[Java] JsonPrinter does not handle empty groups #800
Description
Similar to #799, seems if the group is empty, you end up with just a [\n
Dummy message that I think reproduces this:
<sbe:message name="myMessage" id="6">
<field name="myId" id="2" type="uint32"/>
<group name="myGroupInfo" id="7" dimensionType="groupSizeEncoding">
<field name="internalId" id="2" type="idtype"/>
<field name="otherId" id="3" type="idType"/>
</group>
<data name="rawStringId" id="100" type="varDataEncoding"/>
</sbe:message>
results in:
{
"myId": 0,
"myGroupInfo": [
"rawStringId": ""
}