Creating your own implementation is done using Java. You have to extend the ICommitter interface. Abstract classes can help you get started. Have a look at the AbstractBatchCommitter class, which handles queuing of documents, sending in batches, as well as mapping original document metadata with your repository fields.
If you are using Maven, simply add the Committer
project dependency to your pom.xml.
If you are not using Maven, you can add all JAR files found within the
Committer zip file "lib" folder to your application classpath.
Refer to the Norconex Committer API Documentation for more documentation and options on available Committer classes you can use or extend. You can look at the source code of other committer implementations to help you get started.