没有使用 ftp 协议调用 didReceiveAuthenticationChallenge

Question

我的应用程序中出现 NSURLConnection 问题已经苦苦挣扎了几天。我需要连接到服务器（调用 getPdfFromServerAtIndex），使用 ftp 协议来获取对象（pdf 页面，但没关系！）。当我尝试连接到 http url 时，我没有问题。对于要求身份验证的 http url，同样的事情，我的所有委托方法都会被调用。

但是当我使用下面显示的 url 时，使用 ftp 协议构建，委托方法如 didReceiveAuthenticationChallenge、canAuthenticateAgainstProtectionSpace 永远不会被调用。

当 "while(!finished)" 循环时，仅调用 connectionShouldUseCredentialStorage 方法，然后 didFailWithError 方法给我错误“连接失败！错误 - 您无权访问请求的资源。ftp://ftp.www.thephilosopher.org/ ”。然而，当我尝试在浏览器上粘贴 ftp url 时，我被要求填写用户名和密码。

知道为什么使用 ftp 协议我无法验证和访问服务器吗？

-(void)getPdfFromServerAtIndex:(NSUInteger)index{

// Create the request.
// Set finished to false
finished = FALSE;

NSString *pageNumber = [NSString stringWithFormat:@"ftp://ftp.www.thephilosopher.org/Iphone/0%i.pdf",index+1];

NSURL* nsurl = [NSURL URLWithString:pageNumber];
urlReq = [[NSMutableURLRequest alloc] initWithURL:nsurl];
BOOL canHandle = [NSURLConnection canHandleRequest:urlReq];


NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:urlReq delegate:self];


if (conn && canHandle) {
    // Create the NSMutableData to hold the received data.
    // receivedData is an instance variable declared elsewhere.
    receivedData = [[NSMutableData data] retain];
} else {
    // Inform the user that the connection failed.
    NSLog(@"Connection Failed!");
}


while(!finished) {
    [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];}
}  

-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
finished = TRUE;

// receivedData is declared as a method instance elsewhere
NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]);

// release the connection, and the data object
[connection release];
}  

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace*)tmpProtectionSpace {
// Check the NSURLProtectionSpace
return YES;}  

-(NSURLRequest *)connection:(NSURLConnection *)inConnection willSendRequest:(NSURLRequest *)inRequest redirectResponse:(NSURLResponse *)inRedirectResponse{       
if(inRedirectResponse){
    NSMutableURLRequest *r = [[urlReq mutableCopy] autorelease]; // original request
    [r setURL: [inRequest URL]];
    return r;
} else {
    return inRequest;
}
}  

-(BOOL)connectionShouldUseCredentialStorage:(NSURLConnection*)connection{
 NSLog(@"connectionShouldUseCredentialStorage");
 return YES;
}  

-(void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge{
if([challenge previousFailureCount] == 0) {
    NSURLCredential *newCredential;
    newCredential=[NSURLCredential credentialWithUser:@"XXXX" password:@"XXXXX" persistence:NSURLCredentialPersistenceNone];
[[challenge sender] useCredential:newCredential forAuthenticationChallenge:challenge];}
else {
[[challenge sender] cancelAuthenticationChallenge:challenge];
NSLog(@"Bad Username Or Password");}
}  

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
// release the connection, and the data object
[connection release];
// receivedData is declared as a method instance elsewhere
[receivedData release];

// inform the user
NSLog(@"Connection failed! Error - %@ %@",
      [error localizedDescription],
      [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}  

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{

NSLog(@"Data received");
[receivedData appendData:data];
}  

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
NSLog(@"Response received");
[receivedData setLength:0];
}  

Answer 1

只需以“ftp://username:password@ipaddress/filepath/”格式发出 NSURL

在你的情况下：ftp://username:password@ftp.www.thephilosopher.org/Iphone/0%i.pdf