MLLP component

Q: How do I send my own acknowledgement?

Set the header CamelMllpAcknowledgementString (or CamelMllpAcknowledgement as bytes) in the route. To only change the code, set CamelMllpAcknowledgementType to AE or AR.

Q: How do I read HL7 fields?

Use the hl7terser language with a terser path, for example a setHeader step whose expression is hl7terser: PID-5-1 (the patient's family name). The hl7 data format parses the whole message.

The mllp component sends and receives HL7 v2 healthcare messages over TCP with MLLP framing, and generates HL7 acknowledgements automatically.

Scheme: mllp: · Crate: cameleer-protocols · Cargo feature: protocols · Consumer: yes · Producer: yes · Apache Camel: MLLP

When to use it

Build an HL7 interface engine: receive ADT, ORM or ORU messages from a hospital system and forward them.
Run a small HL7 gateway next to lab devices or in a clinic (edge), forwarding messages to Kafka or HTTP.
Send HL7 messages to a remote system and check its acknowledgement (AA, AE, AR).

URI format

text

mllp://host:port[?options]

A consumer listens on host:port (0.0.0.0 for all interfaces); a producer connects to it.

Example

yaml example: mllp-hl7-gateway

- route:
    id: hl7-inbound
    from:
      uri: mllp://0.0.0.0:{{env:MLLP_PORT:2575}}
      steps:
        - log: "HL7 ${header.CamelMllpMessageType} from ${header.CamelMllpSendingApplication}, control id ${header.CamelMllpMessageControlId}"
        - to: log:hl7

Each message is answered with MSA|AA|<control id> when the route succeeds and MSA|AE|... when it fails. Send a test message with another route: to: mllp://localhost:2575.

Rust DSL

rust

use cameleer_core::prelude::*;

pub fn routes(ctx: &CamelContext) -> Result<()> {
    ctx.add_routes(|b| {
        b.from("mllp://0.0.0.0:2575")
            .route_id("hl7-inbound")
            .log("HL7 ${header.CamelMllpMessageType} from ${header.CamelMllpSendingApplication}, control id ${header.CamelMllpMessageControlId}")
            .to("log:hl7");
    })
}

Options

option	default	description
`autoAck`	`true`	Consumer: generate the HL7 acknowledgement.
`hl7Headers`	`true`	Consumer: set the `CamelMllp*` headers from the `MSH` segment.
`stringPayload`	`true`	Body as a string; `false` gives bytes.
`validatePayload`	`false`	Check the HL7 structure of received messages.
`charsetName`	`UTF-8`	`UTF-8` or `ISO-8859-1`.
`receiveTimeout`	`15000`	Producer: how long (ms) to wait for the acknowledgement.
`readTimeout`	`5000`	How long (ms) to wait for the rest of a started frame.
`connectTimeout`	`30000`	Producer: connect timeout (ms).
`idleTimeout`	`0`	Consumer: close idle connections after this many ms. `0` never closes.
`keepAlive`	`true`	TCP keep-alive.
`tcpNoDelay`	`true`	Disable Nagle's algorithm.
`maxBufferSize`	1 GiB	Largest accepted frame.
`sslContextParameters`		`#bean`: the consumer accepts TLS (needs key material) and the producer connects with TLS.
`useGlobalSslContextParameters`	`false`	Use the global `camel.ssl.*` parameters for TLS.

Message headers

header	direction	description
`CamelMllpSendingApplication`, `CamelMllpSendingFacility`, `CamelMllpReceivingApplication`, `CamelMllpReceivingFacility`	out (consumer)	From `MSH-3` to `MSH-6`.
`CamelMllpTimestamp`, `CamelMllpSecurity`, `CamelMllpMessageType`, `CamelMllpEventType`, `CamelMllpTriggerEvent`, `CamelMllpMessageControlId`, `CamelMllpProcessingId`, `CamelMllpVersionId`	out (consumer)	From the other `MSH` fields.
`CamelMllpCharset`	out (consumer)	The character set.
`CamelMllpLocalAddress`, `CamelMllpRemoteAddress`	out	Socket addresses.
`CamelMllpAcknowledgement` / `CamelMllpAcknowledgementString`	in (consumer), out (producer)	The acknowledgement as bytes / string. A route can set it to send its own.
`CamelMllpAcknowledgementType`	in (consumer), out (producer)	`AA`, `AE`, `AR` (or `CA`, `CE`, `CR`). A route can set it to force the code.

A producer that receives AE / AR fails with MllpApplicationErrorAcknowledgementException / MllpApplicationRejectAcknowledgementException; no acknowledgement gives MllpAcknowledgementTimeoutException.

Run it with Docker

docker run --rm -p 2575:2575 -v "$PWD:/routes:ro" pmsudhi/cameleer run /routes/hl7.camel.yaml

Common questions

How do I send my own acknowledgement?

Set the header CamelMllpAcknowledgementString (or CamelMllpAcknowledgement as bytes) in the route. To only change the code, set CamelMllpAcknowledgementType to AE or AR.

How do I read HL7 fields?

Use the hl7terser language with a terser path, for example a setHeader step whose expression is hl7terser: PID-5-1 (the patient's family name). The hl7 data format parses the whole message.

Is the connection kept open?

Yes. The producer reuses its connection between messages.

Found a problem?

If something on this page doesn't match what Cameleer does, or you hit a bug while building with it, please help fix it, whether you are a person or a coding agent: open an issue that describes what you saw, then fork the repository, fix it, add or update a test, run cargo test --workspace, and open a pull request. CONTRIBUTING.md explains the ground rules.