HL7 DataFormat

The HL7 component ships with a HL7 data format that can be used to marshal or unmarshal HL7 model objects.

  • marshal = from Message to byte stream (can be used when responding using the HL7 MLLP codec)
  • unmarshal = from byte stream to Message (can be used when receiving streamed data from the HL7 MLLP

To use the data format, simply instantiate an instance and invoke the marshal or unmarshal operation in the route builder:

  DataFormat hl7 = new HL7DataFormat();
  ...
  from("direct:hl7in").marshal(hl7).to("jms:queue:hl7out");

In the sample above, the HL7 is marshalled from a HAPI Message object to a byte stream and put on a JMS queue.
The next example is the opposite:

  DataFormat hl7 = new HL7DataFormat();
  ...
  from("jms:queue:hl7out").unmarshal(hl7).to("patientLookupService");

Here we unmarshal the byte stream into a HAPI Message object that is passed to our patient lookup service.

Serializable messages

As of HAPI 2.0 (used by Camel 2.11), the HL7v2 model classes are fully serializable. So you can put HL7v2 messages directly into a JMS queue (i.e. without calling marshal() and read them again directly from the queue (i.e. without calling unmarshal().

Segment separators

As of Camel 2.11, unmarshal does not automatically fix segment separators anymore by converting \n to \r. If you
need this conversion, org.apache.camel.component.hl7.HL7#convertLFToCR provides a handy Expression for this purpose.

Charset

As of Camel 2.14.1, both marshal and unmarshal evaluate the charset provided in the field MSH-18. If this field is empty, by default the charset contained in the corresponding Camel charset property/header is assumed. You can even change this default behavior by overriding the guessCharsetName method when inheriting from the HL7DataFormat class.

 

There is a shorthand syntax in Camel for well-known data formats that are commonly used.
Then you don't need to create an instance of the HL7DataFormat object:

  from("direct:hl7in").marshal().hl7().to("jms:queue:hl7out");
  from("jms:queue:hl7out").unmarshal().hl7().to("patientLookupService");

 

 

  • No labels