Question

I wanted to try the example code given in the CFNetwork programming guide under sub-section ‘Communicating with HTTP servers’. I tried the same example code, but the problem is it just opens the stream it does not send the http request. The exact code which I wrote in my application is as below. According to the documentation when I call the CFReadStreamOpen function it serializes and sends the http request. But when I see the packets in the wireshark. I can see just three TCP packets which are actually packlets of TCP connection three way handshake. So what’s the problem????

CFStringRef bodyData = CFSTR("mydata is here"); // Usually used for POST data

CFStringRef headerFieldName = CFSTR("X-My-Favorite-Field");
CFStringRef headerFieldValue = CFSTR("Dreams");

CFStringRef url = CFSTR("http://www.darshan.com");
CFURLRef myURL = CFURLCreateWithString(kCFAllocatorDefault, url, NULL);

CFStringRef requestMethod = CFSTR("POST");
CFHTTPMessageRef myRequest =
    CFHTTPMessageCreateRequest(kCFAllocatorDefault, requestMethod, myURL,
                               kCFHTTPVersion1_1);

CFHTTPMessageSetBody(myRequest, bodyData);
CFHTTPMessageSetHeaderFieldValue(myRequest, headerFieldName, headerFieldValue);
CFReadStreamRef myReadStream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, myRequest);

CFReadStreamOpen(myReadStream);

Answer 1

here is the solution , when you create the CFHTTPMessage you should serialize it (for example in my code I used UTF8 ) and then write to to server .

here is my code sample you can follow this example it is working great :

CFHTTPMessageRef myRequest = CFHTTPMessageCreateRequest(kCFAllocatorDefault,CFSTR("POST"), myURL, kCFHTTPVersion1_1);  
    CFHTTPMessageSetHeaderFieldValue(myRequest, CFSTR("Content-Type"), CFSTR("application/x-www-form-urlencoded"));
    CFHTTPMessageSetHeaderFieldValue(myRequest, CFSTR("Content-Length"), (CFStringRef)postLength);
    CFHTTPMessageSetBody(myRequest, (CFDataRef)postData); // postData is NSData 
dataReadStream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, myRequest);

//// From here Is Connection To Server

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, 
                                       (CFStringRef) serverHost, 
                                       serverPort, 
                                       &dataReadStream, 
                                       &dataWriteStream);

if (dataReadStream && dataWriteStream) {
    CFReadStreamSetProperty(dataReadStream, 
                            kCFStreamPropertyShouldCloseNativeSocket, 
                            kCFBooleanTrue);
    CFWriteStreamSetProperty(dataWriteStream, 
                             kCFStreamPropertyShouldCloseNativeSocket, 
                             kCFBooleanTrue);

    iStream = (NSInputStream *)dataReadStream;
    [iStream retain];
    [iStream setDelegate:self];
    [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop] 
                       forMode:NSDefaultRunLoopMode];
    [iStream open];

    oStream = (NSOutputStream *)dataWriteStream;
    [oStream retain];
    [oStream setDelegate:self];
    [oStream scheduleInRunLoop:[NSRunLoop currentRunLoop] 
                       forMode:NSDefaultRunLoopMode];
    [oStream open];

///Now Write Your Command To Server

NSString *content = [NSString stringWithFormat:@"Your Command"];
NSString *req = [NSString stringWithFormat:@"POST /client HTTP/1.1\r\nContent-Length: %d\r\n\r\n%@\r\n", [content length], content];

[oStream write:(const UInt8 *)[req UTF8String] maxLength:strlen((char*)[req UTF8String])];

then receive the notification in just dont Forget to add to header file

-(void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode