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18 package org.apache.commons.beanutils;
19
20 import org.apache.commons.collections.Closure;
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23
24 import java.lang.reflect.InvocationTargetException;
25
26
27 /***
28 * <p><code>Closure</code> that sets a property.</p>
29 * <p>
30 * An implementation of <code>org.apache.commons.collections.Closure</code> that updates
31 * a specified property on the object provided with a specified value.
32 * The <code>BeanPropertyValueChangeClosure</code> constructor takes two parameters which determine
33 * what property will be updated and with what value.
34 * <dl>
35 * <dt>
36 * <b><code>
37 * <pre>public BeanPropertyValueChangeClosure( String propertyName, Object propertyValue )</pre>
38 * </code></b>
39 * </dt>
40 * <dd>
41 * Will create a <code>Closure</code> that will update an object by setting the property
42 * specified by <code>propertyName</code> to the value specified by <code>propertyValue</code>.
43 * </dd>
44 * </dl>
45 *
46 * <p/>
47 * <strong>Note:</strong> Property names can be a simple, nested, indexed, or mapped property as defined by
48 * <code>org.apache.commons.beanutils.PropertyUtils</code>. If any object in the property path
49 * specified by <code>propertyName</code> is <code>null</code> then the outcome is based on the
50 * value of the <code>ignoreNull</code> attribute.
51 *
52 * <p/>
53 * A typical usage might look like:
54 * <code><pre>
55 * // create the closure
56 * BeanPropertyValueChangeClosure closure =
57 * new BeanPropertyValueChangeClosure( "activeEmployee", Boolean.TRUE );
58 *
59 * // update the Collection
60 * CollectionUtils.forAllDo( peopleCollection, closure );
61 * </pre></code>
62 * <p/>
63 *
64 * This would take a <code>Collection</code> of person objects and update the
65 * <code>activeEmployee</code> property of each object in the <code>Collection</code> to
66 * <code>true</code>. Assuming...
67 * <ul>
68 * <li>
69 * The top level object in the <code>peopleCollection</code> is an object which represents a
70 * person.
71 * </li>
72 * <li>
73 * The person object has a <code>setActiveEmployee( boolean )</code> method which updates
74 * the value for the object's <code>activeEmployee</code> property.
75 * </li>
76 * </ul>
77 *
78 * @author Norm Deane
79 * @see org.apache.commons.beanutils.PropertyUtils
80 * @see org.apache.commons.collections.Closure
81 */
82 public class BeanPropertyValueChangeClosure implements Closure {
83
84 /*** For logging. */
85 private final Log log = LogFactory.getLog(this.getClass());
86
87 /***
88 * The name of the property which will be updated when this <code>Closure</code> executes.
89 */
90 private String propertyName;
91
92 /***
93 * The value that the property specified by <code>propertyName</code>
94 * will be updated to when this <code>Closure</code> executes.
95 */
96 private Object propertyValue;
97
98 /***
99 * Determines whether <code>null</code> objects in the property path will genenerate an
100 * <code>IllegalArgumentException</code> or not. If set to <code>true</code> then if any objects
101 * in the property path leading up to the target property evaluate to <code>null</code> then the
102 * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged but
103 * not rethrown. If set to <code>false</code> then if any objects in the property path leading
104 * up to the target property evaluate to <code>null</code> then the
105 * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged and
106 * rethrown.
107 */
108 private boolean ignoreNull;
109
110 /***
111 * Constructor which takes the name of the property to be changed, the new value to set
112 * the property to, and assumes <code>ignoreNull</code> to be <code>false</code>.
113 *
114 * @param propertyName The name of the property that will be updated with the value specified by
115 * <code>propertyValue</code>.
116 * @param propertyValue The value that <code>propertyName</code> will be set to on the target
117 * object.
118 * @throws IllegalArgumentException If the propertyName provided is null or empty.
119 */
120 public BeanPropertyValueChangeClosure(String propertyName, Object propertyValue) {
121 this(propertyName, propertyValue, false);
122 }
123
124 /***
125 * Constructor which takes the name of the property to be changed, the new value to set
126 * the property to and a boolean which determines whether <code>null</code> objects in the
127 * property path will genenerate an <code>IllegalArgumentException</code> or not.
