Create following discovery rule:
Item prototype with key
Now discover attributes such as "s.i.m.p.l.e" (The app name) = My MBean name
"s.i.m.p.l.e" MBean name works and discovered "s\.i\.m\.p\.l\.e"
item "Zabbix server:jmx[com.example:type=Hello, s.i.m.p.l.e]" became not supported: getAttribute failed: ModelMBeanAttributeInfo not found for s