Apache NiFi is an open source platform and gives developers the options to add their custom processor in the NiFi library. Follow these steps to create a custom processor.
Download Maven latest version from the link given below.
Add an environment variable named M2_HOME and set value as the installation directory of maven.
Download Eclipse IDE from the below link.
Open command prompt and execute Maven Archetype command.
> mvn archetype:generate
Search for the nifi type in the archetype projects.
Select org.apache.nifi:nifi-processor-bundle-archetype project.
Then from the list of versions select the latest version i.e. 1.7.1 for this tutorial.
Enter the groupId, artifactId, version, package, and artifactBaseName etc.
Then a maven project will be created having to directories.
Run the below command in nifi-<artifactBaseName>-processors directory to add the project in the eclipse.
mvn install eclipse:eclipse
Open eclipse and select import from the file menu.
Then select “Existing Projects into workspace” and add the project from nifi-<artifactBaseName>-processors directory in eclipse.
Add your code in public void onTrigger(ProcessContext context, ProcessSession session) function, which runs when ever a processor is scheduled to run.
Then package the code to a NAR file by running the below mentioned command.
mvn clean install
A NAR file will be created at nifi-
Copy the NAR file to the lib folder of Apache NiFi and restart the NiFi.
After successful restart of NiFi, check the processor list for the new custom processor.
For any errors, check ./logs/nifi.log file.