com.esotericsoftware.kryonet.rmi

Class ObjectSpace

java.lang.Object

com.esotericsoftware.kryonet.rmi.ObjectSpace

public class ObjectSpace
extends Object

Allows methods on objects to be invoked remotely over TCP. Objects are registered with an ID. The remote end of connections that have been added are allowed to access registered objects.

It costs at least 2 bytes more to use remote method invocation than just sending the parameters. If the method has a return value which is not ignored, an extra byte is written. If the type of a parameter is not final (note primitives are final) then an extra byte is written for that parameter.

Author:

Nathan Sweet

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ObjectSpace.InvokeMethod Internal message to invoke methods remotely.
static class	ObjectSpace.InvokeMethodResult Internal message to return the result of a remotely invoked method.
static class	ObjectSpace.RemoteObjectSerializer Serializes an object registered with an ObjectSpace so the receiving side gets a RemoteObject proxy rather than the bytes for the serialized object.

Constructor Summary

Constructors

Constructor and Description
ObjectSpace() Creates an ObjectSpace with no connections.
ObjectSpace(Connection connection) Creates an ObjectSpace with the specified connection.

Method Summary

Methods

Modifier and Type	Method and Description
void	addConnection(Connection connection) Allows the remote end of the specified connection to access objects registered in this ObjectSpace.
void	close() Causes this ObjectSpace to stop listening to the connections for method invocation messages.
static RemoteObject	getRemoteObject(Connection connection, int objectID, Class... ifaces) Returns a proxy object that implements the specified interfaces.
static <T> T	getRemoteObject(Connection connection, int objectID, Class<T> iface) Identical to getRemoteObject(Connection, int, Class...) except returns the object cast to the specified interface type.
protected void	invoke(Connection connection, Object target, ObjectSpace.InvokeMethod invokeMethod) Invokes the method on the object and, if necessary, sends the result back to the connection that made the invocation request.
void	register(int objectID, Object object) Registers an object to allow the remote end of the ObjectSpace's connections to access it using the specified ID.
static void	registerClasses(com.esotericsoftware.kryo.Kryo kryo) Registers the classes needed to use ObjectSpaces.
void	remove(int objectID) Removes an object.
void	remove(Object object) Removes an object.
void	removeConnection(Connection connection) Removes the specified connection, it will no longer be able to access objects registered in this ObjectSpace.
void	setExecutor(Executor executor) Sets the executor used to invoke methods when an invocation is received from a remote endpoint.

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectSpace

public ObjectSpace()

Creates an ObjectSpace with no connections. Connections must be added to allow the remote end of the connections to access objects in this ObjectSpace.

ObjectSpace

public ObjectSpace(Connection connection)

Creates an ObjectSpace with the specified connection. More connections can be added.

Method Detail

setExecutor

public void setExecutor(Executor executor)

Sets the executor used to invoke methods when an invocation is received from a remote endpoint. By default, no executor is set and invocations occur on the network thread, which should not be blocked for long.

Parameters:

executor - May be null.

register

public void register(int objectID,
            Object object)

Registers an object to allow the remote end of the ObjectSpace's connections to access it using the specified ID.

If a connection is added to multiple ObjectSpaces, the same object ID should not be registered in more than one of those ObjectSpaces.

Parameters:

objectID - Must not be Integer.MAX_VALUE.

See Also:

getRemoteObject(Connection, int, Class...)

remove

public void remove(int objectID)

Removes an object. The remote end of the ObjectSpace's connections will no longer be able to access it.

remove

public void remove(Object object)

Removes an object. The remote end of the ObjectSpace's connections will no longer be able to access it.

close

public void close()

Causes this ObjectSpace to stop listening to the connections for method invocation messages.

addConnection

public void addConnection(Connection connection)

Allows the remote end of the specified connection to access objects registered in this ObjectSpace.

removeConnection

public void removeConnection(Connection connection)

Removes the specified connection, it will no longer be able to access objects registered in this ObjectSpace.

invoke

protected void invoke(Connection connection,
          Object target,
          ObjectSpace.InvokeMethod invokeMethod)

Invokes the method on the object and, if necessary, sends the result back to the connection that made the invocation request. This method is invoked on the update thread of the EndPoint for this ObjectSpace and unless an executor has been set.

Parameters:

connection - The remote side of this connection requested the invocation.

getRemoteObject

public static <T> T getRemoteObject(Connection connection,
                    int objectID,
                    Class<T> iface)

Identical to getRemoteObject(Connection, int, Class...) except returns the object cast to the specified interface type. The returned object still implements RemoteObject.

getRemoteObject

public static RemoteObject getRemoteObject(Connection connection,
                           int objectID,
                           Class... ifaces)

Returns a proxy object that implements the specified interfaces. Methods invoked on the proxy object will be invoked remotely on the object with the specified ID in the ObjectSpace for the specified connection. If the remote end of the connection has not added the connection to the ObjectSpace, the remote method invocations will be ignored.

Methods that return a value will throw TimeoutException if the response is not received with the response timeout.

If non-blocking is false (the default), then methods that return a value must not be called from the update thread for the connection. An exception will be thrown if this occurs. Methods with a void return value can be called on the update thread.

If a proxy returned from this method is part of an object graph sent over the network, the object graph on the receiving side will have the proxy object replaced with the registered object.

See Also:

RemoteObject

registerClasses

public static void registerClasses(com.esotericsoftware.kryo.Kryo kryo)

Registers the classes needed to use ObjectSpaces. This should be called before any connections are opened.

See Also:

Kryo.register(Class, Serializer)