Receiving AS2 Messages and Sending Back MDNs

These examples show how to use Anypoint Connector for AS2 (AS2 Connector) to receive AS2 messages from a trading partner and send MDNs (Message Disposition Notifications) to that partner in response:

Receiving AS2 Messages

Receive AS2 messages from your partner and, for every received message, log a message that contains the message payload to the Studio console.
Sending Synchronous AS2 MDNs

Send a synchronous AS2 MDN in response to each received AS2 message.
Sending Asynchronous AS2 MDNs

Send an asynchronous AS2 MDN in response to each received AS2 message.

Receiving AS2 Messages

Creating this example involves creating a new Mule project and configuring the As 2 Listener source and Logger component.

The following screenshot shows the Anypoint Studio app flow for this example:

Create a Flow to Receive the Message

Configure the AS 2 Listener source to initiate a Mule flow when a call is made to the /as2-receive path on local host port 8081:

In Anypoint Studio, create a new Mule project.
In the Mule Palette view, select the As 2 listener source and drag it to the canvas.
On the As 2 listener properties screen, optionally change the value of the Display Name field.
Set the Path field to /as2-receive.
Click the plus sign (+) next to the Connector configuration field to configure a global element that can be used by all instances of the As 2 listener source in the app.
On the General tab, click the plus sign (+) next to the HTTP Listener field.
Accept the defaults and click OK.
On the General tab, configure the keystore that contains the certificates and keys:

Field Value

Keystore Password

test

Keystore Path

as2/partnera.p12

Private Key Password

test
On the Partners tab, specify the self and partner credentials.

For the self credentials, configure these fields:

Field Value

AS2 Partner Name

partnera

x509 Alias

partnera

email

support@partnera.com

For the partner credentials, configure these fields:

Field Value

AS2 Partner Name

partnerb

x509 Alias

partnerb

email

support@partnerb.com

Field	Value
Keystore Password	`test`
Keystore Path	`as2/partnera.p12`
Private Key Password	`test`

Field	Value
AS2 Partner Name	`partnera`
x509 Alias	`partnera`
email	`support@partnera.com`

Field	Value
AS2 Partner Name	`partnerb`
x509 Alias	`partnerb`
email	`support@partnerb.com`

Add the Logger Component

Add the Logger component to the flow and configure it to log a message that includes the payload of the received message:

From the Mule Palette view, select Core and drag the Logger component next to As 2 listener.
In the Logger properties screen, set the Message field to Message Received: #[payload].

Save and Test the Mule App

Save the project.
Run the app by clicking the project name in Package Explorer and then clicking Run > Run As > Mule Application.

If the application starts correctly, the console displays this message:

Mule is up and kicking
Test the app by opening http://localhost:8081/as2-receive from a browser or an app like Postman and adding the required credentials.

For each new request, the Studio console displays the received message. For example:

INFO  2022-09-09 17:15:46,409 [[MuleRuntime].uber.06: [as2-basic-example].AS2Listener.CPU_LITE @1369de96] [processor:
AS2Listener/processors/0; event: 30609f70-307c-11ed-8f5a-38f9d3713331] org.mule.runtime.core.internal.processor.
LoggerMessageProcessor: Message Received: Test Message

XML for the Receiving AS2 Messages Example

Paste this code into your Studio XML editor to quickly load the flow for this example into your Mule app:

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:http="http://www.mulesoft.org/schema/mule/http"
	xmlns:as2-mule4="http://www.mulesoft.org/schema/mule/as2-mule4" xmlns="http://www.mulesoft.org/schema/mule/core"
	xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/as2-mule4 http://www.mulesoft.org/schema/mule/as2-mule4/current/mule-as2-mule4.xsd">
	<http:listener-config name="HTTP_Server_Config" doc:name="HTTP Listener config" >
		<http:listener-connection host="0.0.0.0" port="8081" />
	</http:listener-config>
	<as2-mule4:listener-config name="AS2_Server_Listener" doc:name="AS2 Connector Listener config" httpListenerConfig="HTTP_Server_Config" securityLevel="SIGNED_ENCRYPTED">
		<as2-mule4:self-config as2Name="partnera" x509Alias="partnera" email="support@partnera.com"/>
		<as2-mule4:partner-config as2Name="partnerb" x509Alias="partnerb" email="support@partnerb.com" />
		<as2-mule4:key-store-config keystorePassword="test" keystorePath="as2/partnera.p12" privateKeyPassword="test" />
	</as2-mule4:listener-config>
	<flow name="AS2Listener" >
		<as2-mule4:as2-listener doc:name="As 2 listener" config-ref="AS2_Server_Listener" path="/as2-receive"/>
		<logger level="INFO" doc:name="Message Received!" message="Message Received: #[payload]"/>
	</flow>
</mule>

Sending Synchronous AS2 MDNs

When your trading partner uses an AS2 listener, like in the Receiving AS2 Messages example, the listener’s MDN mode controls when a synchronous MDN is returned. The AS2 listener supports these configurations for managing synchronous MDN delivery timing:

Immediate

The listener returns the MDN as soon as the incoming message is parsed and validated. The receiver’s business flow continues as a separate process after the MDN is sent. This is the default MDN Mode.
Auto

The listener returns the MDN only after its internal business flow completes. This ensures that if the flow fails, a negative MDN is returned to the sender to signal a processing error.

For this configuration, set the MDN mode to AUTO on the AS2 listener.

		<as2-mule4:as2-listener doc:name="As 2 listener" config-ref="AS2_Server_Listener" path="/as2-receive" mdnMode="AUTO"/>

Sending Asynchronous AS2 MDNs

The AS2 listener validates the presence of the Disposition-Notification-To and Receipt-Delivery-Option headers when receiving an asynchronous MDN request. The listener immediately returns an HTTP 200 OK to acknowledge the inbound message. The listener uses the URL in the Receipt-Delivery-Option header to return the MDN via a new HTTP connection.

The AS2 listener supports these configurations for managing asynchronous MDN delivery timing:

Immediate

The listener posts the MDN to the Receipt-Delivery-Option URL as soon as the inbound message is parsed and validated. This is the default MDN Mode.
Auto

The listener posts the MDN to the Receipt-Delivery-Option URL only after its business flow completes, allowing a negative MDN to be sent if the flow fails.

For this configuration, set the MDN mode to AUTO on the AS2 listener.

		<as2-mule4:as2-listener doc:name="As 2 listener" config-ref="AS2_Server_Listener" path="/as2-receive" mdnMode="AUTO"/>