/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.yangtools.concepts; /** * Immutable Object - object does not change its state during lifecycle. * *
* Marker interface for objects which are immutable. This interface should be * used directly on objects, preferably final, which are eligible for the * JSR-305 @Immutable annotation and objects implementing this interface are * required to abide to interface contract specified by @Immutable. * *
The reason for the existence of this interface is twofold:
* unlike @Immutable, it is
* visible at runtime and objects can be quickly checked for compliance using a
* quick 'instanceof' check. This is useful for code which needs to capture a
* point-in-time snapshot of otherwise unknown objects -- a typical example
* being logging/tracing systems. Such systems would normally have to rely on
* serializing the object to get a stable checkpoint. Objects marked with this
* interface are guaranteed to remain stable, thus already being a checkpoint
* for all intents and purposes, so aside from retaining a reference no further
* action on them is necessary.
*
* Implementations of this interface must not change any public state during
* their whole lifecycle.
*
* This interface is mutually exclusive with {@link Mutable} and other
* {@link MutationBehaviour}s.
*
* @author Robert Varga