Support Questions

Find answers, ask questions, and share your expertise

I'm totally new to Nifi. I'm using ExtractHL7Attributes to get hl7 data and trying to convert it into FHIR Patient format and push it to a FHIR service. Any thoughts would be really helpful.

Here's how i configured the ExtractHL7Attributes processor,


The attributes after parsing a sample hl7 file seen from data provenance of ExtractHL7Attributes processor,


How can i get these attribute values and process it ?

Do i need to add another processor, use expression language in properties of a processor ?


Expert Contributor

There are many processors you can use to continue your NiFi flow. I mocked up your scenario and was able to use the AttributesToJSON processor to convert all of the data into a JSON format. In that processor, you can optionally specify which columns of data inside the FlowFile you want to keep. This is one such example - you can research and experiment with many of the other processors to do data filtering and processing.

My mock NiFi flow read from a Kafka stream, used the ExtractHL7Attributes processor, converted to JSON using the AttributesToJSON processor, and wrote that data to HDFS. Let me know if I can help you out with any specific part of that chain.

@anarasimham Thanks for the great answer.

I've used AttributesToJSON to convert it to JSON format. But i wasn't able to manipulate it to desired structure(when i used JoltTransformJSON). You can view my another question related to that in this link (

In between if you can share the knowledge on how to use a kafka and HDFS in NiFi, it would be really helpful.

Expert Contributor

Sure - I wrote an article since others may want to know this information. You can check it out here:

Let me know if you have any other questions, happy to answer.