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 *       <b><code>
037 *           <pre>public BeanPropertyValueChangeClosure( String propertyName, Object propertyValue )</pre>
038 *       </code></b>
039 *    </dt>
040 *    <dd>
041 *       Will create a <code>Closure</code> that will update an object by setting the property
042 *       specified by <code>propertyName</code> to the value specified by <code>propertyValue</code>.
043 *    </dd>
044 * </dl>
045 *
046 * <p/>
047 * <strong>Note:</strong> Property names can be a simple, nested, indexed, or mapped property as defined by
048 * <code>org.apache.commons.beanutils.PropertyUtils</code>.  If any object in the property path
049 * specified by <code>propertyName</code> is <code>null</code> then the outcome is based on the
050 * value of the <code>ignoreNull</code> attribute.
051 *
052 * <p/>
053 * A typical usage might look like:
054 * <code><pre>
055 * // create the closure
056 * BeanPropertyValueChangeClosure closure =
057 *    new BeanPropertyValueChangeClosure( "activeEmployee", Boolean.TRUE );
058 *
059 * // update the Collection
060 * CollectionUtils.forAllDo( peopleCollection, closure );
061 * </pre></code>
062 * <p/>
063 *
064 * This would take a <code>Collection</code> of person objects and update the
065 * <code>activeEmployee</code> property of each object in the <code>Collection</code> to
066 * <code>true</code>. Assuming...
067 * <ul>
068 *    <li>
069 *       The top level object in the <code>peopleCollection</code> is an object which represents a
070 *       person.
071 *    </li>
072 *    <li>
073 *       The person object has a <code>setActiveEmployee( boolean )</code> method which updates
074 *       the value for the object's <code>activeEmployee</code> property.
075 *    </li>
076 * </ul>
077 *
078 * @version $Id$
079 * @see org.apache.commons.beanutils.PropertyUtils
080 * @see org.apache.commons.collections.Closure
081 */
082public class BeanPropertyValueChangeClosure implements Closure {
083
084    /** For logging. */
085    private final Log log = LogFactory.getLog(this.getClass());
086
087    /**
088     * The name of the property which will be updated when this <code>Closure</code> executes.
089     */
090    private String propertyName;
091
092    /**
093     * The value that the property specified by <code>propertyName</code>
094     * will be updated to when this <code>Closure</code> executes.
095     */
096    private Object propertyValue;
097
098    /**
099     * 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(final String propertyName, final 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(final String propertyName, final Object propertyValue, final 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(final Object object) {
164
165        try {
166            PropertyUtils.setProperty(object, propertyName, propertyValue);
167        } catch (final 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                final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
174                if (!BeanUtils.initCause(iae, e)) {
175                    log.error(errorMsg, e);
176                }
177                throw iae;
178            }
179        } catch (final IllegalAccessException e) {
180            final String errorMsg = "Unable to access the property provided.";
181            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
182            if (!BeanUtils.initCause(iae, e)) {
183                log.error(errorMsg, e);
184            }
185            throw iae;
186        } catch (final InvocationTargetException e) {
187            final String errorMsg = "Exception occurred in property's getter";
188            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
189            if (!BeanUtils.initCause(iae, e)) {
190                log.error(errorMsg, e);
191            }
192            throw iae;
193        } catch (final NoSuchMethodException e) {
194            final String errorMsg = "Property not found";
195            final IllegalArgumentException iae = new IllegalArgumentException(errorMsg);
196            if (!BeanUtils.initCause(iae, e)) {
197                log.error(errorMsg, e);
198            }
199            throw iae;
200        }
201    }
202
203    /**
204     * Returns the name of the property which will be updated when this <code>Closure</code> executes.
205     *
206     * @return The name of the property which will be updated when this <code>Closure</code> executes.
207     */
208    public String getPropertyName() {
209        return propertyName;
210    }
211
212    /**
213     * Returns the value that the property specified by <code>propertyName</code>
214     * will be updated to when this <code>Closure</code> executes.
215     *
216     * @return The value that the property specified by <code>propertyName</code>
217     * will be updated to when this <code>Closure</code> executes.
218     */
219    public Object getPropertyValue() {
220        return propertyValue;
221    }
222
223    /**
224     * Returns the flag that determines whether <code>null</code> objects in the property path will
225     * genenerate an <code>IllegalArgumentException</code> or not. If set to <code>true</code> then
226     * if any objects in the property path leading up to the target property evaluate to
227     * <code>null</code> then the <code>IllegalArgumentException</code> throw by
228     * <code>PropertyUtils</code> will be logged but not rethrown.  If set to <code>false</code> then
229     * if any objects in the property path leading up to the target property evaluate to
230     * <code>null</code> then the <code>IllegalArgumentException</code> throw by
231     * <code>PropertyUtils</code> will be logged and rethrown.
232     *
233     * @return The flag that determines whether <code>null</code> objects in the property path will
234     * genenerate an <code>IllegalArgumentException</code> or not.
235     */
236    public boolean isIgnoreNull() {
237        return ignoreNull;
238    }
239}