nsurlconnection处理了多少个urlRequests [英] How many urlRequests are handled by nsurlconnection

问题描述

我必须在经过许多网站之后一次调用20个urlReqests我发现4个urlRequsts被处理后，接下来的请求将遇到错误，即超时错误。当我在循环中调用5个webservices时，前4个webservices是执行和第5次获取超时错误。如何处理这种情况
任何帮助将不胜感激

I have to call 20 urlReqests at a time after going through many websites i have found that 4 urlRequsts are handled after that next undergoing requests will encounter error that is timeout error.when i call 5 webservices in a loop first 4 webservices are executing and 5th gets timeout error.How to handle this situation Any help would be appreciated

推荐答案

您可以使用NSOperationQueue为了这样的任务。以下是示例代码 -

You can use NSOperationQueue for such tasks. Here is the sample code-

RequestManager.h的代码： -

Code for RequestManager.h :-

#import <Foundation/Foundation.h>

@protocol RequestManagerDelegate <NSObject>

@optional
- (void)requestForURL:(NSURL *)url tag:(NSString *)tag type:(NSString *)type
        didComplete:(NSData *)data;

- (void)requestForURL:(NSURL *)url tag:(NSString *)tag type:(NSString *)type
   didFailWithError:(NSError *)error;

@end



@interface RequestManager : NSObject

+ (RequestManager *) instance;

- (void)requestForURL:(NSURL *)url tag:(NSString *)tag delegate:(id<RequestManagerDelegate >)delegate;

@end

RequestManager.m的代码： -

Code for RequestManager.m :-

#import "RequestManager.h"

@interface RequestManager () {
    NSOperationQueue *requestQueue;
}

@end

@implementation RequestManager

static RequestManager *singletonInstance = nil;

- (id)init {
    if(self = [super init]) {
        requestQueue = [[NSOperationQueue alloc] init];
        requestQueue.maxConcurrentOperationCount = 2;//Here you can select maximum concurrent operations
    }
   return self;
  }


+ (RequestManager *) instance {
    @synchronized(self) {
        if(!singletonInstance) {
            singletonInstance = [[RequestManager alloc] init];
        }
    }
    return singletonInstance;
  }


- (void)requestForURL:(NSURL *)url tag:(NSString *)tag delegate:(id<RequestManagerDelegate >)delegate {
    [requestQueue setSuspended:YES];
    RequestOperation *newOperation = [[RequestOperation alloc] initWithURL:url tag:tag delegate:delegate];
    newOperation.queuePriority = NSOperationQueuePriorityVeryHigh;

    [requestQueue addOperation:newOperation];

    NSArray *operations = requestQueue.operations;

    long operationsCount = operations.count;
    RequestOperation *operation;

    NSOperationQueuePriority priority = NSOperationQueuePriorityVeryHigh;
    for(long i = (operationsCount - 1); i >= 0; i--) {
        operation = [operations objectAtIndex:i];

        if((operation.isExecuting || operation.isCancelled || operation.isFinished) == NO) {
            [operation setQueuePriority:priority];
            priority = [self nextPriorityLowerThan:priority];
        }
    }

    [requestQueue setSuspended:NO];
}

- (NSOperationQueuePriority)nextPriorityLowerThan:(NSOperationQueuePriority)priority {
NSOperationQueuePriority lowerPriority = NSOperationQueuePriorityVeryLow;

switch (priority) {
    case NSOperationQueuePriorityVeryHigh:
        lowerPriority = NSOperationQueuePriorityHigh;
        break;

    case NSOperationQueuePriorityHigh:
        lowerPriority = NSOperationQueuePriorityNormal;
        break;

    case NSOperationQueuePriorityNormal:
        lowerPriority = NSOperationQueuePriorityLow;
        break;

    case NSOperationQueuePriorityLow:
        lowerPriority = NSOperationQueuePriorityVeryLow;
        break;

    default:
        break;
 }

 return lowerPriority;
}

@end

现在RequestOperation.h - >

Now RequestOperation.h ->

#import <Foundation/Foundation.h>


@interface RequestOperation : NSOperation

@property(readonly, copy) NSURL *url;
@property(strong , readonly) NSString *tag;
@property(strong , readonly) id<RequestManagerDelegate > *delagate;

- (id)initWithURL:(NSURL *)url tag:(NSString *)tag delegate:(id<RequestManagerDelegate >) delegate;

@end

现在RequestOperation.m

Now RequestOperation.m

#import "RequestOperation.h"


@interface RequestOperation ()
{
   NSURLConnection *connection;

}
@property (nonatomic) long long int expectedContentLength;
@property (nonatomic, readwrite) NSError* error;
@property (nonatomic) BOOL isExecuting;
@property (nonatomic) BOOL isConcurrent;
@property (nonatomic) BOOL isFinished;
@end



@implementation RequestOperation

- (id)initWithURL:(NSURL *)url tag:(NSString *)tag delegate:(id<RequestManagerDelegate >) delegate{
    if ((self=[super init])) {
    _url = url;
    _tag = tag;
    _delagate=delagate;

   }
   return self;
 }


- (void)start
  {
   NSURLRequest* request = [NSURLRequest requestWithURL:_url];
   //handle here for your request type (post or get)
   self.isExecuting = YES;
   self.isConcurrent = YES;
   self.isFinished = NO;
   [[NSOperationQueue mainQueue] addOperationWithBlock:^
     {
     connection = [NSURLConnection connectionWithRequest:request delegate:self];
     }];
  }

- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response {
    return request;
  }

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
  {

  }

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

  }


  - (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse {
    return cachedResponse;

  }

 - (void)connectionDidFinishLoading:(NSURLConnection *)connection {
      self.isExecuting = NO;
      self.isFinished = YES;
   }

 - (void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)error
   {
     self.error = error;
     self.isExecuting = NO;
     self.isFinished = YES;
   }

 - (void)setIsExecuting:(BOOL)isExecuting
   {
     [self willChangeValueForKey:@"isExecuting"];
     _isExecuting = isExecuting;
     [self didChangeValueForKey:@"isExecuting"];
   }

 - (void)setIsFinished:(BOOL)isFinished
   {
    [self willChangeValueForKey:@"isFinished"];
    _isFinished = isFinished;
    [self didChangeValueForKey:@"isFinished"];
   }

 - (void)cancel
   {
    [super cancel];
    [connection cancel];
    self.isFinished = YES;
    self.isExecuting = NO;
   }

@end

我给了你我的代码，这就是我如何异步管理多个并发请求。你可以使用它非常有效。您可以在RequestManager.h中使用方法声明请求url，并可以使用委托来处理结果。

I given you the my code , this is how i managed multiple concurrent request asynchrounously. You can use this it is very effective. You can request the url using method declare in RequestManager.h and can handle the result using delegates.

这篇关于nsurlconnection处理了多少个urlRequests的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！