In a previous post I explored how to create a custom HCI adapter.  That is good if you have some very specific needs but most often you can just reuse an existing Camel component.  There are many Camel components already (just check which ones are compatible with your HCI tenant version).

The aim is to retrieve a Gmail profile but really you can also get messages, labels etc if you want.  I've decided to use the GoogleMail component.  The process is relatively easy:

• Create OSGi bundle for dependent libraries
• Create the HCI adapter and modify the metadata.xml
• Create a test integration project to see how it works.

Create OSGi bundle

If the Camel component has dependencies on other 3rd party libraries then they need to be deployed with the adapter.  The way to do it is to create an OSGi bundle that contains all the dependent libraries.  Later this OSGi bundle will be imported into the adapter project.

Check dependencies

The easiest way to see the dependencies is to open the pom.xml in Eclipse and click the Dependency Hierarchy tab.  Below is the dependencies camel-google-mail jar has:

Create a new project

Follow the HCI doco for this part (I'll just do it here with a few screenshots).

Instruction	Screenshot
In Eclipse, go to Start of the navigation path File Next navigation step New Next navigation step Project End of the navigation path. In the New Project wizard, search for Plug-in Development and select Plug-in from Existing JAR Archives. Choose Next.
If you have the JAR in the current workspace, then choose Add and select the JAR file from the JAR selection dialog. If you do not have the JAR in your current workspace, then choose Add External and select the required JAR file from your local system. Choose Next.
In the Plug-in Project Propertiesdialog, specify a name in the Project name field. In the Execution Environment drop down list box, select any java version that is less than or equal to JavaSE-1.7. In the Target Platform, select an OSGi framework option. Choose Finish.
Select the MANIFEST.MF file of your project, and go to Runtime tab. Choose Add. Select the required export packages. Choose OK and save the MANIFEST.MF file.
Right Click on the project and choose Export. In the Export wizard search for plug-in Development and choose Deployable plug-ins and fragments. Choose Next.
Choose Browse and select the directory where you want the plug-in to be generated. Choose Finish.

Create the HCI adapter

The next step is to create a new HCI adapter project.  Open Eclipse and select File > New > Other..  Expand the SAP HANA Cloud Integration section and select Adapter Project

click Next

click Finish

Now we need to do a bit of copy/paste.

• Copy the google-mail-library.x.jar that was exported in the previous step and paste it in the gmail-adapter\libs folder.
• Locate the camel-google-mail-x.jar (central repo or in your local maven repo) and paste it to the gmail-adapter\component folder.

Lastly right click the gmail-adapter project and select Generate Component Metadata.  The resulting project should look like this:

