You need to
1. Use the jboss specific *-service.xml file to deploy your mbean (rather than using mlets or some other way I can't think of)
2. Use the mbean dependency mechanism to make your mbean wait for the datasource mbeans to deploy.
The simplest way to do this is to look in jmx-console for the connection manager mbean for your datasource config: lets pretend it is jboss.jca:service=LocalTxCM,name=OracleDS
Then include in your mbean config