CICS(Customer Information Control System), a transaction system that runs
primarily on IBM mainframe.The CICS transport can be used to call mainframe
programs by sending XML messages to Mule.Mainframe programs have fixed-length
record layouts for input/output.
XML, on the other hand does not have length-restriction for an element's value.

The CICS transport provides transformers to transform messages between XML and
fixed-length format.

The typical steps (inside Mule) to send XML messages to mainframe are as
follows:

•XML messages are received by Mule from the client (e.g: a JMS queue).
•The mainframe operation to be invoked is detected from the XML message.
•The XML message is converted into a fixed-length mainframe format.
•The mainframe program is invoked via CICS.
•The fixed-length binary response is converted into XML.
•The XML response is sent back to the client (e.g: the JMS reply queue).
An example XML message received from a client is shown below:

•Request XML Message
<sample-command xmlns="http://ogis-ri.co.jp/SAMPLE-COMMAND">
<customer-info>
<customer-no></customer-no>
<customer-name>Jones</customer-name>
<customer-address>Boston</customer-address>
<date>20080401</date>
<customer-info>
</sample-command>
The XML is transformed into fixed-length format required by mainframe.

Fixed-length request message

< \+Jones \+Boston
\+20080401>
| | | | |
| | | | |
-+cust-no+-\--customer-name
\--\--+\--\-+-+customer-address+-\---------------\--\|--date-\-
A fixed-length message is received from mainframe.
Response fixed-length message

<00002+20080401+0000050001+Bill Jones +1024, Parker Road, Boston, USA
\+006000+0000060001+Matt Jones
\+101, Miller Road, Boston, USA \+001000+>
The fixed-length message is transformed into XML as shown below.

Response XML Message

<sample-response xmlns="http://ogis-ri.co.jp/SAMPLE-RESPONSE">
<no-of-records>2</no-of-records>
<date>20080401</date>
<customer-list>
<customer-no>0000050001</customer-no>
<customer-name>Bill Jones</customer-name>
<customer-address>1024, Parker Road, Boston,USA</customer-address>
<customer-charge>6000</customer-charge>
</customer-list>
<customer-list>
<customer-no>0000060001</customer-no>
<customer-name>Matt Jones</customer-name>
<customer-address>101, Miller Road, Boston,USA</customer-address>
<customer-charge>1000</customer-charge>
</customer-list>
</sample-response