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
018
019package org.apache.commons.beanutils;
020
021import java.io.Serializable;
022import java.lang.reflect.InvocationTargetException;
023
024
025/**
026 * <p>Implementation of <code>DynaBean</code> that wraps a standard JavaBean
027 * instance, so that DynaBean APIs can be used to access its properties.</p>
028 *
029 * <p>
030 * The most common use cases for this class involve wrapping an existing java bean.
031 * (This makes it different from the typical use cases for other <code>DynaBean</code>'s.)
032 * For example:
033 * </p>
034 * <code><pre>
035 *  Object aJavaBean = ...;
036 *  ...
037 *  DynaBean db = new WrapDynaBean(aJavaBean);
038 *  ...
039 * </pre></code>
040 *
041 * <p><strong>IMPLEMENTATION NOTE</strong> - This implementation does not
042 * support the <code>contains()</code> and <code>remove()</code> methods.</p>
043 *
044 * @version $Id$
045 */
046
047public class WrapDynaBean implements DynaBean, Serializable {
048
049
050    // ---------------------------------------------------------- Constructors
051
052
053    /**
054     * Construct a new <code>DynaBean</code> associated with the specified
055     * JavaBean instance.
056     *
057     * @param instance JavaBean instance to be wrapped
058     */
059    public WrapDynaBean(final Object instance) {
060
061        this(instance, null);
062
063    }
064
065    /**
066     * Creates a new instance of {@code WrapDynaBean}, associates it with the specified
067     * JavaBean instance, and initializes the bean's {@code DynaClass}. Using this
068     * constructor this {@code WrapDynaBean} instance can be assigned a class which has
069     * been configured externally. If no {@code WrapDynaClass} is provided, a new one is
070     * created using a standard mechanism.
071     *
072     * @param instance JavaBean instance to be wrapped
073     * @param cls the optional {@code WrapDynaClass} to be used for this bean
074     * @since 1.9
075     */
076    public WrapDynaBean(final Object instance, final WrapDynaClass cls) {
077
078        this.instance = instance;
079        this.dynaClass = (cls != null) ? cls : (WrapDynaClass) getDynaClass();
080
081    }
082
083    // ---------------------------------------------------- Instance Variables
084
085
086    /**
087     * The <code>DynaClass</code> "base class" that this DynaBean
088     * is associated with.
089     */
090    protected transient WrapDynaClass dynaClass = null;
091
092
093    /**
094     * The JavaBean instance wrapped by this WrapDynaBean.
095     */
096    protected Object instance = null;
097
098
099    // ------------------------------------------------------ DynaBean Methods
100
101
102    /**
103     * Does the specified mapped property contain a value for the specified
104     * key value?
105     *
106     * @param name Name of the property to check
107     * @param key Name of the key to check
108     * @return <code>true<code> if the mapped property contains a value for
109     * the specified key, otherwise <code>false</code>
110     *
111     * @throws IllegalArgumentException if there is no property
112     *  of the specified name
113     */
114    public boolean contains(final String name, final String key) {
115
116        throw new UnsupportedOperationException
117                ("WrapDynaBean does not support contains()");
118
119    }
120
121
122    /**
123     * Return the value of a simple property with the specified name.
124     *
125     * @param name Name of the property whose value is to be retrieved
126     * @return The property's value
127     *
128     * @throws IllegalArgumentException if there is no property
129     *  of the specified name
130     */
131    public Object get(final String name) {
132
133        Object value = null;
134        try {
135            value = getPropertyUtils().getSimpleProperty(instance, name);
136        } catch (final InvocationTargetException ite) {
137            final Throwable cause = ite.getTargetException();
138            throw new IllegalArgumentException
139                    ("Error reading property '" + name +
140                              "' nested exception - " + cause);
141        } catch (final Throwable t) {
142            throw new IllegalArgumentException
143                    ("Error reading property '" + name +
144                              "', exception - " + t);
145        }
146        return (value);
147
148    }
149
150
151    /**
152     * Return the value of an indexed property with the specified name.
