| /* |
| * 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.beanutils2; |
| |
| import java.lang.reflect.InvocationTargetException; |
| |
| import org.apache.commons.collections4.Transformer; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| |
| /** |
| * <p><code>Transformer</code> that outputs a property value.</p> |
| * |
| * <p>An implementation of <code>org.apache.commons.collections4.Transformer</code> that transforms |
| * the object provided by returning the value of a specified property of the object. The |
| * constructor for <code>BeanToPropertyValueTransformer</code> requires the name of the property |
| * that will be used in the transformation. The property can be a simple, nested, indexed, or |
| * mapped property as defined by <code>org.apache.commons.beanutils2.PropertyUtils</code>. If any |
| * object in the property path specified by <code>propertyName</code> is <code>null</code> then the |
| * outcome is based on the value of the <code>ignoreNull</code> attribute. |
| * </p> |
| * |
| * <p> |
| * A typical usage might look like: |
| * </p> |
| * <pre><code> |
| * // create the transformer |
| * BeanToPropertyValueTransformer transformer = new BeanToPropertyValueTransformer( "person.address.city" ); |
| * |
| * // transform the Collection |
| * Collection peoplesCities = CollectionUtils.collect( peopleCollection, transformer ); |
| * </code></pre> |
| * |
| * <p> |
| * This would take a <code>Collection</code> of person objects and return a <code>Collection</code> |
| * of objects which represents the cities in which each person lived. Assuming... |
| * <ul> |
| * <li> |
| * The top level object in the <code>peeopleCollection</code> is an object which represents a |
| * person. |
| * </li> |
| * <li> |
| * The person object has a <code>getAddress()</code> method which returns an object which |
| * represents a person's address. |
| * </li> |
| * <li> |
| * The address object has a <code>getCity()</code> method which returns an object which |
| * represents the city in which a person lives. |
| * </li> |
| * </ul> |
| * |
| * @see org.apache.commons.beanutils2.PropertyUtils |
| * @see org.apache.commons.collections4.Transformer |
| */ |
| public class BeanToPropertyValueTransformer implements Transformer { |
| |
| /** For logging. */ |
| private final Log log = LogFactory.getLog(this.getClass()); |
| |
| /** The name of the property that will be used in the transformation of the object. */ |
| private String propertyName; |
| |
| /** |
| * <p>Should null objects on the property path throw an <code>IllegalArgumentException</code>?</p> |
| * <p> |
| * Determines whether <code>null</code> objects in the property path will genenerate an |
| * <code>IllegalArgumentException</code> or not. If set to <code>true</code> then if any objects |
| * in the property path evaluate to <code>null</code> then the |
| * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged but |
| * not rethrown and <code>null</code> will be returned. If set to <code>false</code> then if any |
| * objects in the property path evaluate to <code>null</code> then the |
| * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged and |
| * rethrown. |
| * </p> |
| */ |
| private boolean ignoreNull; |
| |
| /** |
| * Constructs a Transformer which does not ignore nulls. |
| * Constructor which takes the name of the property that will be used in the transformation and |
| * assumes <code>ignoreNull</code> to be <code>false</code>. |
| * |
| * @param propertyName The name of the property that will be used in the transformation. |
| * @throws IllegalArgumentException If the <code>propertyName</code> is <code>null</code> or |
| * empty. |
| */ |
| public BeanToPropertyValueTransformer(final String propertyName) { |
| this(propertyName, false); |
| } |
| |
| /** |
| * Constructs a Transformer and sets ignoreNull. |
| * Constructor which takes the name of the property that will be used in the transformation and |
| * a boolean which determines whether <code>null</code> objects in the property path will |
| * genenerate an <code>IllegalArgumentException</code> or not. |
| * |
| * @param propertyName The name of the property that will be used in the transformation. |
| * @param ignoreNull Determines whether <code>null</code> objects in the property path will |
