Creating CSV Files from a Proxy Service

If you want to write a CSV file from a proxy service in WSO2 ESB, then following sample would help you to understand how it works.

1. Uncomment the following lines in wso2esb-4.x.x/repository/conf/axis2/axis2.xml.

   <transportreceiver class="org.apache.synapse.transport.vfs.VFSTransportListener" name="vfs"/>

   <transportsender class="org.apache.synapse.transport.vfs.VFSTransportSender" name="vfs"/>

2. Add below content into the resource called /_system/governance/xml2csv.xslt

   <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   <xsl:output method="text" encoding="iso-8859-1"/>
   
   <xsl:strip-space elements="*" />
   
   <xsl:template match="/*/child::*">
    <xsl:for-each select="child::*">
     <xsl:if test="position() != last()"><xsl:value-of select="normalize-space(.)"/>,</xsl:if>
     <xsl:if test="position()  = last()"><xsl:value-of select="normalize-space(.)"/><xsl:text>
   </xsl:text></xsl:if>
    </xsl:for-each>
   </xsl:template>
   
   </xsl:stylesheet>
   

3. Create a proxy service named CSVProxy with the following content.

   <proxy xmlns="http://ws.apache.org/ns/synapse" name="CSVProxy" transports="https,http" 
       statistics="disable" trace="disable" startOnLoad="true">
      <target>
         <inSequence>
            <property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
            <payloadFactory>
               <format>
                  <data>
                     <row>
                        <firstName>Ruchira</firstName>
                        <lastName>Wageesha</lastName>
                     </row>
                     <row>
                        <month>May</month>
                        <date>31</date>
                        <year>1984</year>
                     </row>
                     <row>
                        <street>Flower Road</street>
                        <province>Western</province>
                        <city>Colombo</city>
                        <country>Sri Lanka</country>
                        <postalCode>0007</postalCode>
                     </row>
                  </data>
               </format>
            </payloadFactory>
            <xslt key="gov:/xml2csv.xslt"/>
            <property name="transport.vfs.ReplyFileName" expression="fn:concat(fn:substring-after(get-property('MessageID'), 'urn:uuid:'), '.csv')" scope="transport"/>
            <property name="OUT_ONLY" value="true"/>
            <send>
               <endpoint>
                  <address uri="vfs:file:///home/ruchira/csv"/>
               </endpoint>
            </send>
            <drop/>
         </inSequence>
      </target>
   </proxy>                               
   

   Note : vfs:file:///home/ruchira/csv is the path where generated csv files are stored. Hence replace it with a valid path in your machine.
4. Invoke the CSVProxy service by issuing an HTTP GET to http://localhost:8280/services/CSVProxy
5. CSV files will be created in the above specified path.