Class RelationSupport

java.lang.Object
- javax.management.relation.RelationSupport

All Implemented Interfaces:: MBeanRegistration, Relation, RelationSupportMBean

public class RelationSupport
extends Object
implements RelationSupportMBean, MBeanRegistration

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.

Since:: 1.5

Constructor Summary

Constructors
Constructor	Description
`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.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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.
`RoleList`	`retrieveAllRoles()`	Returns all roles in the relation without checking read mode.
`void`	`setRole(Role role)`	Sets the given role.
`RoleResult`	`setRoles(RoleList list)`	Sets the given roles.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods declared in interface javax.management.MBeanRegistration

postDeregister, postRegister, preDeregister, preRegister

Methods declared in interface javax.management.relation.RelationSupportMBean

setRelationServiceManagementFlag

Constructor Detail

RelationSupport

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

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.

RelationSupport

public RelationSupport(String relationId,
                       ObjectName relationServiceName,
                       MBeanServer relationServiceMBeanServer,
                       String relationTypeName,
                       RoleList list)
                throws InvalidRoleValueException,
                       IllegalArgumentException

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.

Method Detail

getRole

public List<ObjectName> getRole(String roleName)
                         throws IllegalArgumentException,
                                RoleNotFoundException,
                                RelationServiceNotRegisteredException

Retrieves role value for given role name.

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

Specified by:

getRole in interface Relation

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

getRoles

public RoleResult getRoles(String[] roleNameArray)
                    throws IllegalArgumentException,
                           RelationServiceNotRegisteredException

Retrieves values of roles with given names.

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

Specified by:: getRoles in interface Relation
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:: setRoles(javax.management.relation.RoleList)

getAllRoles

public RoleResult getAllRoles()
                       throws RelationServiceNotRegisteredException

Returns all roles present in the relation.

Specified by:: getAllRoles in interface 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

retrieveAllRoles

public RoleList retrieveAllRoles()

Returns all roles in the relation without checking read mode.

Specified by:: retrieveAllRoles in interface Relation
Returns:: a RoleList

getRoleCardinality

public Integer getRoleCardinality(String roleName)
                           throws IllegalArgumentException,
                                  RoleNotFoundException

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

Specified by:: getRoleCardinality in interface Relation
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

setRole

public void setRole(Role role)
             throws IllegalArgumentException,
                    RoleNotFoundException,
                    RelationTypeNotFoundException,
                    InvalidRoleValueException,
                    RelationServiceNotRegisteredException,
                    RelationNotFoundException

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).

Specified by:

setRole in interface Relation

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:

getRole(java.lang.String)

setRoles

public RoleResult setRoles(RoleList list)
                    throws IllegalArgumentException,
                           RelationServiceNotRegisteredException,
                           RelationTypeNotFoundException,
                           RelationNotFoundException

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.

Specified by:: setRoles in interface Relation
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:: getRoles(java.lang.String[])

handleMBeanUnregistration

public void handleMBeanUnregistration(ObjectName objectName,
                                      String roleName)
                               throws IllegalArgumentException,
                                      RoleNotFoundException,
                                      InvalidRoleValueException,
                                      RelationServiceNotRegisteredException,
                                      RelationTypeNotFoundException,
                                      RelationNotFoundException

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.

Specified by:: handleMBeanUnregistration in interface Relation
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.

getReferencedMBeans

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

Retrieves MBeans referenced in the various roles of the relation.

Specified by:: getReferencedMBeans in interface Relation
Returns:: a HashMap mapping:
ObjectName -> ArrayList of String (role names)

getRelationTypeName

public String getRelationTypeName()

Returns name of associated relation type.

Specified by:: getRelationTypeName in interface Relation
Returns:: the name of the relation type.

getRelationServiceName

public ObjectName getRelationServiceName()

Returns ObjectName of the Relation Service handling the relation.

Specified by:: getRelationServiceName in interface Relation
Returns:: the ObjectName of the Relation Service.

getRelationId

public String getRelationId()

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

Specified by:: getRelationId in interface Relation
Returns:: the relation id.

isInRelationService

public Boolean isInRelationService()

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

Specified by:: isInRelationService in interface RelationSupportMBean
Returns:: a Boolean equal to Boolean.TRUE if the object is still handled by the Relation Service and Boolean.FALSE otherwise.