info.pppc.base.system

Class ObjectRegistry

java.lang.Object

info.pppc.base.system.ObjectRegistry

public final class ObjectRegistry
extends java.lang.Object

A registry for local objects managed by the invocation broker. The object registry is synchronized, all calls to the registry can be performed without any additional synchronization.

Author:

Marcus Handte

Field Summary

Fields

Modifier and Type	Field and Description
static int	EVENT_KNOWN_ADDED The event constant that is used to signal that a previously unknown object with a well known object id has been registered at the object registry.
static int	EVENT_KNOWN_REMOVED The event constant that is used to signal that a previously registered object with a well known object id has been removed from the registry.
static int	EVENT_OBJECT_ADDED The event constant that is used to signal that a new local object has been registered at the object registry.
static int	EVENT_OBJECT_REMOVED The event constant that is used to signal that a previously registered object has been removed from the object registry.

Method Summary

Methods

Modifier and Type	Method and Description
void	addObjectListener(int type, IListener listener) Adds an object listener for the specified event types.
ObjectID	getIdentifier(IInvocationHandler handler) Retrieves the id of a previously registered invocation handler.
IInvocationHandler	getInvocationHandler(ObjectID id) Retrieves an invocation handler for the specified id.
ObjectID[]	getKnownIdentifiers() Returns the well known services registered at this registry.
java.lang.Object	getKnownReference(ObjectID id) Retrieves a local reference for the specified id.
boolean	isIdentifierRegistered(ObjectID id) Determines whether the specified object has been registered.
ObjectID	registerObject(IInvocationHandler handler) Registers a new object that handles invocations.
void	registerObject(ObjectID id, IInvocationHandler handler, java.lang.Object localReference) Registers a well known object with the specified id.
IInvocationHandler	removeObject(ObjectID id) Removes the invocation handler with the specified identifier.
boolean	removeObjectListener(int type, IListener listener) Removes a previously registered object listener from the set of listeners that are registered for the specified types.
java.lang.String	toString() Returns a string representation of the internal data structures of the object registry.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

EVENT_OBJECT_ADDED

public static final int EVENT_OBJECT_ADDED

The event constant that is used to signal that a new local object has been registered at the object registry. The user object of the event will carry the object id of the registered object. Note that this event will be fired for any object id (well-known or auto-generated).

See Also:

Constant Field Values

EVENT_OBJECT_REMOVED

public static final int EVENT_OBJECT_REMOVED

The event constant that is used to signal that a previously registered object has been removed from the object registry. The user object of the event will carry the object id of the unregistered object. Note that this event will be fired for any object id (well-known or auto-generated).

See Also:

Constant Field Values

EVENT_KNOWN_ADDED

public static final int EVENT_KNOWN_ADDED

The event constant that is used to signal that a previously unknown object with a well known object id has been registered at the object registry. The user object of the event will carry the object id of the registered object.

See Also:

Constant Field Values

EVENT_KNOWN_REMOVED

public static final int EVENT_KNOWN_REMOVED

The event constant that is used to signal that a previously registered object with a well known object id has been removed from the registry. The user object of the vent will carry the object id of the removed object.

See Also:

Constant Field Values

Method Detail

isIdentifierRegistered

public boolean isIdentifierRegistered(ObjectID id)

Determines whether the specified object has been registered.

Parameters:

id - The id of the object to lookup.

Returns:

True if it exists, false otherwise.

getInvocationHandler

public IInvocationHandler getInvocationHandler(ObjectID id)

Retrieves an invocation handler for the specified id.

Parameters:

id - The id of the object to lookup.

Returns:

An invocation handler if the id has been registered, otherwise null.

getIdentifier

public ObjectID getIdentifier(IInvocationHandler handler)

Retrieves the id of a previously registered invocation handler.

Parameters:

handler - The handler to lookup.

Returns:

The id of the invocation handler or null if the handler is no longer registered.

getKnownReference

public java.lang.Object getKnownReference(ObjectID id)

Retrieves a local reference for the specified id.

Parameters:

id - The id of the object to lookup.

Returns:

An invocation handler if a local reference for the id has been registered, otherwise null.

registerObject

public ObjectID registerObject(IInvocationHandler handler)

Registers a new object that handles invocations.

Parameters:

handler - The handler used to dispatch requests.

Returns:

The object id assigned to the object.

registerObject

public void registerObject(ObjectID id,
                  IInvocationHandler handler,
                  java.lang.Object localReference)

Registers a well known object with the specified id.

Parameters:

id - The id of the well known object.

handler - The handler for the object with the specified id.

localReference - The local reference for the well known object.

removeObject

public IInvocationHandler removeObject(ObjectID id)

Removes the invocation handler with the specified identifier.

Parameters:

id - The identifier of the invocation handler.

Returns:

The invocation handler that has been removed or null if the id is not registered.

getKnownIdentifiers

public ObjectID[] getKnownIdentifiers()

Returns the well known services registered at this registry.

Returns:

The identifiers of well known services that are available locally.

addObjectListener

public void addObjectListener(int type,
                     IListener listener)

Adds an object listener for the specified event types. At the present time, object listeners can be registered for EVENT_OBJECT_ADDED, EVENT_OBJECT_REMOVED, EVENT_KNOWN_REMOVED, EVENT_KNOWN_ADDED events. All events will carry the corresponding object id as user object.

Parameters:

type - The types of events to register. Multiple types can be concatenated using a logical or.

listener - The object listener to add.

removeObjectListener

public boolean removeObjectListener(int type,
                           IListener listener)

Removes a previously registered object listener from the set of listeners that are registered for the specified types.

Parameters:

type - The types of events to register. Multiple types can be concatenated using a logical or.

listener - The listener to remove.

Returns:

True if the listener is no longer registered for an event and thus it has been removed.

toString

public java.lang.String toString()

Returns a string representation of the internal data structures of the object registry.

Overrides:

toString in class java.lang.Object

Returns:

An internal string representation.