使用 JsonSerDe 并使用以下语法创建表：

hive> create table sample(key1 string,key2 struct<nestedKey1:int,nestedKey2:int>) 
      ROW FORMAT SERDE 'org.apache.hive.hcatalog.data.JsonSerDe';

hive> select key1,key2.nestedkey1,key2.nestedkey2 from sample;
+---------+-------------+-------------+--+
|  key1   | nestedkey1  | nestedkey2  |
+---------+-------------+-------------+--+
| value1  | 1           | 2           |
+---------+-------------+-------------+--+

hive> select * from sample;
+--------------+----------------------------------+--+
| sample.key1  |           sample.key2            |
+--------------+----------------------------------+--+
| value1       | {"nestedkey1":1,"nestedkey2":2}  |
+--------------+----------------------------------+--+

（或）
如果你想用“展平”创建表格 json fields 然后使用 RegexSerDe 匹配regex从数据中提取nestedkey。
有关regex serde的更多详细信息，请参阅此链接。
更新：
输入数据：

{"key1":"value1","key2":{"nestedKey1":1,"nestedKey2":2}}

Hive：

hive> CREATE  TABLE dd (key1 string, nestedKey1 string, nestedKey2 string) 
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.RegexSerDe' 
WITH SERDEPROPERTIES 
('input.regex'=".*:\"(.*?)\",\"key2\":\\{\"nestedKey1\":(\\d),\"nestedKey2\":(\\d).*$");

从表中选择数据：

hive>  select * from dd;
+---------+-------------+-------------+--+
|  key1   | nestedkey1  | nestedkey2  |
+---------+-------------+-------------+--+
| value1  | 1           | 2           |
+---------+-------------+-------------+--+