Bug reading csv per http request (WebService)

I'm having trouble reading a csv file through http request. It would be a RESTFul webService that receives a csv and uses its content. I have already tried to read it in different ways, with opencsv, JavaCsv .. Anyway, the bug I'm having is that simply passing the file by http request the readers do not recognize the '\ n' line break and the file ends up getting as if it were a single line. In all of these ways I have tried to set the 'delimiter', '' and the '\' 'line break to' hand ', without success. Sometimes I succeeded by passing csv as Base64 and then converting it into the service, but I would not want my client to need to convert the file before sending. Another way was to change the '\ n' line break to ';', but this is already out of the norm and the client would have a lot of work to do. If someone has already gone through this before, please share your experience. Thank you in advance!