153     *
154     * @param name Name of the property whose value is to be retrieved
155     * @param index Index of the value to be retrieved
156     * @return The indexed property's value
157     *
158     * @throws IllegalArgumentException if there is no property
159     *  of the specified name
160     * @throws IllegalArgumentException if the specified property
161     *  exists, but is not indexed
162     * @throws IndexOutOfBoundsException if the specified index
163     *  is outside the range of the underlying property
164     * @throws NullPointerException if no array or List has been
165     *  initialized for this property
166     */
167    public Object get(final String name, final int index) {
168
169        Object value = null;
170        try {
171            value = getPropertyUtils().getIndexedProperty(instance, name, index);
172        } catch (final IndexOutOfBoundsException e) {
173            throw e;
174        } catch (final InvocationTargetException ite) {
175            final Throwable cause = ite.getTargetException();
176            throw new IllegalArgumentException
177                    ("Error reading indexed property '" + name +
178                              "' nested exception - " + cause);
179        } catch (final Throwable t) {
180            throw new IllegalArgumentException
181                    ("Error reading indexed property '" + name +
182                              "', exception - " + t);
183        }
184        return (value);
185
186    }
187
188
189    /**
190     * Return the value of a mapped property with the specified name,
191     * or <code>null</code> if there is no value for the specified key.
192     *
193     * @param name Name of the property whose value is to be retrieved
194     * @param key Key of the value to be retrieved
195     * @return The mapped property's value
196     *
197     * @throws IllegalArgumentException if there is no property
198     *  of the specified name
199     * @throws IllegalArgumentException if the specified property
200     *  exists, but is not mapped
201     */
202    public Object get(final String name, final String key) {
203
204        Object value = null;
205        try {
206            value = getPropertyUtils().getMappedProperty(instance, name, key);
207        } catch (final InvocationTargetException ite) {
208            final Throwable cause = ite.getTargetException();
209            throw new IllegalArgumentException
210                    ("Error reading mapped property '" + name +
211                              "' nested exception - " + cause);
212        } catch (final Throwable t) {
213            throw new IllegalArgumentException
214                    ("Error reading mapped property '" + name +
215                              "', exception - " + t);
216        }
217        return (value);
218
219    }
220
221
222    /**
223     * Return the <code>DynaClass</code> instance that describes the set of
224     * properties available for this DynaBean.
225     * @return The associated DynaClass
226     */
227    public DynaClass getDynaClass() {
228
229        if (dynaClass == null) {
230            dynaClass = WrapDynaClass.createDynaClass(instance.getClass());
231        }
232
233        return (this.dynaClass);
234
235    }
236
237
238    /**
239     * Remove any existing value for the specified key on the
240     * specified mapped property.
241     *
242     * @param name Name of the property for which a value is to
243     *  be removed
244     * @param key Key of the value to be removed
245     *
246     * @throws IllegalArgumentException if there is no property
247     *  of the specified name
248     */
249    public void remove(final String name, final String key) {
250
251
252        throw new UnsupportedOperationException
253                ("WrapDynaBean does not support remove()");
254
255    }
256
257
258    /**
259     * Set the value of a simple property with the specified name.
260     *
261     * @param name Name of the property whose value is to be set
262     * @param value Value to which this property is to be set
263     *
264     * @throws ConversionException if the specified value cannot be
265     *  converted to the type required for this property
266     * @throws IllegalArgumentException if there is no property
267     *  of the specified name
268     * @throws NullPointerException if an attempt is made to set a
269     *  primitive property to null
270     */
271    public void set(final String name, final Object value) {
272
273        try {
274            getPropertyUtils().setSimpleProperty(instance, name, value);
275        } catch (final InvocationTargetException ite) {
276            final Throwable cause = ite.getTargetException();
277            throw new IllegalArgumentException
278                    ("Error setting property '" + name +
279                              "' nested exception -" + cause);
280        } catch (final Throwable t) {
281            throw new IllegalArgumentException
282                    ("Error setting property '" + name +
283                              "', exception - " + t);
284        }
285
286    }
287
288
289    /**
290     * Set the value of an indexed property with the specified name.
