HL7Page edited by willem jiangHL7 ComponentThe hl7 component is used for working with the HL7 MLLP protocol and the HL7 model using the HAPI library. This component supports the following:
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-hl7</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
Exposing a HL7 listenerIn our Spring XML file, we configure an endpoint to listen for HL7 requests using TCP:
<endpoint id="hl7listener" uri="mina:tcp://localhost:8888?sync=true&codec=hl7codec"/>
Notice we configure it to use camel-mina with TCP on the localhost on port 8888. We use sync=true to indicate that this listener is synchronous and therefore will return a HL7 response to the caller. Then we setup mina to use our HL7 codec with codec=hl7codec. Notice that hl7codec is just a Spring bean ID, so we could have named it mygreatcodecforhl7 or whatever. The codec is also set up in the Spring XML file:
<bean id="hl7codec" class="org.apache.camel.component.hl7.HL7MLLPCodec">
<property name="charset" value="iso-8859-1"/>
</bean>
And here we configure the charset encoding to use, and iso-8859-1 is commonly used. The endpoint hl7listener can then be used in a route as a consumer, as this java DSL example illustrates:
from("hl7socket").to("patientLookupService");
This is a very simple route that will listen for HL7 and route it to a service named patientLookupService that is also a Spring bean ID we have configured in the Spring XML as:
<bean id="patientLookupService" class="com.mycompany.healtcare.service.PatientLookupService"/>
And another powerful feature of Camel is that we can have our busines logic in POJO classes that is not at all tied to Camel as shown here: public class PatientLookupService { public Message lookupPatient(Message input) throws HL7Exception { QRD qrd = (QRD)input.get("QRD"); String patientId = qrd.getWhoSubjectFilter(0).getIDNumber().getValue(); // find patient data based on the patient id and create a HL7 model object with the response Message response = ... create and set response data return response } Notice that this class is just using imports from the HAPI library and none from Camel. HL7 Model using java.lang.StringThe HL7MLLP codec uses plain String as data format. And Camel uses Type Converter to convert from/to strings to the HAPI HL7 model objects. However, you can use the plain String objects if you prefer, for instance if you need to parse the data yourself. See samples for such an example. HL7 Model using HAPIThe HL7 model is Java objects from the HAPI library. Using this library, we can encode and decode from the EDI format (ER7) that is mostly used with HL7. The ER7 sample below is a request to lookup a patient with the patient ID, 0101701234. MSH|^~\\&|MYSENDER|MYRECEIVER|MYAPPLICATION||200612211200||QRY^A19|1234|P|2.4 QRD|200612211200|R|I|GetPatient|||1^RD|0101701234|DEM|| Using the HL7 model we can work with the data as a ca.uhn.hl7v2.model.Message.Message object. Message msg = exchange.getIn().getBody(Message.class); QRD qrd = (QRD)msg.get("QRD"); String patientId = qrd.getWhoSubjectFilter(0).getIDNumber().getValue(); Camel has built-in type converters, so when this operation is invoked: Message msg = exchange.getIn().getBody(Message.class); Camel will convert the received HL7 data from String to Message. This is powerful when combined with the HL7 listener, then you as the end-user don't have to work with byte[], String or any other simple object formats. You can just use the HAPI HL7 model objects. HL7 DataFormatThe HL7 component ships with a HL7 data format that can be used to format between String and HL7 model objects.
