HL7 DataFormat

The HL7 component ships with a HL7 data format that can be used to format between String and HL7 model objects.

• marshal = from Message to byte stream (can be used when returning as response 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.

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.

Notice there is a shorthand syntax in Camel for well-known data formats that is 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");

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().