src/main/java/org/apache/commons/beanutils2/BeanPropertyValueChangeConsumer.java

/*
 * 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
 *
 *      https://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 java.util.function.Consumer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * <p>
 * {@code Closure} that sets a property.
 * </p>
 * <p>
 * An implementation of {@link java.util.function.Consumer} that updates a specified property on the object provided with a specified value. The
 * {@code BeanPropertyValueChangeClosure} constructor takes two parameters which determine what property will be updated and with what value.
 * <dl>
 * <dt>{@code public BeanPropertyValueChangeClosure( String propertyName, Object propertyValue )}</dt>
 * <dd>Will create a {@code Closure} that will update an object by setting the property specified by
 * {@code propertyName</code> to the value specified by <code>propertyValue}.
 *    </dd>
 * </dl>
 *
 * <p>
 * <strong>Note:</strong> Property names can be a simple, nested, indexed, or mapped property as defined by
 * {@code org.apache.commons.beanutils2.PropertyUtils}.  If any object in the property path
 * specified by {@code propertyName</code> is <code>null} then the outcome is based on the
 * value of the {@code ignoreNull} attribute.
 * </p>
 * <p>
 * A typical usage might look like:
 * </p>
 * <pre>{@code
 * // create the closure
 * BeanPropertyValueChangeClosure closure =
 *    new BeanPropertyValueChangeClosure( "activeEmployee", Boolean.TRUE );
 *
 * // update the Collection
 * CollectionUtils.forAllDo( peopleCollection, closure );
 * }</pre>
 *
 * This would take a {@code Collection} of person objects and update the
 * {@code activeEmployee</code> property of each object in the <code>Collection} to {@code true}. Assuming...
 * <ul>
 * <li>The top level object in the {@code peopleCollection} is an object which represents a person.</li>
 * <li>The person object has a {@code setActiveEmployee( boolean )} method which updates the value for the object's {@code activeEmployee} property.</li>
 * </ul>
 *
 * @param <T> The type of the input to the operation
 * @param <V> The property value type.
 * @see org.apache.commons.beanutils2.PropertyUtils
 * @see java.util.function.Consumer
 */
public class BeanPropertyValueChangeConsumer<T, V> implements Consumer<T> {

    /** For logging. Each subclass gets its own log instance. */
    private final Log log = LogFactory.getLog(this.getClass());

    /**
     * The name of the property which will be updated when this {@code Closure} executes.
     */
    private final String propertyName;

    /**
     * The value that the property specified by {@code propertyName} will be updated to when this {@code Closure} executes.
     */
    private final V propertyValue;

    /**
     * Determines whether {@code null} objects in the property path will generate an
     * {@code IllegalArgumentException</code> or not. If set to <code>true} then if any objects
     * in the property path leading up to the target property evaluate to {@code null} then the
     * {@code IllegalArgumentException</code> throw by <code>PropertyUtils} will be logged but
     * not re-thrown.  If set to {@code false} then if any objects in the property path leading
     * up to the target property evaluate to {@code null} then the
     * {@code IllegalArgumentException</code> throw by <code>PropertyUtils} will be logged and re-thrown.
     */
    private final boolean ignoreNull;

    /**
     * Constructor which takes the name of the property to be changed, the new value to set the property to, and assumes
     * {@code ignoreNull</code> to be <code>false}.
     *
     * @param propertyName  The name of the property that will be updated with the value specified by {@code propertyValue}.
     * @param propertyValue The value that {@code propertyName} will be set to on the target object.
     * @throws IllegalArgumentException If the propertyName provided is null or empty.
     */
    public BeanPropertyValueChangeConsumer(final String propertyName, final V propertyValue) {
        this(propertyName, propertyValue, false);
    }

    /**
     * Constructor which takes the name of the property to be changed, the new value to set the property to and a boolean which determines whether {@code null}
     * objects in the property path will generate an {@code IllegalArgumentException} or not.
     *
     * @param propertyName  The name of the property that will be updated with the value specified by {@code propertyValue}.
     * @param propertyValue The value that {@code propertyName} will be set to on the target object.
     * @param ignoreNull    Determines whether {@code null} objects in the property path will generate an {@code IllegalArgumentException} or not.
     * @throws IllegalArgumentException If the propertyName provided is null or empty.
     */
    public BeanPropertyValueChangeConsumer(final String propertyName, final V propertyValue, final boolean ignoreNull) {
        if (propertyName == null || propertyName.isEmpty()) {
            throw new IllegalArgumentException("propertyName cannot be null or empty");
        }
        this.propertyName = propertyName;
        this.propertyValue = propertyValue;
        this.ignoreNull = ignoreNull;
    }

    /**
     * Updates the target object provided using the property update criteria provided when this {@code BeanPropertyValueChangeClosure} was constructed. If any
     * object in the property path leading up to the target property is {@code null} then the outcome will be based on the value of the
     * {@code ignoreNull</code> attribute. By default, <code>ignoreNull} is
     * {@code false</code> and would result in an <code>IllegalArgumentException} if an object
     * in the property path leading up to the target property is {@code null}.
     *
     * @param object The object to be updated.
     * @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} and
     * {@code ignoreNull</code> is set to <code>false}.
     */
    @Override
    public void accept(final Object object) {

        try {
            PropertyUtils.setProperty(object, propertyName, propertyValue);
        } catch (final IllegalArgumentException e) {
            final String errorMsg = "Unable to execute Closure. Null value encountered in property path...";

            if (!ignoreNull) {
                throw new IllegalArgumentException(errorMsg, e);
            }
            log.warn(errorMsg, e);
        } catch (final IllegalAccessException e) {
            final String errorMsg = "Unable to access the property provided.";
            throw new IllegalArgumentException(errorMsg, e);
        } catch (final InvocationTargetException e) {
            final String errorMsg = "Exception occurred in property's getter";
            throw new IllegalArgumentException(errorMsg, e);
        } catch (final NoSuchMethodException e) {
            final String errorMsg = "Property not found";
            throw new IllegalArgumentException(errorMsg, e);
        }
    }

    /**
     * Returns the name of the property which will be updated when this {@code Closure} executes.
     *
     * @return The name of the property which will be updated when this {@code Closure} executes.
     */
    public String getPropertyName() {
        return propertyName;
    }

    /**
     * Returns the value that the property specified by {@code propertyName} will be updated to when this {@code Closure} executes.
     *
     * @return The value that the property specified by {@code propertyName} will be updated to when this {@code Closure} executes.
     */
    public V getPropertyValue() {
        return propertyValue;
    }

    /**
     * Returns the flag that determines whether {@code null} objects in the property path will generate an
     * {@code IllegalArgumentException</code> or not. If set to <code>true} then
     * if any objects in the property path leading up to the target property evaluate to
     * {@code null</code> then the <code>IllegalArgumentException} throw by
     * {@code PropertyUtils</code> will be logged but not re-thrown.  If set to <code>false} then
     * if any objects in the property path leading up to the target property evaluate to
     * {@code null</code> then the <code>IllegalArgumentException} throw by {@code PropertyUtils} will be logged and re-thrown.
     *
     * @return The flag that determines whether {@code null} objects in the property path will generate an {@code IllegalArgumentException} or not.
     */
    public boolean isIgnoreNull() {
        return ignoreNull;
    }
}