code: protected void setRequestContent(HTTPRequest httpRequest,HttpMethodBase httpMethodClient)
      {
          //set content
          if(httpMethodClient instanceof EntityEnclosingMethod)
          {
              EntityEnclosingMethod pushMethod=(EntityEnclosingMethod)httpMethodClient;
              
              RequestEntity requestEntity=null;
              ContentType contentType=httpRequest.getContentType();
              switch(contentType)
              {
                  case STRING:
                      requestEntity=this.createStringRequestContent(httpRequest);
                      break;
                  case BINARY:
                      requestEntity=this.createBinaryRequestContent(httpRequest);
                      break;
                  case MULTI_PART:
                      requestEntity=this.createMultiPartRequestContent(httpRequest,httpMethodClient);
                      break;
                  default:
                      throw new FaxException("Unsupported content type: "+contentType);
              }
  
              //set request data
              if(requestEntity!=null)
              {
                  pushMethod.setRequestEntity(requestEntity);
                  pushMethod.setContentChunked(false);
              }
          }
      }
docs: This function sets the request content.
  
  @param   httpRequest
  The HTTP request
  @param   httpMethodClient
  The apache HTTP method