org.jdiameter.api
Interface Wrapper

All Known Subinterfaces:

Answer, Avp, AvpSet, Message, MetaData, MutablePeerTable, Network, PeerTable, RawSession, RealmTable, Request, Session, Stack

public interface Wrapper

Interface for JDiameter classes which provide the ability to retrieve the delegate instance when the instance in question is in fact a proxy class. The wrapper pattern is employed by many JDiameter stack implementations to provide extensions beyond the traditional JDiameter API that are specific to a data source. Developers may wish to gain access to these resources that are wrapped ( the delegates) as proxy class instances representing the the actual resources. This interface describes a standard mechanism to access these wrapped resources represented by their proxy, to permit direct access to the resource delegates.

Version:

1.5.1 Final

Author:

erick.svenson@yahoo.com, artem.litvinov@gmail.com

Method Summary

boolean	isWrapperFor(java.lang.Class<?> iface) Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.
<T> T	unwrap(java.lang.Class<T> iface) Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.

Method Detail

isWrapperFor

boolean isWrapperFor(java.lang.Class<?> iface)
                     throws InternalException

Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does. Returns false otherwise. If this implements the interface then return true, else if t his is a wrapper then return the result of recursively calling isWrapperFor on the wrapped object. If this does not implement the interface and is not a wrapper, return false. This method should be implemented as a low-cost operation compared to unwrap so that callers can use this method to avoid expensive unwrap calls that may fail. If this method returns true then calling unwrap with the same argument should succeed.

Parameters:

iface - A Class defining an interface that the result must implement.

Returns:

true if this implements the interface or directly or indirectly wraps an object that does.

Throws:

InternalException - If no object found that implements the interface

unwrap

<T> T unwrap(java.lang.Class<T> iface)
         throws InternalException

Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy. The result may be either the object found to implement the interface or a proxy for that object. If the receiver implements the interface then that is the object. If the receiver is a wrapper and the wrapped object implements the interface then that is the object. Otherwise the object is the result of calling unwrap recursively on the wrapped object. If the receiver is not a wrapper and does not implement the interface, then an SQLException is thrown.

Parameters:

iface - A Class defining an interface that the result must implement.

Returns:

an object that implements the interface. May be a proxy for the actual implementing object.

Throws:

InternalException - If no object found that implements the interface