bundle/ directory to compile and deploy the bundle

And Further,

VLT is used to keep the file system and the repository synchronized. The basic steps for setting this up are

• install the package to your repository
• cd to content/src/main/content/jcr_root
• run vlt co --force http://localhost:4502/ -- this will check out the content from the repository into your filesystem and set up vlt to keep track
• run vlt sync install -- this will install the vlt sync service into your repository if not already available
• run vlt sync register -- this will register this project's directory with the vlt sync service

We can setup appropriate vlt commands to keep the system up to date. For this you need to configure the XML file accordingly.

Hope it helps :)

Thanks,
SonyCharan