    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    package org.apache.commons.configuration.beanutils;
    018
    019    import java.util.Map;
    020
    021    /**
    022     * <p>
    023     * Definition of an interface for declaring a bean in a configuration file.
    024     * </p>
    025     * <p>
    026     * Commons Configurations allows to define beans (i.e. simple Java objects) in
    027     * configuration files, which can be created at runtime. This is especially
    028     * useful if you program against interfaces and want to define the concrete
    029     * implementation class is a configuration file.
    030     * </p>
    031     * <p>
    032     * This interface defines methods for retrieving all information about a bean
    033     * that should be created from a configuration file, e.g. the bean's properties
    034     * or the factory to use for creating the instance. With different
    035     * implementations different &quot;layouts&quot; of bean declarations can be
    036     * supported. For instance if an XML configuration file is used, all features of
    037     * XML (e.g. attributes, nested elements) can be used to define the bean. In a
    038     * properties file the declaration format is more limited. The purpose of this
    039     * interface is to abstract from the concrete declaration format.
    040     * </p>
    041     *
    042     * @since 1.3
    043     * @author <a
    044     * href="http://commons.apache.org/configuration/team-list.html">Commons
    045     * Configuration team</a>
    046     * @version $Id: BeanDeclaration.java 1208756 2011-11-30 20:37:32Z oheger $
    047     */
    048    public interface BeanDeclaration
    049    {
    050        /**
    051         * Returns the name of the {@code BeanFactory} that should be used
    052         * for creating the bean instance. This can be <b>null</b>, then a default
    053         * factory will be used.
    054         *
    055         * @return the name of the bean factory
    056         */
    057        String getBeanFactoryName();
    058
    059        /**
    060         * Here an arbitrary object can be returned that will be passed to the bean
    061         * factory. Its meaning is not further specified. The purpose of this
    062         * additional parameter is to support a further configuration of the bean
    063         * factory that can be placed directly at the bean declaration.
    064         *
    065         * @return a parameter for the bean factory
    066         */
    067        Object getBeanFactoryParameter();
    068
    069        /**
    070         * Returns the name of the bean class, from which an instance is to be
    071         * created. This value must be defined unless a default class is provided
    072         * for the bean creation operation.
    073         *
    074         * @return the name of the bean class
    075         */
    076        String getBeanClassName();
    077
    078        /**
    079         * Returns a map with properties that should be initialized on the newly
    080         * created bean. The map's keys are the names of the properties; the
    081         * corresponding values are the properties' values. The return value can be
    082         * <b>null</b> if no properties should be set.
    083         *
    084         * @return a map with properties to be initialized
    085         */
    086        Map<String, Object> getBeanProperties();
    087
    088        /**
    089         * Returns a map with declarations for beans that should be set as
    090         * properties of the newly created bean. This allows for complex
    091         * initialization scenarios: a bean for a bean that contains complex
    092         * properties (e.g. other beans) can have nested declarations for defining
    093         * these complex properties. The returned map's key are the names of the
    094         * properties to initialize. The values are either {@code BeanDeclaration}
    095         * implementations or collections thereof. They will be treated like this
    096         * declaration (in a* recursive manner), and the resulting beans are
    097         * assigned to the corresponding properties.
    098         *
    099         * @return a map with nested bean declarations
    100         */
    101        Map<String, Object> getNestedBeanDeclarations();
    102    }