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     */
016    package 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     */
026    public 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    }