Hi
I'm using ignite with cassandra as persistent store. I have a POJO class
mapped to cassandra table. I have used
ignite-cassandra-store/KeyValuePersistenceSettings xml bean to map POJO to
cassandra table. In the POJO one of the fields is Integer (wrapper class)
mapped to int column in cassandra table. When I load any row having this int
field as null in cassandra, I'm getting that respective field in POJO as 0,
which is default value of primitive type int. Same is the case when using
other wrapper classes. How can I get that field as null when the actual
column field is null in cassandra, since wrapper object can be null.
I found a work around by using custom class extending CacheStoreAdapter and
using this class in cache configuration in cacheStoreFactory
property,instead of using ignite-cassandra-store. This class overrides
load,write and delete methods. In load method I connect to cassandra
database using Datastax driver, and load respective row depending upon the
key passed as parameter to load, and then create a new POJO whose fields are
set to the fields of row returned from cassandra and return the POJO. During
this process I make a check if the int field that I mentioned above is null
in cassandra by using Row.isNull method of Datastaxdriver and if its not
null only then I set POJO field to the field value returned from cassandra,
else it will remain as null.
Is it a bug in ignite-cassandra-store, where I cannot retain null value of
cassandra table field for primitive types mapped to wrapper classes in POJO
in ignite? The reason I have used wrapper class objects is to identify if
its null in cassandra or not, but there seems no way to differentiate
between primitive type default value and null when using
ignite-cassandra-store.
I found in the ignite source code that in org.apache.ignite.cache.store.cassandra.common.PropertyMappingHelper.getCassandraColumnValue(..) method there is no check being made to see if the column value is null or not for Integer,Float,Double,Long or Boolean. Here directly getInt,getFloat etc.. are called without making a check if the column value is null or not. From Datastax documentation we can see that getInt returns 0 if column value is null and similarly getLong returns 0L , getDouble return 0.0 etc.. But for String -> getString returns null if column value is null and also same for Date etc... Hence for primitive types I guess there should be an additional check to see if the column value is null.
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