001    /*
002     *  Copyright 2004 The Apache Software Foundation
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.apache.commons.convert;
017    
018    /**
019     * Defines a class that can convert one object to an object of another type.
020     * <p>
021     * All configuration data for the conversion must be set on the converter
022     * separately.
023     *
024     * @author Stephen Colebourne
025     * @version $Id: Conversion.java 155441 2005-02-26 13:19:22Z dirkv $
026     * @since 1.0
027     */
028    public interface Conversion {
029    
030        /**
031         * Convert the specified input object into an output object
032         * of the another type.
033         *
034         * @param value  the value to be converted, read only, may be null
035         * @param converter  the converter being used, not null
036         * @return the converted value
037         * @throws Exception if conversion fails, use ConversionException if creating
038         *  a new exception, otherwise just allow exceptions to be thrown
039         */
040        Object convert(Object value, Converter converter) throws Exception;
041    
042        /**
043         * The type to convert from.
044         *
045         * @return the Class object representing the class to convert to
046         */
047        Class getFromType();
048    
049        /**
050         * The type to convert to.
051         *
052         * @return the Class object representing the class to convert from
053         */
054        Class getToType();
055    
056    }