public class

RelationSupport

extends Object
implements MBeanRegistration RelationSupportMBean
java.lang.Object
   ↳ javax.management.relation.RelationSupport

Class Overview

A RelationSupport object is used internally by the Relation Service to represent simple relations (only roles, no properties or methods), with an unlimited number of roles, of any relation type. As internal representation, it is not exposed to the user.

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.

Summary

Public Constructors
RelationSupport(String relationId, ObjectName relationServiceName, String relationTypeName, RoleList list)
Creates a RelationSupport object.
RelationSupport(String relationId, ObjectName relationServiceName, MBeanServer relationServiceMBeanServer, String relationTypeName, RoleList list)
Creates a RelationSupport object.
Public Methods
RoleResult getAllRoles()
Returns all roles present in the relation.
Map<ObjectName, List<String>> 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<ObjectName> getRole(String roleName)
Retrieves role value for given role name.
Integer getRoleCardinality(String roleName)
Returns the number of MBeans currently referenced in the given role.
RoleResult getRoles(String[] roleNameArray)
Retrieves values of roles with given names.
void handleMBeanUnregistration(ObjectName objectName, String roleName)
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(Boolean registrationDone)
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(MBeanServer server, ObjectName name)
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(Boolean flag)

Specifies whether this relation is handled by the Relation Service.

void setRole(Role role)
Sets the given role.
RoleResult setRoles(RoleList list)
Sets the given roles.
[Expand]
Inherited Methods
From class java.lang.Object
From interface javax.management.MBeanRegistration
From interface javax.management.relation.Relation
From interface javax.management.relation.RelationSupportMBean

Public Constructors

public RelationSupport (String relationId, ObjectName relationServiceName, String relationTypeName, RoleList list)

Creates a 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().

Parameters
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.
Throws
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)

Creates a 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().

Parameters
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.
Throws
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 Methods

public RoleResult getAllRoles ()

Returns all roles present in the relation.

Returns
  • a RoleResult object, including a RoleList (for roles successfully retrieved) and a RoleUnresolvedList (for roles not readable).
Throws
RelationServiceNotRegisteredException if the Relation Service is not registered in the MBean Server

public Map<ObjectName, List<String>> getReferencedMBeans ()

Retrieves MBeans referenced in the various roles of the relation.

Returns
  • a HashMap mapping:

    ObjectName -> ArrayList of String (role names)

public String getRelationId ()

Returns relation identifier (used to uniquely identify the relation inside the Relation Service).

Returns
  • the relation id.

public ObjectName getRelationServiceName ()

Returns ObjectName of the Relation Service handling the relation.

Returns
  • the ObjectName of the Relation Service.

public String getRelationTypeName ()

Returns name of associated relation type.

Returns
  • the name of the relation type.

public List<ObjectName> getRole (String roleName)

Retrieves role value for given role name.

Checks if the role exists and is readable according to the relation type.

Parameters
roleName name of role
Returns
  • the ArrayList of ObjectName objects being the role value
Throws
IllegalArgumentException if null role name
RoleNotFoundException if:

- there is no role with given name

- the role is not readable.
RelationServiceNotRegisteredException if the Relation Service is not registered in the MBean Server
See Also

public Integer getRoleCardinality (String roleName)

Returns the number of MBeans currently referenced in the given role.

Parameters
roleName name of role
Returns
  • the number of currently referenced MBeans in that role
Throws
IllegalArgumentException if null role name
RoleNotFoundException if there is no role with given name

public RoleResult getRoles (String[] roleNameArray)

Retrieves values of roles with given names.

Checks for each role if it exists and is readable according to the relation type.

Parameters
roleNameArray array of names of roles to be retrieved
Returns
  • a RoleResult object, including a RoleList (for roles successfully retrieved) and a RoleUnresolvedList (for roles not retrieved).
Throws
IllegalArgumentException if null role name
RelationServiceNotRegisteredException if the Relation Service is not registered in the MBean Server
See Also

public void handleMBeanUnregistration (ObjectName objectName, String roleName)

Callback used by the Relation Service when a MBean referenced in a role is unregistered.

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.

Parameters
objectName ObjectName of unregistered MBean
roleName name of role where the MBean is referenced
Throws
IllegalArgumentException if null parameter
RoleNotFoundException if role does not exist in the relation or is not writable
InvalidRoleValueException 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 Server
RelationTypeNotFoundException 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 Boolean isInRelationService ()

Returns an internal flag specifying if the object is still handled by the Relation Service.

Returns
  • a Boolean equal to TRUE if the object is still handled by the Relation Service and FALSE otherwise.

public void postDeregister ()

Allows the MBean to perform any operations needed after having been unregistered in the MBean server.

public void postRegister (Boolean registrationDone)

Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.

Parameters
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 ()

Allows the MBean to perform any operations it needs before being unregistered by the MBean server.

Throws
Exception

public ObjectName preRegister (MBeanServer server, ObjectName name)

Allows the MBean to perform any operations it needs before being registered in the MBean server. If the name of the MBean is not specified, the MBean can provide a name for its registration. If any exception is raised, the MBean will not be registered in the MBean server.

Parameters
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.
Returns
  • The name under which the MBean is to be registered. This value must not be null. If the name parameter is not null, it will usually but not necessarily be the returned value.
Throws
Exception

public RoleList retrieveAllRoles ()

Returns all roles in the relation without checking read mode.

Returns
  • a RoleList

public void setRelationServiceManagementFlag (Boolean flag)

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!

Parameters
flag whether the relation is handled by the Relation Service.
Throws
IllegalArgumentException

public void setRole (Role role)

Sets the given role.

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).

Parameters
role role to be set (name and new value)
Throws
IllegalArgumentException if null role
RoleNotFoundException 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 Server
RelationTypeNotFoundException if the relation type has not been declared in the Relation Service
RelationNotFoundException if the relation has not been added in the Relation Service.
See Also

public RoleResult setRoles (RoleList list)

Sets the given roles.

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.

Parameters
list list of roles to be set
Returns
  • a RoleResult object, including a RoleList (for roles successfully set) and a RoleUnresolvedList (for roles not set).
Throws
IllegalArgumentException if null role list
RelationServiceNotRegisteredException if the Relation Service is not registered in the MBean Server
RelationTypeNotFoundException 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.
See Also