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 1999-2002 (C) Intalio, Inc. All Rights Reserved.
42 *
43 * $Id$
44 */
45
46 package org.exolab.castor.mapping;
47
48 import java.util.Properties;
49
50 /**
51 * An extended version of the FieldHandler interface which is used for adding
52 * additional functionality while preserving backward compatability.
53 *
54 * @author <a href="kvisco@intalio.com">Keith Visco</a>
55 * @version $Revision$ $Date: 2005-08-03 15:11:51 -0600 (Wed, 03 Aug
56 * 2005) $
57 * @see FieldDescriptor
58 * @see FieldHandler
59 */
60 public abstract class AbstractFieldHandler<T> extends ExtendedFieldHandler<T> implements ConfigurableFieldHandler<T> {
61
62 /**
63 * The FieldDescriptor for the field that this handler is responsible for.
64 */
65 private FieldDescriptor _descriptor = null;
66
67 /**
68 * Configuration that can be used by subclasses when needed.
69 */
70 protected Properties _properties;
71
72 /**
73 * {@inheritDoc}
74 */
75 protected final FieldDescriptor getFieldDescriptor() {
76 return _descriptor;
77 }
78
79 /**
80 * {@inheritDoc}
81 */
82 public void setFieldDescriptor(FieldDescriptor fieldDesc) {
83 _descriptor = fieldDesc;
84 }
85
86 /**
87 * Returns true if the "handled" field has a value within the given object.
88 * <p>
89 * By default this just checks for null. Normally this method is needed for
90 * checking if a value has been set via a call to the setValue method, or if
91 * the primitive value has been initialised by the JVM.
92 * </p>
93 * <p>
94 * This method should be overloaded for improved value checking.
95 * </p>
96 *
97 * @return true if the given object has a value for the handled field
98 */
99 public boolean hasValue(final Object object) {
100 return (getValue(object) != null);
101 }
102
103 /**
104 * Empty implementation of the {@link ConfigurableFieldHandler} interface,
105 * for convenience purpose. Subclasses that want to use any configuration
106 * should override this method.
107 *
108 * @param config
109 * The configuration as specified in the mapping file.
110 */
111 public void setConfiguration(final Properties config) throws ValidityException {
112 }
113 }