依赖hadoop,hive相关包，
源码见附件。
add jar hdfs://nn.dc.sh-wgq/group/p_sdo_data/p_sdo_data_etl/udf/base64.jar;
CREATE TEMPORARY FUNCTION encodebase64 AS 'com.sdo.hive.udf.EncodeBase64';
CREATE TEMPORARY FUNCTION decodebase64 AS 'com.sdo.hive.udf.DecodeBase64';
hive> select encodebase64('liuxiaowen1234') from lxw_t1 limit 1;
bGl1eGlhb3dlbjEyMzQ=
hive> select decodebase64('bGl1eGlhb3dlbjEyMzQ=') from lxw_t1 limit 1;
liuxiaowen1234