Adding Attachments to Emails in SAP CPI Using Groovy

In the world of integration, sending emails with attachments is a common requirement. For SAP Cloud Platform Integration (CPI) developers, using Groovy scripts can streamline this process, ensuring that files are sent without corruption. In this blog, we will explore how to convert a message body to a Base64 format and use it as an attachment in an email, all while avoiding common pitfalls that can lead to file corruption.

The Complete Groovy Script

Here’s the complete Groovy script that we will dissect:

import com.sap.gateway.ip.core.customdev.util.Message

import org.apache.camel.impl.DefaultAttachment

import javax.mail.util.ByteArrayDataSource

def Message processData(Message message) {

    def body = message.getBody(java.lang.String) as String;

    

    // 1: Get the binary attachment content in the form of a byte array

    def pdfBytes = body.decodeBase64()

    

    // 2: Construct a ByteArrayDataSource object with the byte array and the content's MIME type

    def data = new ByteArrayDataSource(pdfBytes, 'application/pdf')

    

    // 3: Construct a DefaultAttachment object

    def att = new DefaultAttachment(data)

    

    // 4: Add the attachment to the message

    message.addAttachmentObject('SamplePdf.pdf', att)

    

    return message

}

 

Step-by-Step Explanation

Step 1: Import Necessary Classes

import com.sap.gateway.ip.core.customdev.util.Message

import org.apache.camel.impl.DefaultAttachment

import javax.mail.util.ByteArrayDataSource

In this initial step, we import the necessary classes. The Message class is crucial for handling the message content, while DefaultAttachment and ByteArrayDataSource are used to create and manage the email attachment.

Step 2: Retrieve the Message Body

 

def Message processData(Message message) {

def body = message.getBody(java.lang.String) as String;

 

Here, we define the processData method, which is the entry point for our Groovy script. It takes a Message object as a parameter, allowing us to manipulate the message's content and attachments. In the next line we retrieve the body of the message, which is expected to be in Base64 format. This is done by calling getBody on the message object and casting it to a String.

Step 3: Decode the Base64 Content

 

def pdfBytes = body.decodeBase64()

 

In this step, we decode the Base64-encoded string into a byte array. This is crucial because attachments need to be in binary format, and decoding ensures that we have the correct byte representation of the file.

Step 4: Create a ByteArrayDataSource

 

def data = new ByteArrayDataSource(pdfBytes, 'application/pdf')

We create a ByteArrayDataSource object, which takes the byte array and the MIME type of the content (in this case, application/pdf). This object acts as a bridge between the byte data and the email attachment.

Step 5: Construct the Attachment and add attachment to the message

 

def att = new DefaultAttachment(data)

message.addAttachmentObject('SamplePdf.pdf', att)

 

Here, we construct a DefaultAttachment object using the ByteArrayDataSource. This object encapsulates the attachment data and is ready to be added to the email. Finally, we add the attachment to the message using addAttachmentObject. We specify the name of the file as it will appear in the email (SamplePdf.pdf) and pass the attachment object.

Conclusion

Using Groovy scripts in SAP CPI to add attachments to emails can significantly enhance the functionality of your integration flows. By following the steps outlined in this blog, you can ensure that files are sent without corruption, providing a seamless experience for end-users. Whether you are sending reports, invoices, or any other documents, this method will help you achieve your goals efficiently.