How to create a Mule SDK Custom Connector compatible with JDK 17?

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Overview:

In this blog post, we’ll create a basic Mule SDK based custom connector for JDK 17. We’ll publish it to exchange as well and try to use it in Mule App running on Java 17.

Prerequisites:

1. Anypoint Studio: 7.17 Configured to use JDK 17
2. Open JDK 8
3. Maven 3.9.6

Task 1: Setup your settings.xml file

Add the server tag in settings.xml file

<server>
    <id>exchange-server</id>
    <username>username</username>
    <password>********</password>
</server>

Add profiles in settings.xml file

<profile>
  <id>archetype-repository</id>
  <repositories>
   <repository>
    <id>archetype</id>
    <name>Mule Repository</name>
    <url>https://repository-master.mulesoft.org/nexus/content/repositories/public</url>
    <releases>
     <enabled>true</enabled>
     <checksumPolicy>fail</checksumPolicy>
    </releases>
    <snapshots>
     <enabled>true</enabled>
     <checksumPolicy>warn</checksumPolicy>
    </snapshots>
   </repository>
  </repositories>
 </profile>

 <profile>
  <id>mule-extra-repos</id>
  <activation>
   <activeByDefault>true</activeByDefault>
  </activation>
  <repositories>
   <repository>
    <id>mule-public</id>
    <url>https://repository.mulesoft.org/nexus/content/repositories/public</url>
   </repository>
  </repositories>
  <pluginRepositories>
   <pluginRepository>
    <id>mule-public</id>
    <url>https://repository.mulesoft.org/nexus/content/repositories/public</url>
   </pluginRepository>
  </pluginRepositories>
 </profile>

Task 2: Generate a project structure for custom connector

Select a folder and run the following command

mvn org.mule.extensions:mule-extensions-archetype-maven-plugin:generate

Provide the following details:

1. Enter the name of the extension (empty for default): demo
2. Enter the extension’s groupId (empty for default): com.personal.connectors
3. Enter the extension’s artifactId (empty for default): demo
4. Enter the extension’s version (empty for default): 1.0.0
5. Enter the extension’s main package (empty for default): Leave it blank

Task 3: Import the project into the Anypoint Studio

Configure the JDK 17 in Anypoint Studio by following below steps

Window -> Preferences -> Java -> Installed JREs

Click Apply and Close

For now, we can delete the test-mule-config.xml file and DemoOperationsTestCase.java

Task 4: Add the JavaVersionSupport to the custom connector to make it compatible with Java 17

<dependencies>
 <dependency>
  <groupId>org.mule.sdk</groupId>
  <artifactId>mule-sdk-api</artifactId>
  <version>0.7.0</version>
 </dependency>
</dependencies>

Now add the JavaVersionSupport annotation in the Extension.java file under src/main/java

Add @JavaVersionSupport({JavaVersion.JAVA_17, JavaVersion.JAVA_11, JavaVersion.JAVA_8}) in Extension.java file

Task 5: Maven Clean Install the connector and use it in the Mule App

Go to the project folder and run the below command

mvn clean install

Task 6: Add the connector to the Mule App running on Java 17

Add the following dependency to your Mule App

<dependency>
 <groupId>com.personal.connectors</groupId>
 <artifactId>demo</artifactId>
 <version>1.0.8</version>
 <classifier>mule-plugin</classifier>
</dependency>

Task 7: Publish the connector to Anypoint Exchange

Add the following repositories

<repositories>
  <repository>
   <id>exchange-server</id>
   <name>Corporate Repository</name>
   <url>https://maven.anypoint.mulesoft.com/api/v1/organizations/${project.groupId}/maven</url>
   <layout>default</layout>
  </repository>
  <repository>
   <id>anypoint-exchange-v3</id>
   <name>Anypoint Exchange V3</name>
   <url>https://maven.anypoint.mulesoft.com/api/v3/maven</url>
   <layout>default</layout>
  </repository>
 </repositories>
 
 <distributionManagement>
  <!-- Target Anypoint Organization Repository -->
  <repository>
   <id>exchange-server</id>
   <name>Corporate Repository</name>
   <url>https://maven.anypoint.mulesoft.com/api/v1/organizations/${project.groupId}/maven</url>
   <layout>default</layout>
  </repository>
 </distributionManagement>

Also change the project.groupId to Anypoint Platform orgId

<groupId>${orgId}</groupId>
<artifactId>demo</artifactId>
<version>1.0.8</version>

Run the following command

mvn clean deploy

This connector should run on the Mule Apps running on Java 17. I hope you’ve enjoyed learning about this topic. Please provide your feedback in the comments. Follow for more blogs and stay tuned for further insights!

References:

https://blogs.mulesoft.com/dev-guides/api-connectors-templates/custom-connector-mule-sdk/

https://docs.mulesoft.com/general/customer-connector-upgrade