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 */ 017package org.apache.commons.configuration.beanutils; 018 019import 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 "layouts" 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 */ 048public 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}