Electronic Data Interchange (EDI) has been around for many decades and has been replaced to a large extend by other ways of data interchange like XML (computer readable) and newer formats like JSON. Still there are EDI messages in use, perhaps in your organization. How do you turn these messages into more modern formats? With WSO2 EI of course. In this blog, we will take a dummy EDI message file and turn it into an XML file. As a second step, we store the data in a database as well. First things first. How will we process files?
We will use the VFS transport to process an EDI file (a simple plaintext file). The VFS transport comes in two flavors, the sender and receiver. Uncomment both in the [EI-HOME]/conf/axis2/axi2.xml. Keep in mind that these two are not next to each other in the axis2 file:
<transportSender name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportSender"/>
<transportReceiver name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportListener"/>
Furthermore, we will use the PlainTextBuilder, a message builder that is available in axis2 file.
<messageBuilder contentType="text/plain" class="org.apache.axis2.format.PlainTextBuilder"/>
All changes to axis2 require a restart of the WSO2 EI since these parameters are only loaded at startup.
Configuration of the VFS
As you can read in other blogs on VFS we need to configure the input directory on which we listen to a new file:
<?xml version="1.0" encoding="UTF-8"?>
The graphical overview is extremely simple, especially since parameters are not visible in the graphical mode but are in the source mode. Of course, you need to change the parameters in the proxy and local entry in order to match your setup.
Smooks is an extensible framework for building applications for processing XML and non XML data (CSV, EDI etc). The Smooks mediator allows you to do that within the Enterprise Integrator. It can be used to perform a wide range of Data Transforms - XML to XML, CSV to XML, EDI to XML, XML to EDI, XML to CSV etc.
The highlevel syntax is as follows:
<output [type="|text|xml|java"] [property="string"] [action="string"]/>
The config-key is used to access the Smooks configuration. The Smooks configuration should be saved in the Registry as a local entry before it can be used here. You can also refer to a file for the config-key. The Smooks configuration file uses a number of other technologies to make it work.
First of all, we see a number of xsd’s included like javabean, file-routing and freemarker. The data will be read one line at a time by the SAX parser.
In the EDI mapper the line is transformed according to the layout of the EDI message and subsequently put into a hashtable and using the freemarker template written to an xml file.
<!-- Configure the EDI Parser to parse the message stream into a stream of SAX events. -->
<!-- Populate java objects to message data-->
<jb:bean beanId="order" class="java.util.Hashtable" createOnElement="order">
<jb:value property="id" decoder="Integer" data="order/id"/>
<jb:value property="price" decoder="Double" data="order/price"/>
<jb:value property="quantity" decoder="Integer" data="order/quantity"/>
<jb:value property="symbol" data="order/symbol"/>
<!-- Apply freemarker templating -->
<!-- Output the templating result to the
"orderItemSplitStream" file output stream... -->
<!-- Create/open a file output stream. This is writen to by the freemarker template (above).. -->
<file:outputStream resourceName="orderItemSplitStream" openOnElement="order">
We have adapted this blog from the sample 659 included with the Enterprise Integrator. Setup an EI-6.2.0 on your machine. Do it close to the root when working on Windows due to the PATH length restriction.
I made a setup where the proxy will listen on a directory called C:\EI\wos2ei-6.2.0\smooks\ with
orders directories. As you can see, this is a Windows setup. So you will need to change the settings to match your setup. At the Yenlo Bitbucket you can find all resources needed. I’ve also changed the location of the smooks-config.659 in the Bitbucket Sample to be in the smooks subdirectoru
Open the proxy and change to the directory locations applicable to you.
- transports.vfs.FileURI- The input file location.
transports.vfs.MoveAfterProcess- The location to move the input file after it is processed.
transports.vfs.MoveAfterFailure- The location to move the input file if there happens to be a failure at the time of processing.
<[EI_HOME]/repository/sample/smooks-config-659.xml and the proxy (see below) and change to the directory locations applicable to you. It is the
file:destinationDirectoryPattern> you need to change.
The proxy uses the VFS system to listen to a directory and will take the file, parse it and write the file to the directory orders. The Name is assembled from the EDI file and the order number.
So what can we do with this?
The setup we have created can be used for other EDI messages by changing the EDI mapping to support other layouts. You now know that an EDI message can be read by the Enterprise Integrator with minimal changes. Only the VFS needs to be enabled and a plain text message builder added to the axis2.xml configuration.