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 2004 (C) Intalio, Inc. All Rights Reserved.
42 *
43 * $Id$
44 */
45 package org.exolab.castor.xml.handlers;
46
47 import java.lang.reflect.Method;
48 import java.lang.reflect.Modifier;
49
50 import org.exolab.castor.mapping.FieldDescriptor;
51 import org.exolab.castor.mapping.FieldHandler;
52 import org.exolab.castor.mapping.GeneralizedFieldHandler;
53 import org.exolab.castor.mapping.MappingException;
54
55 /**
56 * An implementation of GeneralizedFieldHandler for classes that have a built-in
57 * valueOf(String) factory method, such as type-safe enumeration classes,
58 * java.sql.Timestamp, etc.
59 *
60 * @author <a href="kvisco@intalio.com">Keith Visco</a>
61 * @version $Revision$ $Date: 2006-04-14 04:14:43 -0600 (Fri, 14 Apr 2006) $
62 * @see FieldDescriptor
63 * @see FieldHandler
64 */
65 public class ValueOfFieldHandler extends GeneralizedFieldHandler {
66
67 /** The Class[] holding the argument types of the factory method. */
68 private static final Class[] ARGS = new Class[] {String.class};
69 /** The Factory Method name. */
70 private static final String METHOD_NAME = "valueOf";
71
72 /** The class type for this FieldHandler. */
73 private final Class _type;
74 /** The <code>valueOf</code> method reference. */
75 private final Method _valueOf;
76
77 /**
78 * Creates a new ValueOfFieldHandler.
79 *
80 * @param type the class type to create the FieldHandler for
81 * @throws MappingException if the valueOf method cannot be found
82 */
83 public ValueOfFieldHandler(final Class type) throws MappingException {
84 super();
85 if (type == null) {
86 throw new IllegalArgumentException("The argument 'type' must not be null.");
87 }
88
89 _type = type;
90
91 Method method = null;
92 try {
93 method = type.getMethod(METHOD_NAME, ARGS);
94 } catch (java.lang.NoSuchMethodException nsme) {
95 throw new MappingException(nsme);
96 }
97 if (!Modifier.isStatic(method.getModifiers())) {
98 String err = "No static method '" + METHOD_NAME + "' found in class: " + type.getName();
99 throw new MappingException(err);
100 }
101
102 _valueOf = method;
103 } //-- ValueOfFieldHandler
104
105 /**
106 * This method is used to convert the value when the getValue method is
107 * called. The getValue method will obtain the actual field value from given
108 * 'parent' object. This convert method is then invoked with the field's
109 * value. The value returned from this method will be the actual value
110 * returned by getValue method.
111 *
112 * @param value the object value to convert after performing a get operation
113 * @return the converted value.
114 */
115 public Object convertUponGet(final Object value) {
116 //-- no conversion necessary for marshaling
117 return value;
118 } //-- convertUponGet
119
120 /**
121 * This method is used to convert the value when the setValue method is
122 * called. The setValue method will call this method to obtain the converted
123 * value. The converted value will then be used as the value to set for the
124 * field.
125 *
126 * @param value the object value to convert before performing a set
127 * operation
128 * @return the converted value.
129 */
130 public Object convertUponSet(final Object value) {
131 Object[] args = new Object[1];
132
133 if (value != null) {
134 args[0] = value.toString();
135 }
136
137 Object result = null;
138
139 try {
140 result = _valueOf.invoke(null, args);
141 } catch (java.lang.IllegalAccessException iae) {
142 throw new IllegalStateException(iae.getMessage());
143 } catch (java.lang.reflect.InvocationTargetException ite) {
144 throw new IllegalStateException(ite.getMessage());
145 }
146
147 return result;
148 } //-- convertUponSet;
149
150 /**
151 * Returns the class type for the field that this GeneralizedFieldHandler
152 * converts to and from. This should be the type that is used in the object
153 * model.
154 *
155 * @return the class type of of the field
156 */
157 public Class getFieldType() {
158 return _type;
159 } //-- getFieldType
160
161 /**
162 * Creates a new instance of the object described by this field.
163 *
164 * @param parent The object for which the field is created
165 * @return A new instance of the field's value
166 * @throws IllegalStateException This field is a simple type and cannot be
167 * instantiated
168 */
169 public Object newInstance(final Object parent) throws IllegalStateException {
170 return null;
171 }
172
173 } // -- ValueOfFieldHandler