请求Json数据，并且解析Json数据

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"https://api.douban.com/v2/book/search?tag=computer"]];
    //将请求的url数据放到NSData对象中
    NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    //IOS5自带解析类NSJSONSerialization从response中解析出数据放到字典中
    NSDictionary *weatherDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];
   
    NSArray *localdata=[weatherDic objectForKey:@"books"];