+ (NSString*)stringINJSONFormatForObject:(id)obj{    NSData *jsonData =http://www.mamicode.com/ [NSJSONSerialization dataWithJSONObject:obj                                                       options:0 // If that option is not set, the most compact possible JSON will be generated                                                         error:nil];    NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];    jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];  //去除掉首尾的空白字符和换行字符    return jsonString;}

+ (NSDictionary *)dictForJSONString:(NSString *)str{    NSData *jsonData =http://www.mamicode.com/ [str dataUsingEncoding:NSUTF8StringEncoding];    NSError *err;    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData                                                        options:NSJSONReadingMutableContainers                                                          error:nil];    return dic;}