How to invoke another OSGI bundle servlet from different OSGI bundle?

[Former Community Member]

Hi there,

i just wondering How to invoke another OSGI bundle servlet from different OSGI bundle?

Thanks a lot.

Best regards,

Brian

[bfvaughn]

Servlets are registered services in OSGi so you can access it just like a service. If you have shared logic, its probably better to move that code into a class you can define as an OSGi service.

[smacdonald2008]

IN CQ 5.6 - you have access to this API:

Package org.apache.commons.httpclient

Here is this API showing up the AEM Dependency Finder:

[img]cleinthttp.png[/img]

So you can code a custom service in the OSGi that can use an object of type org.apache.commons.httpclient.HttpClient to send an HTTP request to an AEM Sling Servlet.  

Also - here is the Maven dependency you need:

<dependency>
    <groupId>com.day.commons.osgi.wrapper</groupId>
    <artifactId>com.day.commons.osgi.wrapper.commons-httpclient</artifactId>
    <version>3.1.0.018</version>
    <scope>provided</scope>
</dependency>

[smacdonald2008]

If you want to invoke an AEM servlet from another OSGi within the same AEM instance (as opposed to using Service injection), you can use Java org.apache.http.client.methods API. See:

http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/client/methods/pack...

[Former Community Member]

Hi scott,

Thanks for your comments. and the question is if AEM support third party httpclient.jar dependency well?

Thanks a lot.

Best regards,

Brian

[Former Community Member]

hi scott,

i did it following your suggestion. However, maven can't download the jar com.day.commons.osgi.wrapper.commons-httpclient-3.1.0.018.jar

i don't know how to deal with it.  Details please see below screenshot.

[img]httpclient.png[/img]

Thanks a lot.

[smacdonald2008]

What you do is inject service A (defined in bundle X) into service B (defined in bundle Z). If you are not familiar with how to perform dependency injection - see this article:

 Injecting a DataSourcePool Service into an Adobe Experience Manager OSGi bundle

[smacdonald2008]

To get the aem http client api to work with maven, you have to add the following elements to your POM file. This pulls from the adobe repos

<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>

[Former Community Member]

Hi Scott,

After add that elements to my POM file, it happened the error either as before.

[img]httpclient.png[/img]

So weird here.

Best regards,

Brian

[smacdonald2008]

I will have a community article that shows you HOW TO use org.apache.commons.httpclient APIS in AEM - including how to build the OSGi and how to use it to invoke a Sling Servlet within AEM. This will be posted sometime in the next day. 

[smacdonald2008 · Accepted solution]

I got this use case to work. The following pic shows an AEM web page that displays data returned from a Sling Servlet (the Sling Servlet invoked by an AEM Service):

[img]SlingInvoke.png[/img]

Here is the community article that steps you through this use case:

https://helpx.adobe.com/experience-manager/using/HttpClient_AEM.html

Only use this use case if you have to invoke a servlet from a service. It better to invoke the servlet from a web page using AJAX - as talked about here:

http://helpx.adobe.com/experience-manager/using/custom-sling-servlets.html

[Former Community Member]

When i delete below element within POM file, run maven command "mvn clean install" very well.

<dependency> <groupId>com.day.commons.osgi.wrapper</groupId> <artifactId>com.day.commons.osgi.wrapper.commons-httpclient</artifactId> <version>3.1.0.018</version> <scope>provided</scope> </dependency>

However, if i add the above element within POM file, run maven command appears error as below immediately.

[img]mvnerror.png[/img]