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    package org.apache.camel.component.mail;
018    
019    /**
020     * Resolver to determine Content-Type for file attachments.
021     * <p/>
022     * Strategy introduced to work around mail providers having problems with this such as geronimo mail jars.
023     * <p/>
024     * Note using SUN mail jar have no problem with resolving Content-Type based on file attachments. This resolver
025     * is thus only needed to work around mail providers having bugs or when you a new mime type is unknown by the
026     * mail provider allowing you to determine it.
027     *
028     * @version $Revision: 12812 $
029     */
030    public interface ContentTypeResolver {
031    
032        /**
033         * Resolves the mime content-type based on the attachment file name.
034         * <p/>
035         * Return <tt>null</tt> if you cannot resolve a content type or want to rely on the mail provider
036         * to resolve it for you.
037         * <p/>
038         * The returned value should only be the mime part of the ContentType header, for example:
039         * <tt>image/jpeg</tt> should be returned. Camel will add the remaining <tt>; name=FILENAME</tt>.
040         *
041         * @param fileName  the attachment file name
042         * @return the Content-Type or <tt>null</tt> to rely on the mail provider
043         */
044        String resolveContentType(String fileName);
045    }