291     *
292     * @param name Name of the property whose value is to be set
293     * @param index Index of the property to be set
294     * @param value Value to which this property is to be set
295     *
296     * @throws ConversionException if the specified value cannot be
297     *  converted to the type required for this property
298     * @throws IllegalArgumentException if there is no property
299     *  of the specified name
300     * @throws IllegalArgumentException if the specified property
301     *  exists, but is not indexed
302     * @throws IndexOutOfBoundsException if the specified index
303     *  is outside the range of the underlying property
304     */
305    public void set(final String name, final int index, final Object value) {
306
307        try {
308            getPropertyUtils().setIndexedProperty(instance, name, index, value);
309        } catch (final IndexOutOfBoundsException e) {
310            throw e;
311        } catch (final InvocationTargetException ite) {
312            final Throwable cause = ite.getTargetException();
313            throw new IllegalArgumentException
314                    ("Error setting indexed property '" + name +
315                              "' nested exception - " + cause);
316        } catch (final Throwable t) {
317            throw new IllegalArgumentException
318                    ("Error setting indexed property '" + name +
319                              "', exception - " + t);
320        }
321
322    }
323
324
325    /**
326     * Set the value of a mapped property with the specified name.
327     *
328     * @param name Name of the property whose value is to be set
329     * @param key Key of the property to be set
330     * @param value Value to which this property is to be set
331     *
332     * @throws ConversionException if the specified value cannot be
333     *  converted to the type required for this property
334     * @throws IllegalArgumentException if there is no property
335     *  of the specified name
336     * @throws IllegalArgumentException if the specified property
337     *  exists, but is not mapped
338     */
339    public void set(final String name, final String key, final Object value) {
340
341        try {
342            getPropertyUtils().setMappedProperty(instance, name, key, value);
343        } catch (final InvocationTargetException ite) {
344            final Throwable cause = ite.getTargetException();
345            throw new IllegalArgumentException
346                    ("Error setting mapped property '" + name +
347                              "' nested exception - " + cause);
348        } catch (final Throwable t) {
349            throw new IllegalArgumentException
350                    ("Error setting mapped property '" + name +
351                              "', exception - " + t);
352        }
353
354    }
355
356    /**
357     * Gets the bean instance wrapped by this DynaBean.
358     * For most common use cases,
359     * this object should already be known
360     * and this method safely be ignored.
361     * But some creators of frameworks using <code>DynaBean</code>'s may
362     * find this useful.
363     *
364     * @return the java bean Object wrapped by this <code>DynaBean</code>
365     */
366    public Object getInstance() {
367        return instance;
368    }
369
370
371    // ------------------------------------------------------ Protected Methods
372
373
374    /**
375     * Return the property descriptor for the specified property name.
376     *
377     * @param name Name of the property for which to retrieve the descriptor
378     * @return The descriptor for the specified property
379     *
380     * @throws IllegalArgumentException if this is not a valid property
381     *  name for our DynaClass
382     */
383    protected DynaProperty getDynaProperty(final String name) {
384
385        final DynaProperty descriptor = getDynaClass().getDynaProperty(name);
386        if (descriptor == null) {
387            throw new IllegalArgumentException
388                    ("Invalid property name '" + name + "'");
389        }
390        return (descriptor);
391
392    }
393
394    /**
395     * Returns the {@code PropertyUtilsBean} instance to be used for accessing properties.
396     * If available, this object is obtained from the associated {@code WrapDynaClass}.
397     *
398     * @return the associated {@code PropertyUtilsBean}
399     */
400    private PropertyUtilsBean getPropertyUtils() {
401
402        PropertyUtilsBean propUtils = null;
403        if (dynaClass != null) {
404            propUtils = dynaClass.getPropertyUtilsBean();
405        }
406        return (propUtils != null) ? propUtils : PropertyUtilsBean.getInstance();
407
408    }
409}