POST or PUT method need content-length in request header field.
Does another method(GET, PATCH, DELETE, OPTIONS, CONNECT, TRACE, HEADER) also need content-length?
About content-length in Response, specification is described in rfc2616.
The Content-Length entity-header field indicates the size of the entity-body, in decimal number of OCTETs, sent to the recipient or, in the case of the HEAD method, the size of the entity-body that would have been sent had the request been a GET.
Althought, I couldn't find specification about request header..