Connect to HL7 File servers¶

This guide explains how to connect to HL7 file servers using the WSO2 Open Healthcare. The WSO2 Open Healthcare provides built-in capabilities to read HL7 messages from files and process them.

:::note These guides use Ballerina, a language designed for integration and network services, to build healthcare integrations as microservices. :::

Ballerina¶

The following example demonstrates how to connect to an HL7 file server using Ballerina FTP client and consume HL7 files.

Step 1: Set Up Ballerina¶

Before you begin, ensure you have Ballerina installed on your system.

Step 2: Implement the flow to connect to the HL7 file server¶

Create a Ballerina project using the following command. It will create the Ballerina project and the main.bal file can be used to implement the logic.
```
$ bal new hl7_file_client_sample
```

Import the required modules to the Ballerina program and implement the logic to connect to the HL7 file server. In this sample, we are using the HL7v2.3 version. Therefore, we need to import the ballerinax/health.hl7v23 package. If you are using a different version of HL7, you can import the relevant package. Then ADT_A01 message is read from the file Ballerina FTP client and parsed to HL7 message.

import ballerinax/health.hl7v2;
import ballerinax/health.hl7v23;
import ballerina/io;

public function main() returns error? {
    // Define the FTP client configuration.
    ftp:ClientConfiguration ftpConfig = {
        protocol: ftp:FTP,
        host: "<The FTP host>",
        port: <The FTP port>,
        auth: {
            credentials: {
                username: "<The FTP username>",
                password: "<The FTP passowrd>"
            }
        }
    };

    // Create the FTP client.
    ftp:Client ftpClient = check new(ftpConfig);

    stream<byte[], io:Error?>|Error str = ftpClient -> get("<The HL7 message file path>");
    if (str is stream<byte[], io:Error?>) {
        record {|byte[] value;|}|io:Error? arr1 = str.next();
        if (arr1 is record {|byte[] value;|}) {
            hl7v23:ADT_A01 adtMsg = check hl7:parse(arr1.value).ensureType(hl7v23:ADT_A01);
            // Access the fields of the ADT_A01 message.
            hl7v23:XPN[] patientName = adtMsg.pid.pid5;
            io:println("Family Name: ", patientName[0].xpn1);
        }
        io:Error? closeResult = str.close();
    }
}

Run the Ballerina program using the following command.
```
$ bal run
```
The program reads the ADT_A01 HL7 message from the file and prints the family name of the patient.