NSMutableURLRequest Http 请求 同步 异步

#pragma mark  get country code//同步
-(void)getFKjsonCountryCode
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, ), ^{

        NSString *urlString = [NSString stringWithFormat:@"http://www.baidu.com"];
        NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
        [request setURL:[NSURL URLWithString:urlString]];
        [request setHTTPMethod:@"POST"];
        //post
        [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
        [request setValue:@"ios" forHTTPHeaderField:@"X-Channel"];
        [request setValue:@"" forHTTPHeaderField:@"X-APP-ID"];
        NSHTTPURLResponse* urlResponse = nil;
        NSError *error = nil;
        NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];
        //NSString *result = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
        NSDictionary *countryDic = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableLeaves error:&error];
        if ([urlResponse statusCode] >=  && [urlResponse statusCode] < )
        {
            NSMutableArray * countryArr =  [[countryDic objectForKey:@"data"]objectForKey:@"phone_codes"];
            if(countryArr)
            {
                for(int i = ; i<[countryArr count]; i++)
                {
                    NSLog(@"countryCode:%@ %@",[[countryArr objectAtIndex:i]objectForKey:@"country"],[[countryArr objectAtIndex:i]objectForKey:@"code"]);
                }
            }
            // NSLog(@"12:%@",[[[[weatherDic objectForKey:@"data"]objectForKey:@"phone_codes"]objectAtIndex:0]objectForKey:@"country"]);
        }
        else
        {

        }

    });
}

#pragma mark  get country code //异步
-(void)getFKjsonCountryCodeAsync
{
    NSString *urlString = [NSString stringWithFormat:@"http://www.baidu.com"];
    // 初始化请求
    NSMutableURLRequest  *request = [[NSMutableURLRequest alloc] init];
    // 设置
    [request setURL:[NSURL URLWithString:urlString]];
    [request setCachePolicy:NSURLRequestUseProtocolCachePolicy]; // 设置缓存策略
    [request setTimeoutInterval:20.0]; // 设置超时
    [request setHTTPMethod:@"POST"];
    //......

    //    receivedData = [[NSMutableData alloc] initData: nil];
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request     delegate:self];
    if (connection == nil) {
        NSLog(@"errors");
        // 创建失败
        return;
    }
}

// 收到回应
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    NSLog(@"receive the response");

}
// 接收数据
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{

    NSError *error = nil;
    NSDictionary *countryDic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];
    NSMutableArray * countryArr =  [[countryDic objectForKey:@"data"]objectForKey:@"phone_codes"];
    if(countryArr)
    {

        for(int i = ; i<[countryArr count]; i++)
        {
            NSLog(@"countryCode:%@ %@",[[countryArr objectAtIndex:i]objectForKey:@"country"],[[countryArr objectAtIndex:i]objectForKey:@"code"]);
        }
    }

}
// 数据接收完毕
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{

    NSLog(@"finishLoading");
}
// 返回错误
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{

    NSLog(@"Connection failed: %@", error);
}