001/*
002 *  Copyright 2001-2013 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.beans;
017
018/**
019 * A query based on beans.
020 * <p>
021 * The query interface provides the simplest way to query beans.
022 * 
023 * @param <P>  the type of the property content
024 * @author Stephen Colebourne
025 */
026public interface BeanQuery<P> {
027
028    /**
029     * Queries a value from the specified bean.
030     * <p>
031     * This returns a value of some kind derived from the specified bean.
032     * This might be a property value or some other derived value.
033     * 
034     * @param bean  the bean to query, not null
035     * @return the value derived from the specified bean, may be null
036     * @throws ClassCastException if the bean is of an incorrect type
037     * @throws UnsupportedOperationException if unable to query
038     */
039    P get(Bean bean);
040
041}