001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.beanutils;
019
020import org.apache.commons.collections.Closure;
021import org.apache.commons.logging.Log;
022import org.apache.commons.logging.LogFactory;
023
024import java.lang.reflect.InvocationTargetException;
025
026
027/**
028 * <p><code>Closure</code> that sets a property.</p>
029 * <p>
030 * An implementation of <code>org.apache.commons.collections.Closure</code> that updates
031 * a specified property on the object provided with a specified value.
032 * The <code>BeanPropertyValueChangeClosure</code> constructor takes two parameters which determine
033 * what property will be updated and with what value.
034 * <dl>
035 *    <dt>
036 *       <code>public BeanPropertyValueChangeClosure( String propertyName, Object propertyValue )</code>
037 *    </dt>
038 *    <dd>
039 *       Will create a <code>Closure</code> that will update an object by setting the property
040 *       specified by <code>propertyName</code> to the value specified by <code>propertyValue</code>.
041 *    </dd>
042 * </dl>
043 *
044 * <p>
045 * <strong>Note:</strong> Property names can be a simple, nested, indexed, or mapped property as defined by
046 * <code>org.apache.commons.beanutils.PropertyUtils</code>.  If any object in the property path
047 * specified by <code>propertyName</code> is <code>null</code> then the outcome is based on the
048 * value of the <code>ignoreNull</code> attribute.
049 * </p>
050 * <p>
051 * A typical usage might look like:
052 * </p>
053 * <pre><code>
054 * // create the closure
055 * BeanPropertyValueChangeClosure closure =
056 *    new BeanPropertyValueChangeClosure( "activeEmployee", Boolean.TRUE );
057 *
058 * // update the Collection
059 * CollectionUtils.forAllDo( peopleCollection, closure );
060 * </code></pre>
061 *
062 * This would take a <code>Collection</code> of person objects and update the
063 * <code>activeEmployee</code> property of each object in the <code>Collection</code> to
064 * <code>true</code>. Assuming...
065 * <ul>
066 *    <li>
067 *       The top level object in the <code>peopleCollection</code> is an object which represents a
068 *       person.
069 *    </li>
070 *    <li>
071 *       The person object has a <code>setActiveEmployee( boolean )</code> method which updates
072 *       the value for the object's <code>activeEmployee</code> property.
073 *    </li>
074 * </ul>
075 *
076 * @version $Id$
077 * @see org.apache.commons.beanutils.PropertyUtils
078 * @see org.apache.commons.collections.Closure
079 */
080public class BeanPropertyValueChangeClosure implements Closure {
081
082    /** For logging. */
083    private final Log log = LogFactory.getLog(this.getClass());
084
085    /**
086     * The name of the property which will be updated when this <code>Closure</code> executes.
087     */
088    private String propertyName;
089
090    /**
091     * The value that the property specified by <code>propertyName</code>
092     * will be updated to when this <code>Closure</code> executes.
093     */
094    private Object propertyValue;
095
096    /**
097     * Determines whether <code>null</code> objects in the property path will genenerate an
098     * <code>IllegalArgumentException</code> or not. If set to <code>true</code> then if any objects
099     * in the property path leading up to the target property evaluate to <code>null</code> then the
100     * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged but
101     * not rethrown.  If set to <code>false</code> then if any objects in the property path leading
102     * up to the target property evaluate to <code>null</code> then the
103     * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged and
104     * rethrown.
105     */
106    private boolean ignoreNull;
107
108    /**
109     * Constructor which takes the name of the property to be changed, the new value to set
110     * the property to, and assumes <code>ignoreNull</code> to be <code>false</code>.
111     *
112     * @param propertyName The name of the property that will be updated with the value specified by
113     * <code>propertyValue</code>.
114     * @param propertyValue The value that <code>propertyName</code> will be set to on the target
115     * object.
116     * @throws IllegalArgumentException If the propertyName provided is null or empty.
117     */
118    public BeanPropertyValueChangeClosure(final String propertyName, final Object propertyValue) {
119        this(propertyName, propertyValue, false);
120    }
121
122    /**
123     * Constructor which takes the name of the property to be changed, the new value to set
124     * the property to and a boolean which determines whether <code>null</code> objects in the
125     * property path will genenerate an <code>IllegalArgumentException</code> or not.
126     *
127     * @param propertyName The name of the property that will be updated with the value specified by
128     * <code>propertyValue</code>.
