KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > sleepycat > bind > serial > ClassCatalog


1 /*-
2  * See the file LICENSE for redistribution information.
3  *
4  * Copyright (c) 2000,2006 Oracle. All rights reserved.
5  *
6  * $Id: ClassCatalog.java,v 1.18 2006/10/30 21:14:07 bostic Exp $
7  */
8
9 package com.sleepycat.bind.serial;
10
11 import java.io.ObjectStreamClass JavaDoc;
12
13 import com.sleepycat.je.DatabaseException;
14
15 /**
16  * A catalog of class description information for use during object
17  * serialization.
18  *
19  * <p>A catalog is used to store class descriptions separately from serialized
20  * objects, to avoid redundantly stored information with each object.
21  * When serialized objects are stored in a database, a {@link
22  * StoredClassCatalog} should be used.</p>
23  *
24  * <p>This information is used for serialization of class descriptors or
25  * java.io.ObjectStreamClass objects, each of which represents a unique class
26  * format. For each unique format, a unique class ID is assigned by the
27  * catalog. The class ID can then be used in the serialization stream in place
28  * of the full class information. When used with {@link SerialInput} and
29  * {@link SerialOutput} or any of the serial bindings, the use of the catalog
30  * is transparent to the application.</p>
31  *
32  * @author Mark Hayes
33  */
34 public interface ClassCatalog {
35
36     /**
37      * Close a catalog database and release any cached resources.
38      */
39     public void close()
40         throws DatabaseException;
41
42     /**
43      * Return the class ID for the current version of the given class
44      * description.
45      * This is used for storing in serialization streams in place of a full
46      * class descriptor, since it is much more compact. To get back the
47      * ObjectStreamClass for a class ID, call {@link #getClassFormat(byte[])}.
48      * This function causes a new class ID to be assigned if the class
49      * description has changed.
50      *
51      * @param classDesc The class description for which to return the
52      * class ID.
53      *
54      * @return The class ID for the current version of the class.
55      */
56     public byte[] getClassID(ObjectStreamClass JavaDoc classDesc)
57         throws DatabaseException, ClassNotFoundException JavaDoc;
58
59     /**
60      * Return the ObjectStreamClass for the given class ID. This may or may
61      * not be the current class format, depending on whether the class has
62      * changed since the class ID was generated.
63      *
64      * @param classID The class ID for which to return the class format.
65      *
66      * @return The class format for the given class ID, which may or may not
67      * represent the current version of the class.
68      */
69     public ObjectStreamClass JavaDoc getClassFormat(byte[] classID)
70         throws DatabaseException, ClassNotFoundException JavaDoc;
71 }
72
Popular Tags