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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package org.apache.commons.beanutils;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;


/**
 * 

Implementation of DynaBean that wraps a standard JavaBean * instance, so that DynaBean APIs can be used to access its properties.

* *

* The most common use cases for this class involve wrapping an existing java bean. * (This makes it different from the typical use cases for other DynaBean's.) * For example: *

*
 *  Object aJavaBean = ...;
 *  ...
 *  DynaBean db = new WrapDynaBean(aJavaBean);
 *  ...
 * 
* *

IMPLEMENTATION NOTE - This implementation does not * support the contains() and remove() methods.

* * @version $Id$ */ public class WrapDynaBean implements DynaBean, Serializable { // ---------------------------------------------------------- Constructors /** * Construct a new DynaBean associated with the specified * JavaBean instance. * * @param instance JavaBean instance to be wrapped */ public WrapDynaBean(final Object instance) { this(instance, null); } /** * Creates a new instance of {@code WrapDynaBean}, associates it with the specified * JavaBean instance, and initializes the bean's {@code DynaClass}. Using this * constructor this {@code WrapDynaBean} instance can be assigned a class which has * been configured externally. If no {@code WrapDynaClass} is provided, a new one is * created using a standard mechanism. * * @param instance JavaBean instance to be wrapped * @param cls the optional {@code WrapDynaClass} to be used for this bean * @since 1.9 */ public WrapDynaBean(final Object instance, final WrapDynaClass cls) { this.instance = instance; this.dynaClass = (cls != null) ? cls : (WrapDynaClass) getDynaClass(); } // ---------------------------------------------------- Instance Variables /** * The DynaClass "base class" that this DynaBean * is associated with. */ protected transient WrapDynaClass dynaClass = null; /** * The JavaBean instance wrapped by this WrapDynaBean. */ protected Object instance = null; // ------------------------------------------------------ DynaBean Methods /** * Does the specified mapped property contain a value for the specified * key value? * * @param name Name of the property to check * @param key Name of the key to check * @return true if the mapped property contains a value for * the specified key, otherwise false * * @throws IllegalArgumentException if there is no property * of the specified name */ public boolean contains(final String name, final String key) { throw new UnsupportedOperationException ("WrapDynaBean does not support contains()"); } /** * Return the value of a simple property with the specified name. * * @param name Name of the property whose value is to be retrieved * @return The property's value * * @throws IllegalArgumentException if there is no property * of the specified name */ public Object get(final String name) { Object value = null; try { value = getPropertyUtils().getSimpleProperty(instance, name); } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error reading property '" + name + "' nested exception - " + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error reading property '" + name + "', exception - " + t); } return (value); } /** * Return the value of an indexed property with the specified name. * * @param name Name of the property whose value is to be retrieved * @param index Index of the value to be retrieved * @return The indexed property's value * * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not indexed * @throws IndexOutOfBoundsException if the specified index * is outside the range of the underlying property * @throws NullPointerException if no array or List has been * initialized for this property */ public Object get(final String name, final int index) { Object value = null; try { value = getPropertyUtils().getIndexedProperty(instance, name, index); } catch (final IndexOutOfBoundsException e) { throw e; } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error reading indexed property '" + name + "' nested exception - " + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error reading indexed property '" + name + "', exception - " + t); } return (value); } /** * Return the value of a mapped property with the specified name, * or null if there is no value for the specified key. * * @param name Name of the property whose value is to be retrieved * @param key Key of the value to be retrieved * @return The mapped property's value * * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not mapped */ public Object get(final String name, final String key) { Object value = null; try { value = getPropertyUtils().getMappedProperty(instance, name, key); } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error reading mapped property '" + name + "' nested exception - " + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error reading mapped property '" + name + "', exception - " + t); } return (value); } /** * Return the DynaClass instance that describes the set of * properties available for this DynaBean. * @return The associated DynaClass */ public DynaClass getDynaClass() { if (dynaClass == null) { dynaClass = WrapDynaClass.createDynaClass(instance.getClass()); } return (this.dynaClass); } /** * Remove any existing value for the specified key on the * specified mapped property. * * @param name Name of the property for which a value is to * be removed * @param key Key of the value to be removed * * @throws IllegalArgumentException if there is no property * of the specified name */ public void remove(final String name, final String key) { throw new UnsupportedOperationException ("WrapDynaBean does not support remove()"); } /** * Set the value of a simple property with the specified name. * * @param name Name of the property whose value is to be set * @param value Value to which this property is to be set * * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws IllegalArgumentException if there is no property * of the specified name * @throws NullPointerException if an attempt is made to set a * primitive property to null */ public void set(final String name, final Object value) { try { getPropertyUtils().setSimpleProperty(instance, name, value); } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error setting property '" + name + "' nested exception -" + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error setting property '" + name + "', exception - " + t); } } /** * Set the value of an indexed property with the specified name. * * @param name Name of the property whose value is to be set * @param index Index of the property to be set * @param value Value to which this property is to be set * * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not indexed * @throws IndexOutOfBoundsException if the specified index * is outside the range of the underlying property */ public void set(final String name, final int index, final Object value) { try { getPropertyUtils().setIndexedProperty(instance, name, index, value); } catch (final IndexOutOfBoundsException e) { throw e; } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error setting indexed property '" + name + "' nested exception - " + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error setting indexed property '" + name + "', exception - " + t); } } /** * Set the value of a mapped property with the specified name. * * @param name Name of the property whose value is to be set * @param key Key of the property to be set * @param value Value to which this property is to be set * * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not mapped */ public void set(final String name, final String key, final Object value) { try { getPropertyUtils().setMappedProperty(instance, name, key, value); } catch (final InvocationTargetException ite) { final Throwable cause = ite.getTargetException(); throw new IllegalArgumentException ("Error setting mapped property '" + name + "' nested exception - " + cause); } catch (final Throwable t) { throw new IllegalArgumentException ("Error setting mapped property '" + name + "', exception - " + t); } } /** * Gets the bean instance wrapped by this DynaBean. * For most common use cases, * this object should already be known * and this method safely be ignored. * But some creators of frameworks using DynaBean's may * find this useful. * * @return the java bean Object wrapped by this DynaBean */ public Object getInstance() { return instance; } // ------------------------------------------------------ Protected Methods /** * Return the property descriptor for the specified property name. * * @param name Name of the property for which to retrieve the descriptor * @return The descriptor for the specified property * * @throws IllegalArgumentException if this is not a valid property * name for our DynaClass */ protected DynaProperty getDynaProperty(final String name) { final DynaProperty descriptor = getDynaClass().getDynaProperty(name); if (descriptor == null) { throw new IllegalArgumentException ("Invalid property name '" + name + "'"); } return (descriptor); } /** * Returns the {@code PropertyUtilsBean} instance to be used for accessing properties. * If available, this object is obtained from the associated {@code WrapDynaClass}. * * @return the associated {@code PropertyUtilsBean} */ private PropertyUtilsBean getPropertyUtils() { PropertyUtilsBean propUtils = null; if (dynaClass != null) { propUtils = dynaClass.getPropertyUtilsBean(); } return (propUtils != null) ? propUtils : PropertyUtilsBean.getInstance(); } }