This article provides a sample Java mapping code to decode Base64 string in SAP PI/PO. You can decode Base64 string in SAP PI/PO with User-Defined Function (UDF), Java Mapping and Adapter Modules. In this example, we will discuss how to achieve Base64 conversion using Java Mapping. Feel free to read my previous article on Base64 encoding and decoding methods in SAP ABAP. Additionally, you can refer to my SAP blog on the same subject.

Moreover, I have implemented an example interface with a Base64 encoding java mapping.

Additionally, we will look at how to decode a Base64 string in CI in SAP Integration Suite (CPI).

SAP Versions used in the illustration:

• SAP PO 7.5
• SAP Integration Suite CI (CPI)

Base64 Decoding Example Scenario:

Let’s assume, a sender message contains Base64 string and we need to assign the decoded string to the target message.

Source message xml node <Base64EncodedString> contains the encoded message. Decoded string should be mapped to node <Base64DecodedString> of the target message.

This example will be implemented in an SAP Process Integration (PI) system version 7.50 single stack and SAP Integration Suite CI (CPI).

Expected Functionality of Java Mapping:

Final result with input message and desired output message are as below.

The first function of Java Mapping is to convert Base64 encoded string in ‘Base64EncodedString’.

Encoded string ‘U0FQSW50ZWdyYXRpb25IdWIuY29t’ translates to ‘SAPIntegrationHub.com’.

Next, Java Mapping should form the output or target xml message.

Input Message:

<?xml version="1.0" encoding="UTF-8"?>
<ns0:Base64EncodedString xmlns:ns0="urn:Source_System:Base64EncodedString">
   <Base64EncodedString>U0FQSW50ZWdyYXRpb25IdWIuY29t</Base64EncodedString>
</ns0:Base64EncodedString>

 

Output Message:

<?xml version="1.0" encoding="UTF-8"?>
<ns1:Base64DecodedString xmlns:ns1="urn:Target_System:DecodedString">
   <Base64DecodedString>SAPIntegrationHub.com</Base64DecodedString>
</ns1:Base64DecodedString>

 

---

Steps to Implement Base64 Message Mapping in Enterprise Service Repository:

1. Create Data Types, Message Types, and Service Interfaces.
2. Create Base64 Java Mapping in Netweaver Development Studio (NWDS).
3. Implement Operation Mapping (OM).

Step 1: Create Data Types, Message Types and Service Interfaces.

Create these ESR objects to match the scenario. We have two Data types and two Message types each for sender and receiver.

Data types and Message types are defined to reflect the input and output xmls mentioned above.

Sender Data Type and Message Type:

Receiver Data Type and Message Type:

In this example we’ll use one outbound service interface for sender and one inbound service interface for receiver.

Outbound Service Interface:

Inbound Service Interface:

Step 2: Create Base64 Decoding Java Mapping in NWDS.

If you have not created Java Mappings in NWDS before, read my article on how to implement Java Mappings.

Implement the code snippet and export it as a .jar. Then import the .jar file as an Imported Archive to ESR.

package base64Decode;



import java.io.InputStream;
import java.io.OutputStream;
import com.sap.aii.mapping.api.AbstractTransformation;
import com.sap.aii.mapping.api.StreamTransformationException;
import com.sap.aii.mapping.api.TransformationInput;
import com.sap.aii.mapping.api.TransformationOutput;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;

import java.util.Base64;



public class Decoder extends AbstractTransformation {

	@Override
	
	
	
	public void transform(TransformationInput in, TransformationOutput out) throws StreamTransformationException {
	
		String encodedString = null;
		Node encodedStringNode;
		
	try	{
	
//Read input and output payloads.
		InputStream inputStream = in.getInputPayload().getInputStream();
		OutputStream outputStream = out.getOutputPayload().getOutputStream();	

//Creates new instance of DOM tree builder factory
		 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  
		 
//Creates new instance to obtain DOM document from xml.
         DocumentBuilder builder = factory.newDocumentBuilder();

//Obtain new DOM document from inputStream xml.
         Document doc = builder.parse(inputStream); 
         
//Obtain the XML node 'Base64EncodedString' of source message.
         encodedStringNode = doc.getElementsByTagName("Base64EncodedString").item(0);
         
//Get the base64 string value of the xml element 'Base64EncodedString' from source message.     
         encodedString = encodedStringNode.getFirstChild().getNodeValue();
         
//Decode base64 string to text.
         byte[] decodedBytes = Base64.getDecoder().decode(encodedString);
         String decodedString = new String(decodedBytes);
         
//Derive output(target) xml message.
         outputStream.write(("<?xml version=\"1.0\" encoding=\"UTF-8\"?><ns1:Base64DecodedString xmlns:ns1=\"urn:Target_System:DecodedString\"><Base64DecodedString>"+decodedString+"</Base64DecodedString></ns1:Base64DecodedString>").getBytes());
         
	
	} catch (Exception exception) {
		 getTrace().addDebugMessage(exception.getMessage());
		 throw new StreamTransformationException(exception.toString());
	 }
		
}
}

Step 3: Create Imported Archive and Operation Mapping (OM).

Create Imported Archive by uploading Java Mapping class defined in step 2 as a .jar to ESR. Then configure the Operation Mapping with the Imported Archive.

Test Base64 Decoding Java Mapping:

You can test Java Mapping using Operation Mapping test tool in ESR.

Base64 encoded string is ‘VGVzdGluZyBkZWNvZGVyLg==’.

---

How to Decode a Base64 String in SAP Integration Suite CI (CPI)

Let’s look at how to build an iFlow that decodes a Base64 string from an incoming XML and sends the decoded value back as the response.

Step 1 – Create a New Artifact and Define the HTTPS Address

Step 2 – Configure a Content Modifier to Extract Base64 String from XML

Using a content modifier and an XPath expression, we will extract the Base64 string from the incoming message. We will assign the extracted Base64 string from the XML to an exchange property parameter. Here, we must ensure that the incoming payload is in XML format; otherwise, the interface processing will terminate with an error.

Step 3 – Define the Message Payload with Base64 String

Now let’s write a simple expression to write the Base64 string in the exchange property parameter to the message payload. Since the Base64 decoder in CPI decodes the entire payload of the message, we need to prepare the payload or the body of the message to contain the Base64 string.

Step 4 – Add a Base64 Decoder from Transformation Options

The next step is to add a Base64 decoder from the transformation options under encoders and decoders. The Base64 decoder will simply decode the body of the incoming message.

Step 4 – Deploy and Test the iFlow

Send the Base64 string embedded in the XML and you will be able to view the decoded string in the body of the response message.

---

Hopefully, you will be able to reuse the structure of this Base64 decoding Java Mapping class for integration scenarios. Please, leave a comment below if you have any questions about Base64 decoding or Java Mappings.