NSOperation 实现 HTTP多线程访问

                                                       NSOperation 实现 HTTP多线程访问

1。  从 NSOperation 派生出自己的类

 

       #define TWITTER_URL_GET_LIST_NUMS @"http://www.xxxyyy.com/ports/miniblog/get_counts_by_account?a=%@&t=%@&f=iphone"

 

       @protocol TwitterGetListNumsDelegate<NSObject>- (void) doneTwitterGetListNumbs:(NSData *) data;@end@interface TwitterGetListNumsOperation : NSOperation{id<TwitterGetListNumsDelegate> delegate;NSString * nsAccount;NSString * token_signature;NSString * queryAccount;}@property(retain) id delegate;@property(retain) NSString * nsAccount; @property(retain) NSString * token_signature;@property(retain) NSString * queryAccount;@end 

 

       @implementation TwitterGetListNumsOperation@synthesize delegate;@synthesize nsAccount;@synthesize token_signature;@synthesize queryAccount;- (void) cleanup: (NSData*) data{if (self.delegate && [self.delegate respondsToSelector:@selector(doneTwitterGetListNumbs:)])[self.delegate doneTwitterGetListNumbs:data];}- (void) main{NSString* token_url_encoded = URLENCODING(token_signature);NSString* baseUrl = [NSString stringWithFormat:TWITTER_URL_GET_LIST_NUMS, nsAccount,token_url_encoded];// Establish the Twitter API requestNSURL *url = [NSURL URLWithString:baseUrl];NSLog(@"xxx - TWITTER_URL_GET_LIST_NUMS, url=%@", url);NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];if (!urlRequest) NOTIFY_AND_LEAVE(nil);//Error creating the URL Request[urlRequest setHTTPMethod: @"POST"];[urlRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];[urlRequest setValue:@"XXXYYY" forHTTPHeaderField:@"X-XXXYYY-Client"];NSString* strData = [NSString stringWithFormat:@"account=%@", queryAccount];NSLog(@"xxx - strData=%@", strData);NSData* postData = [strDatadataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];[urlRequest setHTTPBody:postData];NSError *error;NSURLResponse *response;NSData *tw_result = [NSURLConnection sendSynchronousRequest:urlRequest returningResponse:&response error:&error];if (!tw_result) {NSString *tw_output = [NSString stringWithFormat:@"Submission error: %@", [error localizedDescription]];NSLog(@"%@", tw_output);NOTIFY_AND_LEAVE(nil);} else {//std::string output = (char*)[ bytes];[self cleanup:tw_result];}}@end 

 

 

2.  在类里面 实现   TwitterGetListNumsDelegate， SBJsonStreamParserAdapterDelegate 两个代理。

 

     类里面声明以下变量：

 

     SBJsonStreamParser *num_parser;

     SBJsonStreamParserAdapter *num_adapter;

 

 

     实现 TwitterGetListNumsDelegate  协议：

 

     - (void) doneTwitterGetListNumbs:(NSData *) data{[self performSelectorOnMainThread:@selector(jsonParserFetchData:) withObject:data waitUntilDone:NO];} 

 

     - (void) jsonParserFetchData : (NSData*) data{FLOG(@"xxx - http get lsitnums done.");if(data.length == 0){[num_parser release];[num_adapter release];num_parser = nil;num_adapter = nil;return;}// Parse the new chunk of data. The parser will append it to// its internal buffer, then parse from where it left off in// the last chunk.std::string a = (char*)[data bytes];LOG(LS_VERBOSE)<<a;SBJsonStreamParserStatus status = [num_parser parse:data];if (status == SBJsonStreamParserError) {NSLog(@"Parser error: %@", num_parser.error);} else if (status == SBJsonStreamParserWaitingForData){NSLog(@"Parser waiting for more data");}[num_parser release];[num_adapter release];num_parser = nil;num_adapter = nil;} 

     在这个函数里面，调用JSON  PARSER  去解析结果。

 

 

    下面是 实现 JSON  PArser 协议：

 

     - (void)parser:(SBJsonStreamParser *)parser foundArray:(NSArray *)array{NSLog(@"ArrayTweet: '%@'", array);} 

 

     - (void)parser:(SBJsonStreamParser *)parser foundObject:(NSDictionary *)dict {//获得列表数量if (parser==num_parser) {NSNumber *result = [dict objectForKey:@"result"];FLOG(@"xxx - SBJsonStreamParser result: '%d'", [result intValue]);if ([result intValue]) {NSDictionary *data = [dict objectForKey:@"data"];NSLog(@"xxx - tableView reloadData", data);NSNumber* BlogNum= [data objectForKey:@"blog_num"];NSNumber* FollowNum=[data objectForKey:@"follow_num"];NSNumber* FansNum=[data objectForKey:@"fans_num"];NSString *strBlogNum=[[BlogNum stringValue] UTF8String];NSString *strFollowNum=[[FollowNum stringValue] UTF8String];NSString *strFansNum=[[FansNum stringValue] UTF8String];}}} 

 

 

3.   如何调用这个呢？

     - (void) getListNum{num_adapter = [SBJsonStreamParserAdapter new];num_adapter.delegate = self;num_parser = [SBJsonStreamParser new];num_parser.delegate = num_adapter;num_parser.multi = YES;std::string username = @"";std::string token_signature = @"";TwitterGetListNumsOperation *operation = [[[TwitterGetListNumsOperation alloc] init] autorelease];operation.delegate = self;operation.nsAccount = [NSString stringWithCString:username.c_str() encoding:NSUTF8StringEncoding];operation.token_signature = [NSString stringWithCString:token_signature.c_str() encoding:NSUTF8StringEncoding];operation.queryAccount= [NSString stringWithCString:twitter_item_.account.c_str() encoding:NSUTF8StringEncoding];NSOperationQueue *queue = [[[NSOperationQueue alloc] init] autorelease];[queue addOperation:operation];} 

 

 

 

如果有多个类型的NSOperation同时在一个类中进行，就创建多个 adapter和 parser，通过这个来判断是那个Operation的结果。而且由于

是多线程，所以在返回结果的时候，可能会导致crash，采取的办法是，等一个HTTP Operation操作结果返回以后，再进行下一个HTTP Opeation操作。