128 *
129 * @param propertyName The name of the property that will be updated with the value specified by
130 * <code>propertyValue</code>.
131 * @param propertyValue The value that <code>propertyName</code> will be set to on the target
132 * object.
133 * @param ignoreNull Determines whether <code>null</code> objects in the property path will
134 * genenerate an <code>IllegalArgumentException</code> or not.
135 * @throws IllegalArgumentException If the propertyName provided is null or empty.
136 */
137 public BeanPropertyValueChangeClosure(String propertyName, Object propertyValue, boolean ignoreNull) {
138 super();
139
140 if ((propertyName != null) && (propertyName.length() > 0)) {
141 this.propertyName = propertyName;
142 this.propertyValue = propertyValue;
143 this.ignoreNull = ignoreNull;
144 } else {
145 throw new IllegalArgumentException("propertyName cannot be null or empty");
146 }
147 }
148
149 /***
150 * Updates the target object provided using the property update criteria provided when this
151 * <code>BeanPropertyValueChangeClosure</code> was constructed. If any object in the property
152 * path leading up to the target property is <code>null</code> then the outcome will be based on
153 * the value of the <code>ignoreNull</code> attribute. By default, <code>ignoreNull</code> is
154 * <code>false</code> and would result in an <code>IllegalArgumentException</code> if an object
155 * in the property path leading up to the target property is <code>null</code>.
156 *
157 * @param object The object to be updated.
158 * @throws IllegalArgumentException If an IllegalAccessException, InvocationTargetException, or
159 * NoSuchMethodException is thrown when trying to access the property specified on the object
160 * provided. Or if an object in the property path provided is <code>null</code> and
161 * <code>ignoreNull</code> is set to <code>false</code>.
162 */
163 public void execute(Object object) {
164
165 try {
166 PropertyUtils.setProperty(object, propertyName, propertyValue);
167 } catch (IllegalArgumentException e) {
168 final String errorMsg = "Unable to execute Closure. Null value encountered in property path...";
169
170 if (ignoreNull) {
171 log.warn("WARNING: " + errorMsg, e);
172 } else {
173 log.error("ERROR: " + errorMsg, e);
174 throw e;
175 }
176 } catch (IllegalAccessException e) {
177 final String errorMsg = "Unable to access the property provided.";
178 log.error(errorMsg, e);
179 throw new IllegalArgumentException(errorMsg);
180 } catch (InvocationTargetException e) {
181 final String errorMsg = "Exception occurred in property's getter";
182 log.error(errorMsg, e);
183 throw new IllegalArgumentException(errorMsg);
184 } catch (NoSuchMethodException e) {
185 final String errorMsg = "Property not found";
186 log.error(errorMsg, e);
187 throw new IllegalArgumentException(errorMsg);
188 }
189 }
190
191 /***
192 * Returns the name of the property which will be updated when this <code>Closure</code> executes.
193 *
194 * @return The name of the property which will be updated when this <code>Closure</code> executes.
195 */
196 public String getPropertyName() {
197 return propertyName;
198 }
199
200 /***
201 * Returns the value that the property specified by <code>propertyName</code>
202 * will be updated to when this <code>Closure</code> executes.
203 *
204 * @return The value that the property specified by <code>propertyName</code>
205 * will be updated to when this <code>Closure</code> executes.
206 */
207 public Object getPropertyValue() {
208 return propertyValue;
209 }
210
211 /***
212 * Returns the flag that determines whether <code>null</code> objects in the property path will
213 * genenerate an <code>IllegalArgumentException</code> or not. If set to <code>true</code> then
214 * if any objects in the property path leading up to the target property evaluate to
215 * <code>null</code> then the <code>IllegalArgumentException</code> throw by
216 * <code>PropertyUtils</code> will be logged but not rethrown. If set to <code>false</code> then
217 * if any objects in the property path leading up to the target property evaluate to
218 * <code>null</code> then the <code>IllegalArgumentException</code> throw by
219 * <code>PropertyUtils</code> will be logged and rethrown.
220 *
221 * @return The flag that determines whether <code>null</code> objects in the property path will
222 * genenerate an <code>IllegalArgumentException</code> or not.
223 */
224 public boolean isIgnoreNull() {
225 return ignoreNull;
226 }
227 }