Fix NullPointerException

[linchen059]

NullPointerException happens when retrieve null DateTime from clickhouse.

clickhouse-jdbc version is :

com.clickhouse clickhouse-jdbc 0.3.2

[github-actions]

Benchmark                                 (client)  (connection)  (statement)  (type)   Mode  Cnt     Score     Error  Units
Basic.insertOneRandomNumber  clickhouse-http-jdbc1         reuse       normal  object  thrpt   20   213.182 ±  27.237  ops/s
Basic.insertOneRandomNumber  clickhouse-http-jdbc1         reuse     prepared  object  thrpt   20   206.152 ±  28.541  ops/s
Basic.insertOneRandomNumber  clickhouse-http-jdbc1           new       normal  object  thrpt   20   210.618 ±  28.504  ops/s
Basic.insertOneRandomNumber  clickhouse-http-jdbc1           new     prepared  object  thrpt   20   208.050 ±  29.557  ops/s
Basic.insertOneRandomNumber   clickhouse-grpc-jdbc         reuse       normal  object  thrpt   20   217.434 ±  22.953  ops/s
Basic.insertOneRandomNumber   clickhouse-grpc-jdbc         reuse     prepared  object  thrpt   20   219.564 ±  20.699  ops/s
Basic.insertOneRandomNumber   clickhouse-grpc-jdbc           new       normal  object  thrpt   20   223.592 ±  28.397  ops/s
Basic.insertOneRandomNumber   clickhouse-grpc-jdbc           new     prepared  object  thrpt   20   218.936 ±  23.389  ops/s
Basic.selectOneRandomNumber  clickhouse-http-jdbc1         reuse       normal  object  thrpt   20  1133.484 ± 108.659  ops/s
Basic.selectOneRandomNumber  clickhouse-http-jdbc1         reuse     prepared  object  thrpt   20  1193.158 ± 108.218  ops/s
Basic.selectOneRandomNumber  clickhouse-http-jdbc1           new       normal  object  thrpt   20  1158.862 ±  89.450  ops/s
Basic.selectOneRandomNumber  clickhouse-http-jdbc1           new     prepared  object  thrpt   20  1129.555 ±  98.422  ops/s
Basic.selectOneRandomNumber   clickhouse-grpc-jdbc         reuse       normal  object  thrpt   20   777.052 ±  55.692  ops/s
Basic.selectOneRandomNumber   clickhouse-grpc-jdbc         reuse     prepared  object  thrpt   20   752.043 ±  79.165  ops/s
Basic.selectOneRandomNumber   clickhouse-grpc-jdbc           new       normal  object  thrpt   20   750.044 ±  65.263  ops/s
Basic.selectOneRandomNumber   clickhouse-grpc-jdbc           new     prepared  object  thrpt   20   729.970 ±  69.826  ops/s

[zhicwu]

Thanks for fixing the issue. Actually value == null is not needed as getValue will always return a non-null garbage free value object. I'll update the code, add test and release a patch over on Sunday if nothing else shows up in these two days.