MBeanRegistration
, Relation
, RelationSupportMBean
public class RelationSupport extends Object implements RelationSupportMBean, MBeanRegistration
RelationSupport class conforms to the design patterns of standard MBean. So the user can decide to instantiate a RelationSupport object himself as a MBean (as it follows the MBean design patterns), to register it in the MBean Server, and then to add it in the Relation Service.
The user can also, when creating his own MBean relation class, have it extending RelationSupport, to retrieve the implementations of required interfaces (see below).
It is also possible to have in a user relation MBean class a member being a RelationSupport object, and to implement the required interfaces by delegating all to this member.
RelationSupport implements the Relation interface (to be handled by the Relation Service).
It implements also the MBeanRegistration interface to be able to retrieve the MBean Server where it is registered (if registered as a MBean) to access to its Relation Service.
Constructor | Description |
---|---|
RelationSupport |
Creates a RelationSupport object. |
RelationSupport |
Creates a RelationSupport object. |
Modifier and Type | Method | Description |
---|---|---|
RoleResult |
getAllRoles() |
Returns all roles present in the relation. |
Map |
getReferencedMBeans() |
Retrieves MBeans referenced in the various roles of the relation. |
String |
getRelationId() |
Returns relation identifier (used to uniquely identify the relation inside the Relation Service). |
ObjectName |
getRelationServiceName() |
Returns ObjectName of the Relation Service handling the relation. |
String |
getRelationTypeName() |
Returns name of associated relation type. |
List |
getRole |
Retrieves role value for given role name. |
Integer |
getRoleCardinality |
Returns the number of MBeans currently referenced in the given role. |
RoleResult |
getRoles |
Retrieves values of roles with given names. |
void |
handleMBeanUnregistration |
Callback used by the Relation Service when a MBean referenced in a role is unregistered. |
Boolean |
isInRelationService() |
Returns an internal flag specifying if the object is still handled by the Relation Service. |
void |
postDeregister() |
Allows the MBean to perform any operations needed after having been unregistered in the MBean server. |
void |
postRegister |
Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed. |
void |
preDeregister() |
Allows the MBean to perform any operations it needs before being unregistered by the MBean server. |
ObjectName |
preRegister |
Allows the MBean to perform any operations it needs before being registered in the MBean Server. |
RoleList |
retrieveAllRoles() |
Returns all roles in the relation without checking read mode. |
void |
setRelationServiceManagementFlag |
Specifies whether this relation is handled by the Relation Service. |
void |
setRole |
Sets the given role. |
RoleResult |
setRoles |
Sets the given roles. |
public RelationSupport(String relationId, ObjectName relationServiceName, String relationTypeName, RoleList list) throws InvalidRoleValueException, IllegalArgumentException
RelationSupport
object. This constructor has to be used when the RelationSupport object will be registered as a MBean by the user, or when creating a user relation MBean whose class extends RelationSupport.
Nothing is done at the Relation Service level, i.e. the RelationSupport
object is not added to the RelationService
and no checks are performed to see if the provided values are correct. The object is always created, EXCEPT if:
- any of the required parameters is null
.
- the same name is used for two roles.
To be handled as a relation, the RelationSupport
object has to be added to the Relation Service using the Relation Service method addRelation().
relationId
- relation identifier, to identify the relation in the Relation Service. Expected to be unique in the given Relation Service.
relationServiceName
- ObjectName of the Relation Service where the relation will be registered. This parameter is required as it is the Relation Service that is aware of the definition of the relation type of the given relation, so that will be able to check update operations (set).
relationTypeName
- Name of relation type. Expected to have been created in the given Relation Service.
list
- list of roles (Role objects) to initialize the relation. Can be null
. Expected to conform to relation info in associated relation type.
InvalidRoleValueException
- if the same name is used for two roles.IllegalArgumentException
- if any of the required parameters (relation id, relation service ObjectName, or relation type name) is null
.public RelationSupport(String relationId, ObjectName relationServiceName, MBeanServer relationServiceMBeanServer, String relationTypeName, RoleList list) throws InvalidRoleValueException, IllegalArgumentException
RelationSupport
object. This constructor has to be used when the user relation MBean implements the interfaces expected to be supported by a relation by delegating to a RelationSupport object.
This object needs to know the Relation Service expected to handle the relation. So it has to know the MBean Server where the Relation Service is registered.
