wso2esb - vfs-Proxy read/write binary with payloadFactory and mtom-optimization - wso2

Question

Scenario:
I have a vfs-Proxy monitoring a folder for files with the extention .pdf.
The Proxy parses the file-content in base64binary into
<axis2ns#:binary xmlns:axis2ns#="http://ws.apache.org/commons/ns/payload">JVBERi0xLjMKJfbk/N8K...</axis2ns#:binary>
# is a incremental number and as far as i know, i don't have an influence on this mater. With a payloadFactory i reformat the payload to be surrounded by
<datatype:pdf xmlns:datatype="http://mynamespace.org/payload"> instead.
Problem:
The resulting file looks like this:
--MIMEBoundary_e1f5b2321e28e0a638b52a178d5c7ee40c2f3ae08cd43818
Content-Type: application/xop+xml; charset=UTF-8; type="text/xml"
Content-Transfer-Encoding: binary
Content-ID: <0.f1f5b2321e28e0a638b52a178d5c7ee40c2f3ae08cd43818#apache.org>
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Body>
<datatype:pdf xmlns:datatype="http://mynamespace.org/payload">
JVBERi0xLjMKJfbk/N8K...
</datatype:pdf>
</soapenv:Body>
</soapenv:Envelope>
--MIMEBoundary_e1f5b2321e28e0a638b52a178d5c7ee40c2f3ae08cd43818--
instead of an actual pdf-document. What's necessary to change that? I'm pretty sure it has so be something with the content-types or the payloadFactory. Is there a way to specify which tags are treated as payload? I have already tried to a few different types, settings and searched but coudn't find a solution. If i interpret the resulting message correct mtom isn't working as it is supposed to. Shouldn't there be a
<xop:Include href="...">
inside the resulting message instead of the inline base64binary?
Simple Code for reproduction:
<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
name="VFSVFS"
transports="vfs"
statistics="disable"
trace="disable"
startOnLoad="true">
<target>
<inSequence>
<property name="OUT_ONLY" value="true"/>
<property name="enableMTOM" value="true" scope="axis2" type="STRING"/>
<property name="enableSWA" value="false" scope="axis2" type="STRING"/>
<property name="transportNonBlocking"
value="true"
scope="axis2"
action="remove"/>
<payloadFactory media-type="xml">
<format>
<datatype:pdf xmlns:datatype="http://mynamespace.org/payload">
$1
</datatype:pdf>
</format>
<args>
<arg evaluator="xml" expression="$body/*[1]"/>
</args>
</payloadFactory>
<property name="messageType" value="application/octet-stream" scope="axis2"/>
<property name="transport.vfs.ReplyFileName" expression="fn:concat(fn:substring-after(get-property('MessageID'), 'urn:uuid:'), 'abc.pdf')" scope="transport"/>
<property name="transport.vfs.Streaming" value="true" scope="transport" type="STRING"/>
<send>
<endpoint xmlns="http://ws.apache.org/ns/synapse" name="FileOut_VFS">
<address uri="vfs:file:///home/user/Development/data/testfiles/init/out" optimize="mtom" />
</endpoint>
</send>
<property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
</inSequence>
</target>
<parameter name="transport.vfs.ActionAfterProcess">DELETE</parameter>
<parameter name="transport.PollInterval">5</parameter>
<parameter name="transport.vfs.FileURI">file:///home/user/Development/data/testfiles/init/in</parameter>
<parameter name="transport.vfs.MoveAfterFailure">file:///home/user/Development/data/failure</parameter>
<parameter name="transport.vfs.Locking">false</parameter>
<parameter name="transport.vfs.FileNamePattern">.*.pdf</parameter>
<parameter name="transport.vfs.ContentType">application/octet-stream</parameter>
<parameter name="transport.vfs.ActionAfterFailure">MOVE</parameter>
<parameter name="transport.vfs.FailedRecordsFileDestination">file:///home/user/Development/data/failure</parameter>
<description/>
</proxy>
The code above is just for the purpose of simplification. The actual project performs those key operations:
read-in a pdf
aggregate the soap-message with additional information from various sources
manipulate the pdf-content with a custom mediator
write-out the new pdf
For the purpose of aggregation and manipulation i want to reformat the initial body with the payloadFactory. But as soon as I change a thing, the message no longer arrives in a fitting format.
This applies even in the simple code above.
Here a few examples of tried out combination's and their results:
<ns:binary xmlns:ns="http://ws.apache.org/commons/ns/payload">$1</ns:binary>
WITH OR WITHOUT
<property name="ContentType" value="application/octet-stream" scope="axis2"/>
RESULTS IN
INFO - AxisEngine [MessageContext: logID=6143bc348d4852f3ffa02dba72391ab0860fe7c27625f167] ContentID is null
[2015-10-16 08:19:40,923] ERROR - AsyncCallback ContentID is null
java.lang.RuntimeException: ContentID is null
EVEN WITH <property name="enableMTOM" value="false" scope="axis2" type="STRING"/>
<ns:text xmlns:ns="http://ws.apache.org/commons/ns/payload">$1</ns:text>
WITH OR WITHOUT
<property name="ContentType" value="application/octet-stream" scope="axis2"/> RESULTS IN
File with base64binary as plain/text in it -> no functioning pdf.

Answer 1

I guess, you should change the format to the following so it will be treated as text.
<format>
<ns:text xmlns:ns="http://ws.apache.org/commons/ns/payload">$1</ns:text>
</format>
Hope that helps. I guess you won't be able to open the file because it will have the wrong encoding.
Regards
Martin

Answer 2

Not sure if I get it right. If I look at the proxy it seems that you'd like to read a pdf and write it to some other location. So you just could use the following to write the file.
<send>
<endpoint>
<address uri="vfs:file:///home/user/Development/data/testfiles/init/out"/>
</endpoint>
</send>
Inside the ESB every message/file that arrives will be converted to a soap message.
Regards
Martin

Answer 3

From this post on the ws-commons-dev mailing list finally send me in the right direction.
The problem is that to make this work the OMElement object has be have a Content ID OR have the flag isBinary set to true.
This is a attribute on the OMTextImpl and from what I can tell this has to be done on the object and can not be set from the XML payload. So in the end I had to add a script mediator to do this.
<payloadFactory media-type="xml">
<format>
<ns:binary xmlns:ns="http://ws.apache.org/commons/ns/payload">$1</ns:binary>
</format>
<args>
<arg evaluator="xml" expression="$body/attachments/content"/>
</args>
</payloadFactory>
<script language="js">
<![CDATA[
var binaryNode =
mc.getEnvelope().getBody().getFirstElement().getFirstOMChild();
binaryNode.setBinary(true);
]]>
</script>
In the example above the base64 data comes in as part of the incoming message.