DataNucleus supports persistence to heterogeneous datastores and this plugin provides persistence to Excel.
'org.datanucleus:datanucleus-excel:2.1.2'
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-excel</artifactId>
<version>2.1.2</version>
</dependency>
<dependency org="org.datanucleus" name="datanucleus-excel" rev="2.1.2"/>
"org.datanucleus", "datanucleus-excel", "2.1.2"