In a case when there is SOAP based backend services with REST front-end interface.
REST/SOAP messages with file attachments are classified as multipart messages via the content-type header and custom java callout policies have to be written to handle these types of messages. ExtractVariables policy will work only for a xml/json message.
@Rampradeep Krishnamurthyis there a sample jar file with source that we can share with the community? Is javacallout the only way to do it? Can this be done using javascript?