e72bfd15_Cassandra_vs_HBase___WhyNosql__Cassandra
[HBase] Has a nice native java api. Feels much more java system than Cassandra. Being a java shop, it was important for us. HBase has a thrift interface for other laguages too. [Cassandra] 
Does not have a native java api as of now. No java doc. Even though written in Java, you have to use Thrift to communicate with the cluster.
Cassandra vs HBase | WhyNosql
Cassandra