1 /**
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Intalio, Inc. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Intalio, Inc. Exolab is a registered
23 * trademark of Intalio, Inc.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
42 *
43 * $Id$
44 */
45
46 package org.exolab.castor.mapping;
47
48 /**
49 * A field handler knows how to perform various operations on the field that
50 * require access to the field value.
51 *
52 * @author <a href="arkin@intalio.com">Assaf Arkin</a>
53 * @version $Revision$ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar
54 * 2003) $
55 * @see FieldDescriptor
56 */
57 public interface FieldHandler<T> {
58
59 /**
60 * Returns the value of the field from the object.
61 *
62 * @param object
63 * The object
64 * @return The value of the field
65 * @throws IllegalStateException
66 * The Java object has changed and is no longer supported by this
67 * handler, or the handler is not compatible with the Java object
68 */
69 public T getValue(Object object) throws IllegalStateException;
70
71 /**
72 * Sets the value of the field on the object.
73 *
74 * @param object
75 * The object.
76 * @param value
77 * The new value.
78 * @throws IllegalStateException
79 * The Java object has changed and is no longer supported by this
80 * handler, or the handler is not compatible with the Java object.
81 * @throws IllegalArgumentException
82 * The value passed is not of a supported type.
83 */
84 public void setValue(Object object, T value) throws IllegalStateException, IllegalArgumentException;
85
86 /**
87 * Sets the value of the field to a default value.
88 * <p>
89 * Reference fields are set to null, primitive fields are set to their
90 * default value, collection fields are emptied of all elements.
91 *
92 * @param object
93 * The object.
94 * @throws IllegalStateException
95 * The Java object has changed and is no longer supported by this
96 * handler, or the handler is not compatible with the Java object.
97 */
98 public void resetValue(Object object) throws IllegalStateException, IllegalArgumentException;
99
100 /**
101 * @deprecated No longer supported
102 */
103 public void checkValidity(Object object) throws ValidityException, IllegalStateException;
104
105 /**
106 * Creates a new instance of the object described by this field.
107 *
108 * @param parent
109 * The object for which the field is created
110 * @return A new instance of the field's value
111 * @throws IllegalStateException
112 * This field is a simple type and cannot be instantiated
113 */
114 public T newInstance(Object parent) throws IllegalStateException;
115
116 }