Objective-C使用Cookie的异步Web请求

Question

我正在使用Objective-C编写一个程序,我需要向Web服务器发出Web请求,但异步并且我在mac上相当新,我非常擅长windows技术,但我需要知道如果我使用NSOperation(介绍)在10.5中,我假设它不会在10.4 MAC中运行？),或者如果它被实现使得它使用将在10.4上可用的系统线程？

或者我应该创建一个新的线程并创建一个新的runloop,如何使用cookie等,如果有人能给我一个小例子,这将是非常有帮助的.如果可能的话,我希望这个示例也可以在mac 10.4上运行.

Answer 1

有一个很好的例子,使用NSURLRequest和NSHTTPCookies来完成登录网站的完整Web应用程序示例,存储SessionID cookie并在将来的请求中重新提交.

NSURLConnection,NSHTTPCookie

通过logix812:

    NSHTTPURLResponse   * response;
    NSError             * error;
    NSMutableURLRequest * request;
    request = [[[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://temp/gomh/authenticate.py?setCookie=1"]
                                            cachePolicy:NSURLRequestReloadIgnoringCacheData 
                                        timeoutInterval:60] autorelease];

    [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];  
    NSLog(@"RESPONSE HEADERS: \n%@", [response allHeaderFields]);

    // If you want to get all of the cookies:
    NSArray * all = [NSHTTPCookie cookiesWithResponseHeaderFields:[response allHeaderFields] forURL:[NSURL URLWithString:@"http://temp"]];
    NSLog(@"How many Cookies: %d", all.count);
    // Store the cookies:
    // NSHTTPCookieStorage is a Singleton.
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:all forURL:[NSURL URLWithString:@"http://temp"] mainDocumentURL:nil];

    // Now we can print all of the cookies we have:
    for (NSHTTPCookie *cookie in all)
        NSLog(@"Name: %@ : Value: %@, Expires: %@", cookie.name, cookie.value, cookie.expiresDate); 


    // Now lets go back the other way.  We want the server to know we have some cookies available:
    // this availableCookies array is going to be the same as the 'all' array above.  We could 
    // have just used the 'all' array, but this shows you how to get the cookies back from the singleton.
    NSArray * availableCookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookiesForURL:[NSURL URLWithString:@"http://temp"]];
    NSDictionary * headers = [NSHTTPCookie requestHeaderFieldsWithCookies:availableCookies];

    // we are just recycling the original request
    [request setAllHTTPHeaderFields:headers];

    request.URL = [NSURL URLWithString:@"http://temp/gomh/authenticate.py"];
    error       = nil;
    response    = nil;

    NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    NSLog(@"The server saw:\n%@", [[[NSString alloc] initWithData:data encoding: NSASCIIStringEncoding] autorelease]);

Answer 2

对于异步请求,您需要使用NSURLConnection.

对于cookie,请参阅NSHTTPCookie和NSHTTPCookieStorage.

更新:

下面的代码是来自我的一个应用程序的真实代码.在类接口中responseData定义NSMutableData*.

- (void)load {
    NSURL *myURL = [NSURL URLWithString:@"http://stackoverflow.com/"];
    NSURLRequest *request = [NSURLRequest requestWithURL:myURL
                                             cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                         timeoutInterval:60];
    [[NSURLConnection alloc] initWithRequest:request delegate:self];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    responseData = [[NSMutableData alloc] init];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [responseData appendData:data];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [responseData release];
    [connection release];
    // Show error message
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    // Use responseData
    [responseData release];
    [connection release];
}