// //1、json转换成对象
// NSString * path = [[NSBundle mainBundle] pathForResource:@"test.json" ofType:nil];
// NSData * data = [NSData dataWithContentsOfFile:path];
// NSDictionary * dic = [ NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
// NSArray * array = dic[@"class1"];
//
// for (NSDictionary * dic in array)
// {
//
// //2.对象转成data
// NSData * data = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];
// NSString * str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
// NSLog(@"%@", str);
//
// }