NSURLRequest:如何处理重定向的帖子？

Question

我有一个经过试验和测试的NSURLRequest(和伴奏)实现,它适用于GET和给定URL的POST.

但是,我现在想要移动URL的目标而不更改应用程序使用的URL,所以我打算通过我的DNS提供程序使用webhop重定向.

这适用于GET请求,但POST只是挂起...没有收到连接响应.

处理重定向的相关iOS方法是,

-(NSURLRequest *)connection:(NSURLConnection *)connection
    willSendRequest:(NSURLRequest *)request
    redirectResponse:(NSURLResponse *)redirectResponse

根据Apple的(处理重定向)文档,

如果委托未实现连接:willSendRequest:redirectResponse:,则允许所有规范更改和服务器重定向.

嗯,这不是我的经验,因为退出这个方法对我不起作用.请求只是挂起而没有响应.

Apple还建议实施willSendRequest(参见上面链接的Apple文档),这再次对我不起作用.我看到了调用,但结果请求只是挂起.

我目前对willSendRequest的实现如下(见下文).这是在重定向之后,但处理请求就好像它是一个GET而不是POST.

我认为问题在于重定向正在失去HTTP请求是POST的事实(可能存在更多问题,例如承载请求Body也是如此？).

我不确定我应该在这做什么.因此,任何有关如何正确处理接收重定向的POST的建议都将受到赞赏.谢谢.

-(NSURLRequest *)connection:(NSURLConnection *)connection
   willSendRequest:(NSURLRequest *)request
  redirectResponse:(NSURLResponse *)redirectResponse
{

    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) redirectResponse;

    int statusCode = [httpResponse statusCode];


    NSLog (@"HTTP status %d", statusCode);

    // http statuscodes between 300 & 400 is a redirect ...
    if (httpResponse && statusCode >= 300 && statusCode < 400)
    {
        NSLog(@"willSendRequest (from %@ to %@)", redirectResponse.URL, request.URL);
    }

    if (redirectResponse)
    {
        NSMutableURLRequest *newRequest = [request mutableCopy]; // original request

       [newRequest setURL: [request URL]];

       NSLog (@"redirected");

       return newRequest;
    }
    else
    {
        NSLog (@"original");

       return request;
    }
}

其他信息1

willSendRequest接收的HTTP代码是301 - '永久移动.

使用allHTTPHeaderFields来提取标题字段,我看到他请求我最初提交的标题

HTTP header {
  "Content-Length" = 244;
  "Content-Type" = "application/json";
}

...并且复制/重定向的请求具有标题,

Redirect HTTP header {
  Accept = "*/*";
  "Accept-Encoding" = "gzip, deflate";
  "Accept-Language" = "en-us";
  "Content-Type" = "application/json";
}

...看起来不像原始请求的副本,甚至是超集.

Answer 1

保持你的原始请求,然后提供自己的willSendRequest:redirectResponse:自定义该请求,而不是与一个苹果提供你的工作.

- (NSURLRequest *)connection: (NSURLConnection *)connection
             willSendRequest: (NSURLRequest *)request
            redirectResponse: (NSURLResponse *)redirectResponse;
{
    if (redirectResponse) {
        // The request you initialized the connection with should be kept as
        // _originalRequest.
        // Instead of trying to merge the pieces of _originalRequest into Cocoa
        // touch's proposed redirect request, we make a mutable copy of the
        // original request, change the URL to match that of the proposed
        // request, and return it as the request to use.
        //
        NSMutableURLRequest *r = [_originalRequest mutableCopy];
        [r setURL: [request URL]];
        return r;
    } else {
        return request;
    }
}

通过这样做,您明确忽略了HTTP规范的某些方面:重定向通常应转换为GET请求(取决于HTTP状态代码).但实际上,当从iOS应用程序进行POST时,此行为将更好地为您提供服务.

也可以看看:

• iOS开发人员库,URL加载系统编程指南:处理重定向和其他请求更改