Modify metadata.xml

Modify the metadata.xml file by adding the <Varian> element.  Make sure your metadata.xml looks like below:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><ComponentMetadata ComponentId="ctype::Adapter/cname::apache:google-mail/version::1.0.0" ComponentName="apache:google-mail" UIElementType="Adapter" IsExtension="false" IsFinal="true" IsPreserves="true" IsDefaultGenerator="true" MetadataVersion="2.0" xmlns:gen="http://www.sap.hci.adk.com/gen">  <Variant VariantName="Get Profile" gen:RuntimeComponentBaseUri="google-mail" VariantId="ctype::AdapterVariant/cname::apache:google-mail/tp::https/mp::none/direction::Receiver" IsRequestResponse="true" MetadataVersion="2.0" AttachmentBehavior="Preserve">  <InputContent Cardinality="1" Scope="outsidepool" MessageCardinality="1" isStreaming="false">  <Content>  <ContentType>Any</ContentType>  <Schema xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></Schema>  </Content>  </InputContent>  <OutputContent Cardinality="1" Scope="outsidepool" MessageCardinality="1" isStreaming="false">  <Content>  <ContentType>Any</ContentType>  <Schema xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></Schema>  </Content>  </OutputContent>  <Tab id="connection">  <GuiLabels guid="8c1e4365-b434-486a-8ec8-2a8fd370f77f">  <Label language="EN">Connection</Label>  <Label language="DE">Connection</Label>  </GuiLabels>  <AttributeGroup id="defaultUriParameter">  <Name xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">URI Setting</Name>  <GuiLabels guid="d1004d88-8e54-4f46-a5e7-e6e4d0dca053">  <Label language="EN">URI Setting</Label>  <Label language="DE">URI Setting</Label>  </GuiLabels>  <AttributeReference>  <ReferenceName>firstUriPart</ReferenceName>  <description>Configure First URI Part</description>  </AttributeReference>  <AttributeReference>  <ReferenceName>userId</ReferenceName>  <description>Gmail User Id</description>  </AttributeReference>  </AttributeGroup>  <AttributeGroup id="googleMailEndpoint">  <Name xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Google Mail Endpoint</Name>  <GuiLabels guid="7a914dcf-ab5e-4dfc-a859-d4709bd7402d">  <Label language="EN">Google Mail Endpoint</Label>  <Label language="DE">Google Mail Endpoint</Label>  </GuiLabels>  <AttributeReference>  <ReferenceName>clientId</ReferenceName>  <description>Client Id</description>  </AttributeReference>  <AttributeReference>  <ReferenceName>clientSecret</ReferenceName>  <description>Client Secret</description>  </AttributeReference>  <AttributeReference>  <ReferenceName>accessToken</ReferenceName>  <description>Acess Token</description>  </AttributeReference>  <AttributeReference>  <ReferenceName>refreshToken</ReferenceName>  <description>Refresh Token</description>  </AttributeReference>  </AttributeGroup>  </Tab>  </Variant>  <AttributeMetadata>  <Name>firstUriPart</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="d78fa735-e35e-49f1-95cb-a82b075615be">  <Label language="EN">First URI Part</Label>  <Label language="DE">First URI Part</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>userId</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="71bcdd72-6b26-4423-b684-76d1ef626ca1">  <Label language="EN">Gmail User Id</Label>  <Label language="DE">Gmail User Id</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>clientId</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <AttributeBehavior>SecureAlias</AttributeBehavior>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="71bcdd72-6b26-4423-b684-76d1ef626ca1">  <Label language="EN">Client Id</Label>  <Label language="DE">Client Id</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>clientSecret</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <AttributeBehavior>SecureAlias</AttributeBehavior>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="dbf6df69-7666-46e5-9aaf-074d2fc0a080">  <Label language="EN">Client Secret</Label>  <Label language="DE">Client Secret</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>accessToken</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <AttributeBehavior>SecureAlias</AttributeBehavior>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="b8748d93-076c-46cb-b694-c84f6cd3095c">  <Label language="EN">Access Token</Label>  <Label language="DE">Access Token</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>applicationName</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="c17aa8da-765e-417c-987f-b06f7aabd4bf">  <Label language="EN">Application Name</Label>  <Label language="DE">Application Name</Label>  </GuiLabels>  </AttributeMetadata>  <AttributeMetadata>  <Name>refreshToken</Name>  <Usage>false</Usage>  <DataType>xsd:string</DataType>  <Default></Default>  <Length></Length>  <AttributeBehavior>SecureAlias</AttributeBehavior>  <IsParameterized>true</IsParameterized>  <GuiLabels guid="5373e7c4-cd24-40b8-957b-bc37f32376f7">  <Label language="EN">Refresh Token</Label>  <Label language="DE">Refresh Token</Label>  </GuiLabels>  </AttributeMetadata></ComponentMetadata>

Again, the parameters are secured.  To ensure all is good right click the project and select Execute Checks.  You should see the following in the console:

[9/05/16 3:49 PM] Checks executed successfully

And finally do a local build.  Right click the project and select Build Adapter Project.  Your should see the following in the console:

[9/05/16 3:51 PM] Build completed

Create a test integration project

Create a new integration project called google-mail-integration.  The outcome should be as follows:

Select the Channels tab and click on Browse.  If all went well you will see the google-mail adapter as an option in the dialog.  Select the google-mail option.

Select the Adapter Specific tab and enter details as required.  As you can see I am using secured parameters

You can also use some other endpoint prefix, see     Apache Camel: GoogleMail   

Deploy the HCI adapter

Deploy to your HCI tenant and check it deployed successfully.

Missing dependencies will throw an exception similar to this:

org.osgi.service.subsystem.SubsystemException: org.osgi.service.resolver.ResolutionException: Unable to resolve /tmp/inputStreamExtract2522187002793448101.zip/camel-google-mail-2.16.2.jar: missing requirement org.apache.aries.subsystem.core.archive.ImportPackageRequirement: namespace=osgi.wiring.package, attributes={}, directives={filter=(&(osgi.wiring.package=com.google.api.client.http.javanet)(version>=0.0.0))}, resource=/tmp/inputStreamExtract2522187002793448101.zip/camel-google-mail-2.16.2.jar

 

Go back and ensure the missing lib is in the OSGi bundle.

Deploy the integration project

Deploy the google-mail-integration project to your tenant and monitor the messages.  If everything worked you will see something like this

Conclusion

So it is much easier to use an existing Camel component than creating your own from scratch.  And although this example does not do anything significant it shows how to create an adapter using Camel components.