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.

    1. > 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.

      • nifi-<artifactBaseName>-processors

      • nifi-<artifactBaseName>-nar

    • Run the below command in nifi-<artifactBaseName>-processors directory to add the project in the eclipse.

    1. 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.

    1. mvn clean install
    • A NAR file will be created at nifi--nar/target directory.

    • 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.