01: /* Copyright (C) 2004 - 2007 db4objects Inc. http://www.db4o.com
02:
03: This file is part of the db4o open source object database.
04:
05: db4o is free software; you can redistribute it and/or modify it under
06: the terms of version 2 of the GNU General Public License as published
07: by the Free Software Foundation and as clarified by db4objects' GPL
08: interpretation policy, available at
09: http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10: Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11: Suite 350, San Mateo, CA 94403, USA.
12:
13: db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14: WARRANTY; without even the implied warranty of MERCHANTABILITY or
15: FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16: for more details.
17:
18: You should have received a copy of the GNU General Public License along
19: with this program; if not, write to the Free Software Foundation, Inc.,
20: 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21: package com.db4o.config;
22:
23: import com.db4o.*;
24:
25: /**
26: * translator interface to translate objects on storage and activation.
27: * <br><br>
28: * By writing classes that implement this interface, it is possible to
29: * define how application classes are to be converted to be stored more efficiently.
30: * <br><br>
31: * Before starting a db4o session, translator classes need to be registered. An example:<br>
32: * <code>
33: * Configuration config = Db4o.configure();<br>
34: * ObjectClass oc = config.objectClass("package.className");<br>
35: * oc.translate(new FooTranslator());</code><br><br>
36: *
37: */
38: public interface ObjectTranslator {
39:
40: /**
41: * db4o calls this method during storage and query evaluation.
42: * @param container the ObjectContainer used
43: * @param applicationObject the Object to be translated
44: * @return return the object to store.<br>It needs to be of the class
45: * {@link #storedClass storedClass()}.
46: */
47: public Object onStore(ObjectContainer container,
48: Object applicationObject);
49:
50: /**
51: * db4o calls this method during activation.
52: * @param container the ObjectContainer used
53: * @param applicationObject the object to set the members on
54: * @param storedObject the object that was stored
55: */
56: public void onActivate(ObjectContainer container,
57: Object applicationObject, Object storedObject);
58:
59: /**
60: * return the Class you are converting to.
61: * @return the Class of the object you are returning with the method
62: * {@link #onStore onStore()}
63: */
64: public Class storedClass();
65: }
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