To use the data format, simply instantiate an instance and invoke the marhsal or unmarshl 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. 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. Notice there is a shorthand syntax in Camel for well-known data formats that is commonly used. from("direct:hl7in").marshal().hl7().to("jms:queue:hl7out"); from("jms:queue:hl7out").unmarshal().hl7().to("patientLookupService"); Message HeadersThe unmarshal operation adds these MSH fields as headers on the Camel message: Camel 1.x
Camel 2.0
All headers are String types. If a header value is missing, its value is null. OptionsThe HL7 Data Format supports the following options:
DependenciesTo use HL7 in your camel routes you need to add a dependency on camel-hl7, which implements this data format. If you use Maven, you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hl7</artifactId> <version>1.6.0</version> </dependency> Camel 2.3: The HAPI library version 0.6 has been split into a base library and several structures libraries, one for each HL7v2 message version:
By default camel-hl7 only references the HAPI base library. Applications are responsible for including structures libraries themselves. For example, if a application works with HL7v2 message versions 2.4 and 2.5 then the following dependencies must be added:
<dependency>
<groupId>ca.uhn.hapi</groupId>
<artifactId>hapi-structures-v24</artifactId>
<version>0.6</version>
</dependency>
<dependency>
<groupId>ca.uhn.hapi</groupId>
<artifactId>hapi-structures-v25</artifactId>
<version>0.6</version>
</dependency>
OSGiWhen running camel-hl7 on an OSGi platform it is recommended to use this hapi-0.6 OSGi bundle from the Camel Maven repository. This bundle contains the HAPI base library and all structure libraries on the bundle classpath. SamplesIn the following example we send a HL7 request to a HL7 listener and retrieves a response. We use plain String types in this example: String line1 = "MSH|^~\\&|MYSENDER|MYRECEIVER|MYAPPLICATION||200612211200||QRY^A19|1234|P|2.4"; String line2 = "QRD|200612211200|R|I|GetPatient|||1^RD|0101701234|DEM||"; StringBuffer in = new StringBuffer(); in.append(line1); in.append("\n"); in.append(line2); String out = (String)template.requestBody("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec", in.toString()); In the next sample, we want to route HL7 requests from our HL7 listener to our business logic. We have our business logic in a plain POJO that we have registered in the registry as hl7service = for instance using Spring and letting the bean id = hl7service. Our business logic is a plain POJO only using the HAPI library so we have these operations defined: public class MyHL7BusinessLogic { // This is a plain POJO that has NO imports whatsoever on Apache Camel. // its a plain POJO only importing the HAPI library so we can much easier work with the HL7 format. public Message handleA19(Message msg) throws Exception { // here you can have your business logic for A19 messages assertTrue(msg instanceof QRY_A19); // just return the same dummy response return createADR19Message(); } public Message handleA01(Message msg) throws Exception { // here you can have your business logic for A01 messages assertTrue(msg instanceof ADT_A01); // just return the same dummy response return createADT01Message(); } } Then we set up the Camel routes using the RouteBuilder as follows: DataFormat hl7 = new HL7DataFormat(); // we setup or HL7 listener on port 8888 (using the hl7codec) and in sync mode so we can return a response from("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec") // we use the HL7 data format to unmarshal from HL7 stream to the HAPI Message model // this ensures that the camel message has been enriched with hl7 specific headers to // make the routing much easier (see below) .unmarshal(hl7) // using choice as the content base router .choice() // where we choose that A19 queries invoke the handleA19 method on our hl7service bean .when(header("CamelHL7TriggerEvent").isEqualTo("A19")) .beanRef("hl7service", "handleA19") .to("mock:a19") // and A01 should invoke the handleA01 method on our hl7service bean .when(header("CamelHL7TriggerEvent").isEqualTo("A01")).to("mock:a01") .beanRef("hl7service", "handleA01") .to("mock:a19") // other types should go to mock:unknown .otherwise() .to("mock:unknown") // end choice block .end() // marhsal response back .marshal(hl7); Notice that we use the HL7 DataFormat to enrich our Camel Message with the MSH fields preconfigued on the Camel Message. This lets us much more easily define our routes using the fluent builders. Sample using plain String objectsIn this sample we use plain String objects as the data format, that we send, process and receive. As the sample is part of a unit test, there is some code for assertions, but you should be able to understand what happens. First we send the plain string, Hello World, to the HL7MLLPCodec and receive the response as a plain string, Bye World. MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedBodiesReceived("Bye World"); // send plain hello world as String Object out = template.requestBody("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec", "Hello World"); assertMockEndpointsSatisfied(); // and the response is also just plain String assertEquals("Bye World", out); Here we process the incoming data as plain String and send the response also as plain String: from("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec") .process(new Processor() { public void process(Exchange exchange) throws Exception { // use plain String as message format String body = exchange.getIn().getBody(String.class); assertEquals("Hello World", body); // return the response as plain string exchange.getOut().setBody("Bye World"); } }) .to("mock:result"); See Also
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- [CONF] Apache Camel > HL7 confluence
- [CONF] Apache Camel > HL7 confluence
