Java Mapping : Base64 Zipped CSV to XML Conversion

Introduction

In my recent client project i had a requirement where the incoming file was a csv file zipped and Base64 encoded. Source system was Ariba and Target was ECC.

My aim at writing this blog is to provide you with a reusable Java Mapping for similar requirements.

Description

Ariba sends file to PI using webservice. The encoded file is within a tag named “Header”.

Following actions are required to be performed by PI before sending the file to ECC for further processing .

1. Decode base64 file

2. Unzip the content

3. Convert the unzipped CSV file into XML

In order to achive the above i have created a Java Mapping.

Incoming Payload

Encoded file is is within the “HeaderExport” Tag

CSV file after unzipping

Source Code : Please see attachment.

Output of the Mapping

package com.map;

import java.io.ByteArrayInputStream;
import java.lang.Object;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.w3c.dom.Element;
import javax.xml.bind.DatatypeConverter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;

import au.com.bytecode.opencsv.CSVReader;

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;


//csv start
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Map;
import java.util.Properties;
import java.util.StringTokenizer;

import com.sap.aii.mapping.api.AbstractTrace;
import com.sap.aii.mapping.api.DynamicConfiguration;
import com.sap.aii.mapping.api.DynamicConfigurationKey;
import com.sap.aii.mapping.api.StreamTransformation;
import com.sap.aii.mapping.api.StreamTransformationConstants;
import com.sap.aii.mapping.api.StreamTransformationException;

import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

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;


//csv end

public class Base64DecodeAndUnzip extends AbstractTransformation {
	@SuppressWarnings("null")
	@Override
	public void transform(TransformationInput input, TransformationOutput output) throws
	StreamTransformationException {
		try {
			// Get base64 string from DOM input
			InputStream is = input.getInputPayload().getInputStream();
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document docIn = builder.parse(is);
			NodeList details = docIn.getElementsByTagName("HeaderExportFile");
			String b64 = details.item(0).getFirstChild().getNodeValue();
			//First decode the base 64 string
			byte[] decoded = DatatypeConverter.parseBase64Binary(b64);
			//Next, unzip the file (assumption only 1 entry in zip file)
			ZipInputStream zis = new ZipInputStream(new ByteArrayInputStream(decoded));
			ByteArrayOutputStream baos = new ByteArrayOutputStream();




			ZipEntry ze = zis.getNextEntry();
			if (ze != null) {
				byte[] buffer = new byte[1024];
				int read = 0;
				while ((read = zis.read(buffer, 0, buffer.length)) != -1) {
					baos.write(buffer, 0, read);
				}
				baos.flush();
				zis.closeEntry();
			}
			zis.close();


			//			//csvstart
			BufferedReader br = null;
			int rowsCount = -1;
			String line = "";
			String cvsSplitBy = ",";
			String result = "";
			String fresult = "";
			String[] records = null;
			String[] csvFields = null;
			int fieldCount = 0;
			InputStream inputStream = new ByteArrayInputStream(baos.toByteArray());
			String startElement =  "ContractId";
			DocumentBuilderFactory domFactory = null;
			DocumentBuilder domBuilder = null;
			StringTokenizer stringTokenizer = null;

			domFactory = DocumentBuilderFactory.newInstance();
			domBuilder = domFactory.newDocumentBuilder();


			Document newDoc = domBuilder.newDocument();
			Element rootElement = newDoc.createElement("Record");
			newDoc.appendChild(rootElement);
            

         
			br = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));

//			CSVReader readerCsv = new CSVReader(br, cvsSplitBy.charAt(0));
			
			if ((line = br.readLine()) != null)
			{

				//records = line.split(cvsSplitBy);
				stringTokenizer = new StringTokenizer(line, cvsSplitBy, false);
				
				if (stringTokenizer.countTokens() > 0 )
					while (stringTokenizer.hasMoreElements()){
						int i = 0 ;
						try{  

							result = stringTokenizer.nextElement().toString();
							i++;
						}
						catch(Exception e){
						}	
						break;
					}


			}

			if ((line = br.readLine()) != null)
			{

				//records = line.split(cvsSplitBy);
				stringTokenizer = new StringTokenizer(line, cvsSplitBy);
				if (stringTokenizer.countTokens() > 0 )
					csvFields = new String[stringTokenizer.countTokens()];
				int i = 0 ;
				while (stringTokenizer.hasMoreElements()){


					csvFields[i++] = String.valueOf(stringTokenizer.nextElement()).replaceAll(" ","" );

				}

			}

			// At this point the coulmns are known, now read data by lines
			while ((line = br.readLine()) != null) {
				stringTokenizer = new StringTokenizer(line, cvsSplitBy);
				fieldCount = stringTokenizer.countTokens();
				if (fieldCount > 0) {
					Element rowElement =  newDoc.createElement("row");
					int i = 0;
					while (stringTokenizer.hasMoreElements()) {
						try {
							String curValue = String.valueOf(stringTokenizer.nextElement()).replaceAll("\"","");
							
							Element curElement = newDoc.createElement(csvFields[i++]);
							
							curElement.appendChild(newDoc.createTextNode(curValue));
							rowElement.appendChild(curElement);
						} catch (Exception exp) {
						}
					}
					rootElement.appendChild(rowElement);
					rowsCount++;
				}
			}
			br.close();

			Transformer transformer = TransformerFactory.newInstance().newTransformer();
			Source source = new DOMSource(newDoc);
			Result outpayload = new StreamResult(output.getOutputPayload().getOutputStream());
			transformer.transform(source,outpayload);
			
		} catch (Exception e) {
			throw new StreamTransformationException("Exception: " + e.getMessage(), e);
		}
	}
}