According to a limitation, a relation MBean must be registered in the same MBean Server as the Relation Service expected to handle it. So the user relation MBean has to be created and registered, and then the wrapped RelationSupport object can be created within the identified MBean Server.
Nothing is done at the Relation Service level, i.e. the RelationSupport
object is not added to the RelationService
and no checks are performed to see if the provided values are correct. The object is always created, EXCEPT if:
- any of the required parameters is null
.
- the same name is used for two roles.
To be handled as a relation, the RelationSupport
object has to be added to the Relation Service using the Relation Service method addRelation().
relationId
- relation identifier, to identify the relation in the Relation Service. Expected to be unique in the given Relation Service.
relationServiceName
- ObjectName of the Relation Service where the relation will be registered. This parameter is required as it is the Relation Service that is aware of the definition of the relation type of the given relation, so that will be able to check update operations (set).
relationServiceMBeanServer
- MBean Server where the wrapping MBean is or will be registered. Expected to be the MBean Server where the Relation Service is or will be registered.
relationTypeName
- Name of relation type. Expected to have been created in the given Relation Service.
list
- list of roles (Role objects) to initialize the relation. Can be null
. Expected to conform to relation info in associated relation type.
InvalidRoleValueException
- if the same name is used for two roles.IllegalArgumentException
- if any of the required parameters (relation id, relation service ObjectName, relation service MBeanServer, or relation type name) is null
.public List<ObjectName> getRole(String roleName) throws IllegalArgumentException, RoleNotFoundException, RelationServiceNotRegisteredException
Checks if the role exists and is readable according to the relation type.
getRole
in interface Relation
roleName
- name of roleIllegalArgumentException
- if null role nameRoleNotFoundException
- if: - there is no role with given name
- the role is not readable.
RelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean Serverpublic RoleResult getRoles(String[] roleNameArray) throws IllegalArgumentException, RelationServiceNotRegisteredException
Checks for each role if it exists and is readable according to the relation type.
getRoles
in interface Relation
roleNameArray
- array of names of roles to be retrievedIllegalArgumentException
- if null role nameRelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean Serverpublic RoleResult getAllRoles() throws RelationServiceNotRegisteredException
getAllRoles
in interface Relation
RelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean Serverpublic RoleList retrieveAllRoles()
retrieveAllRoles
in interface Relation
public Integer getRoleCardinality(String roleName) throws IllegalArgumentException, RoleNotFoundException
getRoleCardinality
in interface Relation
roleName
- name of roleIllegalArgumentException
- if null role nameRoleNotFoundException
- if there is no role with given namepublic void setRole(Role role) throws IllegalArgumentException, RoleNotFoundException, RelationTypeNotFoundException, InvalidRoleValueException, RelationServiceNotRegisteredException, RelationNotFoundException
Will check the role according to its corresponding role definition provided in relation's relation type
Will send a notification (RelationNotification with type RELATION_BASIC_UPDATE or RELATION_MBEAN_UPDATE, depending if the relation is a MBean or not).
setRole
in interface Relation
role
- role to be set (name and new value)IllegalArgumentException
- if null roleRoleNotFoundException
- if there is no role with the supplied role's name or if the role is not writable (no test on the write access mode performed when initializing the role)InvalidRoleValueException
- if value provided for role is not valid, i.e.: - the number of referenced MBeans in given value is less than expected minimum degree
- the number of referenced MBeans in provided value exceeds expected maximum degree
- one referenced MBean in the value is not an Object of the MBean class expected for that role
- a MBean provided for that role does not exist
RelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean ServerRelationTypeNotFoundException
- if the relation type has not been declared in the Relation ServiceRelationNotFoundException
- if the relation has not been added in the Relation Service.public RoleResult setRoles(RoleList list) throws IllegalArgumentException, RelationServiceNotRegisteredException, RelationTypeNotFoundException, RelationNotFoundException
Will check the role according to its corresponding role definition provided in relation's relation type
Will send one notification (RelationNotification with type RELATION_BASIC_UPDATE or RELATION_MBEAN_UPDATE, depending if the relation is a MBean or not) per updated role.
setRoles
in interface Relation
list
- list of roles to be setIllegalArgumentException
- if null role listRelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean ServerRelationTypeNotFoundException
- if the relation type has not been declared in the Relation Service.RelationNotFoundException
- if the relation MBean has not been added in the Relation Service.public void handleMBeanUnregistration(ObjectName objectName, String roleName) throws IllegalArgumentException, RoleNotFoundException, InvalidRoleValueException, RelationServiceNotRegisteredException, RelationTypeNotFoundException, RelationNotFoundException
The Relation Service will call this method to let the relation take action to reflect the impact of such unregistration.
