001/* $Id: SetPropertiesRuleProvider.java 992060 2010-09-02 19:09:47Z simonetripodi $
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements.  See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License.  You may obtain a copy of the License at
009 *
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.commons.digester.annotations.providers;
019
020import java.lang.reflect.Field;
021import java.util.HashMap;
022import java.util.Map;
023import java.util.Map.Entry;
024
025import org.apache.commons.digester.SetPropertiesRule;
026import org.apache.commons.digester.annotations.AnnotationRuleProvider;
027import org.apache.commons.digester.annotations.rules.SetProperty;
028
029/**
030 * Provides instances of {@code SetPropertiesRule}.
031 *
032 * @since 2.1
033 */
034public final class SetPropertiesRuleProvider implements AnnotationRuleProvider<SetProperty, Field, SetPropertiesRule> {
035
036    /**
037     * The data structure that stores the aliases.
038     */
039    private final Map<String, String> aliases = new HashMap<String, String>();
040
041    /**
042     * {@inheritDoc}
043     */
044    public void init(SetProperty annotation, Field element) {
045        this.addAlias(annotation, element);
046    }
047
048    /**
049     * Adds a new alias attribute/property name; if the attribute name is not
050     * specified, the alias will be considered as property name identity.
051     *
052     * @param annotation the {@link SetProperty} reference.
053     * @param element the annotated element reference.
054     */
055    public void addAlias(SetProperty annotation, Field element) {
056        String attributeName = annotation.attributeName();
057        String propertyName = element.getName();
058
059        if (attributeName.length() > 0) {
060            this.aliases.put(attributeName, propertyName);
061        } else {
062            this.aliases.put(propertyName, propertyName);
063        }
064    }
065
066    /**
067     * {@inheritDoc}
068     */
069    public SetPropertiesRule get() {
070        String[] attributeNames = new String[this.aliases.size()];
071        String[] propertyNames = new String[this.aliases.size()];
072
073        int i = 0;
074        for (Entry<String, String> alias : this.aliases.entrySet()) {
075            attributeNames[i] = alias.getKey();
076            propertyNames[i++] = alias.getValue();
077        }
078
079        return new SetPropertiesRule(attributeNames, propertyNames);
080    }
081
082}