Working with the relation service - JMX in Action - page 274

server.createMBean( "javax.management.relation."
+"RelationService",
relationServiceName,
params,
signature);
}
catch(Exception e)
{
System.out.println("Error Creating the Relation"
+ " Service MBean");
e.printStackTrace();
}
}

You create the relation service by registering the RelationService MBean ( javax.
management.relation.RelationService ) with the JMXBookAgent . The MBean con-
structor takes a single argument, a boolean , which indicates whether the service
should immediately purge a relation that has become invalid due to an invalid
Role . Remember, a relation is invalid when a participating MBean of the relation
is removed from the agent. If you set this value to true , whenever the relation
service notices that an MBean associated with a relation has been unregistered, it
will also remove the MBean reference from the role values. If the role is no
longer valid according to the cardinality of the RoleInfo , the relation will also be
removed. If you set this boolean value to false , the relation will be purged only if
the purgeRelations() method is called on the RelationService MBean.

11.3.6 Adding a new relation to the relation service

You have created all the necessary MBeans and set up the services to start a rela-
tion. The final step is to instantiate an instance of the CtlRelation MBean and
add it to the relation service (as well as register it in the agent). Listing 11.10 cre-
ates the relation by using the addRelation() method of the RelationService
MBean. Again, the listing is from the RelationMain class that will execute the
entire example.

Listing 11.10 createRelation() method from RelationMain

public void createRelation()
{
System.out.println("\n>>> CREATE EXTERNAL RELATION of "
+ " type myRelationType");
try
{
//register the relation MBean