How to manage multiple asynchronous NSURLConnection request

问题

I am making 3 NSURLConnection requests on app start and exit in appdelegate.m, I am using asynchronous call, the response returned is array of dictionaries, with array having same name in all responses, so I cannot check with key.

So I tried declaring NSURLConnection variables in appdelgate.h and then in connectionDidFinishloading compared each declared connection object with connection paramter

//Appdelegate.h

NSURLConnection *conn1;
 NSURLConnection *conn2;
 NSURLConnection *conn3;

then in //Appdelgate.m

- (void)applicationDidBecomeActive:(UIApplication *)application
{

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://xyz/login"]];        

          request setValue:@"application/json;charset=utf-8" forHTTPHeaderField:@"Content-Type"];

            [request setHTTPMethod:@"GET"];

            conn1 = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];

            [conn1 start];

}

then

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    // The request is complete and data has been received
    // You can parse the stuff in your instance variable now


    NSError *e = nil;
    NSDictionary *response = [NSJSONSerialization JSONObjectWithData: m_responseData options: 0 error: &e];


    //Extracy spcific keys and add to respective arrays

    if(connection == conn1)
    {
        //call 2 nd request
    }

    if(connection == conn2)
    {
        //call 3 rd request
    }
}

I checked info of connection object, it always shows me this

<NSURLConnection: 0x14d09c20> { request: <NSMutableURLRequest: 0x14d0ac70> { URL: http://xyz/login } }

Even after calling second request it still shows me first request.

So comparison is failing..

So what can be better approach for this, or is it I am missing something.

回答1:

use just like

  NSURLConnection *itemIdConnection,*contactNameConnection;
  NSMutableData *receivedData, *locationData;

and your delegate method is

 #pragma NSUrlConnectionDelegate Methods

-(void)connection:(NSConnection*)conn didReceiveResponse:(NSURLResponse *)response
{

if(connection == itemIdConnection)
{
      if (receivedData == NULL)
{
    receivedData = [[NSMutableData alloc] init];
}
   [receivedData setLength:0];
}

if(connection == contactNameConnection)
{
    if (locationData == NULL)
{
    locationData = [[NSMutableData alloc] init];
}

   [locationData setLength:0];
}



}

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

if (connection==itemIdConnection) {
[receivedData appendData:data];
}
if(connection == contactNameConnection)
{
[locationData appendData:data];
}

}

 - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
  NSLog(@"Connection failed! Error - %@ %@",
      [error localizedDescription],
      [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
 UIAlertView *customAlert = [[UIAlertView alloc]initWithTitle:@"No NetWork" message:@"Interet Connection is Lost" delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
[customAlert show];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{


if (connection==itemIdConnection) {
//        NSError *e = nil;
    NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:receivedData options: kNilOptions error:nil];
    NSString *tmp=[[NSString alloc]initWithData:receivedData encoding:NSUTF8StringEncoding];
    NSLog(@"%@", tmp);
    NSLog(@"  parsing JSON: %@", jsonDict);


      }

 if (connection==contactNameConnection) {
  NSError *e = nil;
     NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:locationData options: NSJSONReadingMutableContainers error: &e];
     NSLog(@"  parsing JSON: %@", jsonDict);
 }



}

来源：https://stackoverflow.com/questions/24075772/how-to-manage-multiple-asynchronous-nsurlconnection-request

标签

ios

json

asynchronous

nsurlconnection