com.threerings.io.Streamable Maven / Gradle / Ivy
//
// $Id$
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2012 Three Rings Design, Inc., All Rights Reserved
// http://code.google.com/p/narya/
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package com.threerings.io;
/**
* Marks an object as streamable, meaning that it can be written to {@link ObjectOutputStream}
* instances and read from {@link ObjectInputStream} instances.
*
* All non-{@code transient}, non-{@link NotStreamable} fields will be automatically written
* and restored for a {@link Streamable} instance. Classes that wish to stream transient fields or
* customize the streaming process should implement methods with the following signatures:
*
*
* public void writeObject ({@link ObjectOutputStream} out);
* public void readObject ({@link ObjectInputStream} in);
*
*
* They can then handle the entirety of the streaming process, or call {@link
* ObjectOutputStream#defaultWriteObject} and {@link ObjectInputStream#defaultReadObject} from
* within their {@code writeObject} and {@code readObject} methods to perform the standard
* streaming in addition to their customized behavior.
*
* Streamable classes must either have a zero-argument constructor, in which case any
* number of other constructors are allowed, but the zero-argument constructor will be used when
* unserializing an instance; or they must have exactly one non-zero-argument constructor, and that
* constructor will be called when unserializing an instance with "zero/null" values (meaning all
* primitive types will be passed the appropriate zero value, and all reference types will be
* passed null. This latter approach can even be used by classes with final fields, as the
* zero/null values will be overwritten during unstreaming.
*/
public interface Streamable
{
/**
* A marker interface for streamable classes that expect to be extended anonymously, but for
* which the implicit outer class reference can (and should) be ignored. This allows one to
* package up units of code and ship them between peers, or even between client and server.
*/
public interface Closure extends Streamable {}
}