BEWARE. the user is not expected to call this method.
Current implementation is to set the role with its current value (list of ObjectNames of referenced MBeans) without the unregistered one.
handleMBeanUnregistration
in interface Relation
objectName
- ObjectName of unregistered MBeanroleName
- name of role where the MBean is referencedIllegalArgumentException
- if null parameterRoleNotFoundException
- if role does not exist in the relation or is not writableInvalidRoleValueException
- if role value does not conform to the associated role info (this will never happen when called from the Relation Service)RelationServiceNotRegisteredException
- if the Relation Service is not registered in the MBean ServerRelationTypeNotFoundException
- if the relation type has not been declared in the Relation Service.RelationNotFoundException
- if this method is called for a relation MBean not added in the Relation Service.public Map<ObjectName,List<String>> getReferencedMBeans()
getReferencedMBeans
in interface Relation
ObjectName -> ArrayList of String (role names)
public String getRelationTypeName()
getRelationTypeName
in interface Relation
public ObjectName getRelationServiceName()
getRelationServiceName
in interface Relation
public String getRelationId()
getRelationId
in interface Relation
public ObjectName preRegister(MBeanServer server, ObjectName name) throws Exception
MBeanRegistration
preRegister
in interface MBeanRegistration
server
- The MBean Server in which the MBean will be registered.name
- The object name of the MBean. This name is null if the name parameter to one of the createMBean
or registerMBean
methods in the MBeanServer
interface is null. In that case, this method must return a non-null ObjectName for the new MBean.name
parameter is not null, it will usually but not necessarily be the returned value.Exception
- This exception will be caught by the MBean Server and re-thrown as an MBeanRegistrationException
.public void postRegister(Boolean registrationDone)
MBeanRegistration
If the implementation of this method throws a RuntimeException
or an Error
, the MBean Server will rethrow those inside a RuntimeMBeanException
or RuntimeErrorException
, respectively. However, throwing an exception in postRegister
will not change the state of the MBean: if the MBean was already registered (registrationDone
is true
), the MBean will remain registered.
This might be confusing for the code calling createMBean()
or registerMBean()
, as such code might assume that MBean registration has failed when such an exception is raised. Therefore it is recommended that implementations of postRegister
do not throw Runtime Exceptions or Errors if it can be avoided.
postRegister
in interface MBeanRegistration
registrationDone
- Indicates whether or not the MBean has been successfully registered in the MBean server. The value false means that the registration phase has failed.public void preDeregister() throws Exception
MBeanRegistration
preDeregister
in interface MBeanRegistration
Exception
- This exception will be caught by the MBean server and re-thrown as an MBeanRegistrationException
.public void postDeregister()
MBeanRegistration
If the implementation of this method throws a RuntimeException
or an Error
, the MBean Server will rethrow those inside a RuntimeMBeanException
or RuntimeErrorException
, respectively. However, throwing an exception in postDeregister
will not change the state of the MBean: the MBean was already successfully deregistered and will remain so.
This might be confusing for the code calling unregisterMBean()
, as it might assume that MBean deregistration has failed. Therefore it is recommended that implementations of postDeregister
do not throw Runtime Exceptions or Errors if it can be avoided.
postDeregister
in interface MBeanRegistration
public Boolean isInRelationService()
isInRelationService
in interface RelationSupportMBean
Boolean.TRUE
if the object is still handled by the Relation Service and Boolean.FALSE
otherwise.public void setRelationServiceManagementFlag(Boolean flag) throws IllegalArgumentException
RelationSupportMBean
Specifies whether this relation is handled by the Relation Service.
BEWARE, this method has to be exposed as the Relation Service will access the relation through its management interface. It is RECOMMENDED NOT to use this method. Using it does not affect the registration of the relation object in the Relation Service, but will provide wrong information about it!
setRelationServiceManagementFlag
in interface RelationSupportMBean
flag
- whether the relation is handled by the Relation Service.IllegalArgumentException
- if null parameter
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