129     * @param propertyValue The value that <code>propertyName</code> will be set to on the target
130     * object.
131     * @param ignoreNull Determines whether <code>null</code> objects in the property path will
132     * genenerate an <code>IllegalArgumentException</code> or not.
133     * @throws IllegalArgumentException If the propertyName provided is null or empty.
134     */
135    public BeanPropertyValueChangeClosure(final String propertyName, final Object propertyValue, final boolean ignoreNull) {
136        super();
137
138        if ((propertyName != null) && (propertyName.length() > 0)) {
139            this.propertyName = propertyName;
140            this.propertyValue = propertyValue;
141            this.ignoreNull = ignoreNull;
142        } else {
143            throw new IllegalArgumentException("propertyName cannot be null or empty");
144        }
145    }
146
147    /**
148     * Updates the target object provided using the property update criteria provided when this
149     * <code>BeanPropertyValueChangeClosure</code> was constructed.  If any object in the property
150     * path leading up to the target property is <code>null</code> then the outcome will be based on
151     * the value of the <code>ignoreNull</code> attribute. By default, <code>ignoreNull</code> is
152     * <code>false</code> and would result in an <code>IllegalArgumentException</code> if an object
153     * in the property path leading up to the target property is <code>null</code>.
154     *
155     * @param object The object to be updated.
156     * @throws IllegalArgumentException If an IllegalAccessException, InvocationTargetException, or
157     * NoSuchMethodException is thrown when trying to access the property specified on the object
158     * provided. Or if an object in the property path provided is <code>null</code> and
159     * <code>ignoreNull</code> is set to <code>false</code>.
160     */
161    public void execute(final Object object) {
162
163        try {
164            PropertyUtils.setProperty(object, propertyName, propertyValue);
165        } catch (final IllegalArgumentException e) {
166            final String errorMsg = "Unable to execute Closure. Null value encountered in property path...";
167
168            if (ignoreNull) {
169                log.warn("WARNING: " + errorMsg + e);
170            } else {
171                final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
172                if (!BeanUtils.initCause(iae, e)) {
173                    log.error(errorMsg, e);
174                }
175                throw iae;
176            }
177        } catch (final IllegalAccessException e) {
178            final String errorMsg = "Unable to access the property provided.";
179            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
180            if (!BeanUtils.initCause(iae, e)) {
181                log.error(errorMsg, e);
182            }
183            throw iae;
184        } catch (final InvocationTargetException e) {
185            final String errorMsg = "Exception occurred in property's getter";
186            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
187            if (!BeanUtils.initCause(iae, e)) {
188                log.error(errorMsg, e);
189            }
190            throw iae;
191        } catch (final NoSuchMethodException e) {
192            final String errorMsg = "Property not found";
193            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
194            if (!BeanUtils.initCause(iae, e)) {
195                log.error(errorMsg, e);
196            }
197            throw iae;
198        }
199    }
200
201    /**
202     * Returns the name of the property which will be updated when this <code>Closure</code> executes.
203     *
204     * @return The name of the property which will be updated when this <code>Closure</code> executes.
205     */
206    public String getPropertyName() {
207        return propertyName;
208    }
209
210    /**
211     * Returns the value that the property specified by <code>propertyName</code>
212     * will be updated to when this <code>Closure</code> executes.
213     *
214     * @return The value that the property specified by <code>propertyName</code>
215     * will be updated to when this <code>Closure</code> executes.
216     */
217    public Object getPropertyValue() {
218        return propertyValue;
219    }
220
221    /**
222     * Returns the flag that determines whether <code>null</code> objects in the property path will
223     * genenerate an <code>IllegalArgumentException</code> or not. If set to <code>true</code> then
224     * if any objects in the property path leading up to the target property evaluate to
225     * <code>null</code> then the <code>IllegalArgumentException</code> throw by
226     * <code>PropertyUtils</code> will be logged but not rethrown.  If set to <code>false</code> then
227     * if any objects in the property path leading up to the target property evaluate to
228     * <code>null</code> then the <code>IllegalArgumentException</code> throw by
229     * <code>PropertyUtils</code> will be logged and rethrown.
230     *
231     * @return The flag that determines whether <code>null</code> objects in the property path will
232     * genenerate an <code>IllegalArgumentException</code> or not.
233     */
234    public boolean isIgnoreNull() {
235        return ignoreNull;
236    }
237}