| * genenerate an <code>IllegalArgumentException</code> or not. |
| * @throws IllegalArgumentException If the <code>propertyName</code> is <code>null</code> or |
| * empty. |
| */ |
| public BeanToPropertyValueTransformer(final String propertyName, final boolean ignoreNull) { |
| super(); |
| |
| if (propertyName != null && propertyName.length() > 0) { |
| this.propertyName = propertyName; |
| this.ignoreNull = ignoreNull; |
| } else { |
| throw new IllegalArgumentException( |
| "propertyName cannot be null or empty"); |
| } |
| } |
| |
| /** |
| * Returns the value of the property named in the transformer's constructor for |
| * the object provided. If any object in the property path leading up to the target property is |
| * <code>null</code> then the outcome will be based on the value of the <code>ignoreNull</code> |
| * attribute. By default, <code>ignoreNull</code> is <code>false</code> and would result in an |
| * <code>IllegalArgumentException</code> if an object in the property path leading up to the |
| * target property is <code>null</code>. |
| * |
| * @param object The object to be transformed. |
| * @return The value of the property named in the transformer's constructor for the object |
| * provided. |
| * @throws IllegalArgumentException If an IllegalAccessException, InvocationTargetException, or |
| * NoSuchMethodException is thrown when trying to access the property specified on the object |
| * provided. Or if an object in the property path provided is <code>null</code> and |
| * <code>ignoreNull</code> is set to <code>false</code>. |
| */ |
| @Override |
| public Object transform(final Object object) { |
| |
| Object propertyValue = null; |
| |
| try { |
| propertyValue = PropertyUtils.getProperty(object, propertyName); |
| } catch (final IllegalArgumentException e) { |
| final String errorMsg = "Problem during transformation. Null value encountered in property path..."; |
| |
| if (ignoreNull) { |
| log.warn("WARNING: " + errorMsg + e); |
| } else { |
| final IllegalArgumentException iae = new IllegalArgumentException(errorMsg); |
| if (!BeanUtils.initCause(iae, e)) { |
| log.error(errorMsg, e); |
| } |
| throw iae; |
| } |
| } catch (final IllegalAccessException e) { |
| final String errorMsg = "Unable to access the property provided."; |
| final IllegalArgumentException iae = new IllegalArgumentException(errorMsg); |
| if (!BeanUtils.initCause(iae, e)) { |
| log.error(errorMsg, e); |
| } |
| throw iae; |
| } catch (final InvocationTargetException e) { |
| final String errorMsg = "Exception occurred in property's getter"; |
| final IllegalArgumentException iae = new IllegalArgumentException(errorMsg); |
| if (!BeanUtils.initCause(iae, e)) { |
| log.error(errorMsg, e); |
| } |
| throw iae; |
| } catch (final NoSuchMethodException e) { |
| final String errorMsg = "No property found for name [" + |
| propertyName + "]"; |
| final IllegalArgumentException iae = new IllegalArgumentException(errorMsg); |
| if (!BeanUtils.initCause(iae, e)) { |
| log.error(errorMsg, e); |
| } |
| throw iae; |
| } |
| |
| return propertyValue; |
| } |
| |
| /** |
| * Returns the name of the property that will be used in the transformation of the bean. |
| * |
| * @return The name of the property that will be used in the transformation of the bean. |
| */ |
| public String getPropertyName() { |
| return propertyName; |
| } |
| |
| /** |
| * Returns the flag which determines whether <code>null</code> objects in the property path will |
| * genenerate an <code>IllegalArgumentException</code> or not. If set to <code>true</code> then |
| * if any objects in the property path evaluate to <code>null</code> then the |
| * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged but |
| * not rethrown and <code>null</code> will be returned. If set to <code>false</code> then if any |
| * objects in the property path evaluate to <code>null</code> then the |
| * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged and |
| * rethrown. |
| * |
| * @return The flag which determines whether <code>null</code> objects in the property path will |
| * genenerate an <code>IllegalArgumentException</code> or not. |
| */ |
| public boolean isIgnoreNull() { |
| return ignoreNull; |
| } |
| } |