Integration Suite - Developing Custom Adapters with IDE of Your Choice

[former_member481764]

Introduction

SAP Cloud Integration provides capability to add custom adapters to the Integration tooling via SAP ADK Framework.

If you are familiar with the adapter development using eclipse plugins, we offered the development of custom adapters with a dependency to Eclipse Oxygen. With January 2022 increment, we are providing more efficient and convenient way to develop custom adapters using any IDE of your choice.

With this increment, you shall be able to create a maven based project even for reusing an existing camel component.

In this blog, I am going to show you how to create the adapter using archetypes and different maven phases for metadata generation and build.

Pre-requisites

1. Aware of maven archetypes.


2. Aware of Apache Camel.


3. Aware of OSGi and OSGi subsystem specification. The Adapter you develop is an OSGi esa file with type as Composite. That means it has be self-contained. If you use any dependencies, they have to be bundled within this ESA.

 

Types of Adapter Projects

Creation of the adapter project uses maven archetypes. There are two archetypes available for adapter project creation.

Adapter Project based on New Component

In this type, you normally need to implement the camel component within the adapter project. A sample adapter with all the necessary classes and metadata for a component is generated during the project creation.

Maven coordinate - com.sap.cloud.adk:com.sap.cloud.adk.archetype-adapter

 

Adapter Project based on Existing Camel Component

This type can be used when you already have a camel component and you want to create the adapter based on this component. You can relate it to the non-maven adapter type in eclipse. Now this is also based on maven and hence normal maven lifecycle can be used to build the project.

Maven coordinate - com.sap.cloud.adk:com.sap.cloud.adk.archetype-adapter-component-reuse

You can either refer the component as a dependency in pom or manually copy the component jar into the project folder.

Enough theory! Let's create some adapters.

New Adapter Project Type

We are going to create the project using the below archetype. Following is the maven command reference

mvn archetype:generate -B -DarchetypeGroupId=com.sap.cloud.adk \

 -DarchetypeArtifactId=com.sap.cloud.adk.archetype-adapter \

 -DarchetypeVersion=1.0.1 \

 -DcomponentName=Greetings \

 -DadapterName=Greetings \

 -DadapterId=Greetings \

 -DadapterVendor=sap \

 -DadapterVersion=1.0.0 \

 -Dscheme=sap-greet \

 -DgroupId=com.sap.greet \

 -DartifactId=Greetings \

 -Dversion=1.0.0-SNAPSHOT

What are these command parameters mean?

Parameter Type	Parameters	Description
Archetype Parameters	archetypeArtifactId	Maven artifactId of archetype
	archetypeGroupId	Maven groupId of archetype
	archetypeVersion	Maven version of archetype
Adapter Parameters	adapterName	Name of adapter
	adapterId	ID of adapter
	adapterVendor	vendor name for your adapter
	adapterVersion	adapter version. Default value is 1.0.0
Camel component parameters	componentName	Camel component name. This will be used for the class names of the component
	scheme	Endpoint scheme name of your camel component.
Maven coordinates for Adapter project	groupId	Project groupId
	artifactId	Project artifactId
	version	Project version

You can either use the above archetype:generate command or any IDE of your choice to generate the project. Refer maven central repository for the latest version of the archetype.

Creation

I am using the Intellij IDE to generate the project. You can also use other IDEs like Eclipse or Visual Studio etc.

Providing the adapter parameters.

Clicking on the Finish button, adapter project is created.

A sample camel component is already generated for your. Let's briefly understand what each of these files mean.

1. GreetingsComponent - This is the component class implementation.


2. GreetingsConsumer - This is a polling consumer. It just adds a Hello string with current time stamp.


3. GreetingsProducer - This is the receiver implementation which converts the 'greetingsMessage' to upper case and also appends the exchange input to the final message.


4. GreetingsEndpoint - This is the camel endpoint class. Here you will see the variables configured for your adapter. In the generated class, you can see a variable 'greetingsMessage'.


5. GreetingsComponentTest - This is a junit test which asserts the producer and consumer logic.


6. metadata.xml - this is the metadata xml generated automatically for you (As sample). Observe that it has two fields or is firstUriPart which is by default. Another one is matching to your @UriParam i.e. ‘greetingsMessage’.

Building your Adapter

Use the maven build commands to build the adapter project.

mvn clean install

The ADK plugin comes with various useful maven goals. Below screenshot shows the various maven goals which can be used in the adapter development process.

 

In case you want to re-generate the component metadata, generate-cmd goal can be used.

mvn adapter-build-plugin:generate-cmd​

In the same way, if you want to generate the blueprint metadata, generate-bmd goal can be used.

mvn adapter-build-plugin:generate-bmd​

If you want to do a validation check on the project explicitly, you can run the check goal. However, the check is executed automatically as part of the install command.

mvn adapter-build-plugin:check

Note that all the options provided in the eclipse plugin are provided as maven goals.

Testing

Once the maven build is successful, the esa file is generated in target/build. The esa file can now be imported in web-ui and can be consumed in an integration flow.

Reused Component Project Type

Here let's build an adapter based on an existing camel component!

The project is created using the archetype. Below is the maven command reference.

mvn archetype:generate -B -DarchetypeGroupId=com.sap.cloud.adk \

 -DarchetypeArtifactId=com.sap.cloud.adk.archetype-adapter-component-reuse \

 -DarchetypeVersion=1.0.1 \

 -DadapterName=MyAdapter \

 -DadapterId=MyAdapter \

 -DadapterVendor=sap \

 -DadapterVersion=1.0.0 \

 -DgroupId=com.sap.sample \

 -DartifactId=MyAdapter \

 -Dversion=1.0.0-SNAPSHOT​

 

You can either use the above archetype:generate command or any IDE of your choice to generate the project. Refer maven central repository for the latest version of the archetype.

Creation

I am using the Intellij IDE as before to generate the project.


Adapter project details are given in the next page

The project is created as shown below



 

component - This is where the camel component to be placed.

libs - The dependent jars need to be placed here.

metadata - This folder will contain the generated metadata xml file.

As you can see, all these folders are currently empty.

Open the pom.xml file. Here, you can refer the camel component maven coordinates as shown below. This way, the component jar and their dependencies are automatically copied to the respective folders during maven build.I am using the camel-rabbitmq camel component to create my adapter.

Building Your Adapter

Let us build the adapter using maven install command.

mvn clean install

After the successful build, you can observe the following:

• camel-rabbitmq component has been copied to the component folder.


• The dependent bundles have been placed under the libs folder.


• metadata.xml has been generated for the component.


• The esa has been generated.

If you want to place the component and dependent jars manually, you are free to do so. However you need to comment out the maven-dependency-plugin from the pom file.

 

If you already have a non-maven based adapter project which was created using the old eclipse plugin, you can manually convert it to new maven based project.

• Generate a new project using the reuse component project type. Provide same adapter name as your existing project.


• Comment out the maven-dependency-plugin from the pom file.


• Copy the component jar, dependent jars and the metadata file to the respective folders of new adapter.


• Build the adapter using maven.

Summary

In summary, we have seen how to create both types of adapter projects. Also seen what are the different maven goals available for the adapter development.