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    
018    package org.apache.commons.codec;
019    
020    /**
021     * Provides the highest level of abstraction for Decoders.
022     * <p>
023     * This is the sister interface of {@link Encoder}. All Decoders implement this common generic interface.
024     * Allows a user to pass a generic Object to any Decoder implementation in the codec package.
025     * <p>
026     * One of the two interfaces at the center of the codec package.
027     *
028     * @version $Id: Decoder.html 889935 2013-12-11 05:05:13Z ggregory $
029     */
030    public interface Decoder {
031    
032        /**
033         * Decodes an "encoded" Object and returns a "decoded" Object. Note that the implementation of this interface will
034         * try to cast the Object parameter to the specific type expected by a particular Decoder implementation. If a
035         * {@link ClassCastException} occurs this decode method will throw a DecoderException.
036         *
037         * @param source
038         *            the object to decode
039         * @return a 'decoded" object
040         * @throws DecoderException
041         *             a decoder exception can be thrown for any number of reasons. Some good candidates are that the
042         *             parameter passed to this method is null, a param cannot be cast to the appropriate type for a
043         *             specific encoder.
044         */
045        Object decode(Object source) throws DecoderException;
046    }
047