How to pass a file to a web service.

What would be the web service equivalent of this HTTP request?

wsTest.cfm

<cfhttp url="https://secure-devsite/pur-loader/ws/ppur_v0.cfc" method="post" multipart="yes">
     <cfhttpparam name="authentication" value="xxxxxxxxxxxxxxxx" type="formfield">
     <cfhttpparam name="ppurfile" file="#expandPath('ppur-test.xml')#" type="file">
     <cfhttpparam name="method" value="dataSubmit" type="url">
</cfhttp>
<cfoutput>#htmlEditFormat(cfhttp.FileContent)#</cfoutput>

ppur_v0.cfc

<cffunction name="dataSubmit" access="remote" output="no" returntype="xml">
     <cfargument name="authentication" type="string" required="yes" hint="authentication value">
     <cfargument name="ppurFile" type="string" required="yes" hint="file upload field">
        <cfset var dataResult = "">
     <cfset var rootpath = getDirectoryFromPath(getCurrentTemplatePath())>

     <cfset path = replace(rootpath,"htdocs/pur-loader/ws/","uploadedFiles/ppur/","ONE")>

     <cffile action="upload" filefield="ppurFile" destination="#path#" nameconflict="overwrite">
          
     <cfset var validate = xmlValidate(cffile.serverDirectory & '/' & cffile.serverFile,replace(rootpath,'/ws/','/schema/ppur-data-transmission.xsd','ONE'))>
...
</cffunction>

I.E.  How would one pass a 'file' to a web service?  Or can you only pass the content of the file as a string?  Which is differernt and apparently does not work for what we are trying to do.  When I did that, we would start getting 'java heap out of memory' errors dealing with the quanty of content we need to pass to this web service.

To clarify, is there a way to pass a file reference through a web service object that can be used in a <cffile action="upload"...> tag in the <cffunction...> block?