Simple-HL7v2

A simple Java HL7v2 parsing and encoding library.

HAPI HL7 v2 is excellent and comprehensive, but it's a big library (36 MB distribution tarball, 131 MB Javadoc ZIP), handling many aspects of HL7 connectivity, both as client and server. It's built from the official HL7 databases, and actually understands the structure of various version of HL7 messages.

Simple-HL7v2 on the other hand deals only with parsing, manipulating, and encoding HL7-formatted data. You need to refer to the MSH message-type field components as MSH.9.1 and MSH.9.2 rather than (with HAPI) MSH.getMessageType(), and Simple-HL7v2 will happily allow you to add fifteen components to the QRD.4 field if you tell it to.

But Simple-HL7v2 is a single 18K .jar with a dependency only on Commons-Lang3, and if you have a clear idea of the type of messages you'll be receiving and sending, and handle your own file or network transport, it may be all you need.

Download

Download JARs and source from the GitHub releases page.

Building & Requirements

Simple-HL7v2 works with JDK version 7+.

You'll need Apache Commons Lang 3 in your classpath to use the library. An older version (3.4, compatible with Java 7) is in the lib directory of the source tree.

To build a binary JAR, run

ant artifact.dist

in the root of the source tree.

To generate Javadocs, run the scripts\make-javadoc.bat batch file (or the equivalent javadoc command if you're on MacOS/Linux/etc).

Usage

For example code, see examples/SimpleHL7v2Examples.java but basic usage is quite easy:

HL7Parser parser = new HL7Parser();
Message m = parser.parse(hl7text);

String type = m.getMessageType();  // ex. "MDM^T02"

String observationTimestamp1 = m.getField("OBR.7");  // Get a field value
String observationTimestamp2 = m.getField("OBR(2).7");  // Get a field value from a repeated segment

m.setField("OBR(1).8", observationTimestamp2);  // Change a field value

HL7Encoder encoder = new HL7Encoder();
String updatedHL7text = encoder.encode(m);

Programmatic construction of segment values is made more efficient by static helper methods like indexed() and composite() in the Segment.FieldValue class.

Segment PID = new Segment("PID");
PID.addFieldValue(2,
	indexed(
		1, "0493575",
		4, composite("Big", null, "Elephant"),
		5, "ID 1")
);
PID.addFieldValue(3, "454721");
PID.addFieldValue(5, composite("DOE", "JOHN"));

Message m = new Message();
m.putSegment(PID);

Javadoc

Javadocs are available at https://jessepav.github.io/simple-hl7v2/javadoc/.