/*
 * 
 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * The contents of this file are subject to the Sun Community Source
 * License v3.0/Jini Technology Specific Attachment v 1.0 (the
 * "License"). You may not use this file except in compliance with the
 * License. You may obtain a copy of the License at
 * http://wwws.sun.com/software/jini/licensing/SCSL3_JiniTSA1.html.
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 * 
 * The Reference Code is Jini Technology Core Platform code, v2.0. The
 * Developer of the Reference Code is Sun Microsystems, Inc.
 * 
 * Contributor(s): Sun Microsystems, Inc.
 * 
 * The contents of this file comply with the Jini Technology Core
 * Platform Compatibility Kit, v2.0A.
 * 
 * Tester(s): Sun Microsystems, Inc.
 * 
 * Test Platform(s):
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Solaris(TM)SPARC/x86
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Linux (Intel x86)
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Windows (Intel Platform)
 * 
 */

package net.jini.io;

import java.util.Collection;

/**
 * Provides a collection of context information objects that are
 * associated with an {@link java.io.ObjectOutputStream} or {@link
 * java.io.ObjectInputStream} instance that implements this interface.
 *
 * <p>The class of an object that is being serialized or deserialized
 * can test (in its private
 * <code>writeObject(ObjectOutputStream)</code> or
 * <code>readObject(ObjectInputStream)</code> method) if the object
 * stream being used implements this interface.  If the stream does
 * implement this interface, the class can then retrieve context
 * information relevant to the overall serialization or
 * deserialization operation by invoking the {@link
 * #getObjectStreamContext getObjectStreamContext} method and
 * inspecting the elements of the returned collection.
 *
 * <p>The contents of the collection are determined by the
 * implementation of the object stream.  The context information
 * available from a given element of the collection is determined by
 * that element's type.
 *
 * Examples of types that a context object might implement include
 * {@link net.jini.io.context.ClientHost} and
 * {@link net.jini.io.context.ClientSubject}.
 *
 * @author	Sun Microsystems, Inc.
 * @since 2.0
 */
public interface ObjectStreamContext {

    /**
     * Returns this object stream's collection of context information
     * objects.  
     *
     * <p>The context information available from a given element of
     * the collection is determined by that element's type.  The order
     * of the elements is insignificant.  The collection may be empty.
     *
     * <p>The caller of this method cannot assume that the returned
     * collection is modifiable.
     *
     * @return	a collection of this stream's context objects
     */
    Collection getObjectStreamContext();
}
