Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can * obtain a copy of the License at * https://oss.oracle.com/licenses/CDDL+GPL-1.1 * or LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at LICENSE.txt. * * GPL Classpath Exception: * Oracle designates this particular file as subject to the "Classpath" * exception as provided by Oracle in the GPL Version 2 section of the License * file that accompanied this code. * * Modifications: * If applicable, add the following below the License Header, with the fields * enclosed by brackets [] replaced by your own identifying information: * "Portions Copyright [year] [name of copyright owner]" * * Contributor(s): * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package javax.mail; /** * The context in which a piece of Message content is contained. A * <code>MessageContext</code> object is returned by the * <code>getMessageContext</code> method of the * <code>MessageAware</code> interface. <code>MessageAware</code> is * typically implemented by <code>DataSources</code> to allow a * <code>DataContentHandler</code> to pass on information about the * context in which a data content object is operating. * * @see javax.mail.MessageAware * @see javax.activation.DataSource * @see javax.activation.DataContentHandler * @since JavaMail 1.1 */ public class MessageContext { private Part part; /** * Create a MessageContext object describing the context of the given Part. * * @param part the Part */ public MessageContext(Part part) { this.part = part; } /** * Return the Part that contains the content. * * @return the containing Part, or null if not known */ public Part getPart() { return part; } /** * Return the Message that contains the content. * Follows the parent chain up through containing Multipart * objects until it comes to a Message object, or null. * * @return the containing Message, or null if not known */ public Message getMessage() { try { return getMessage(part); } catch (MessagingException ex) { return null; } } /** * Return the Message containing an arbitrary Part. * Follows the parent chain up through containing Multipart * objects until it comes to a Message object, or null. * * @return the containing Message, or null if none * @see javax.mail.BodyPart#getParent * @see javax.mail.Multipart#getParent */ private static Message getMessage(Part p) throws MessagingException { while (p != null) { if (p instanceof Message) return (Message) p; BodyPart bp = (BodyPart) p; Multipart mp = bp.getParent(); if (mp == null) // MimeBodyPart might not be in a MimeMultipart return null; p = mp.getParent(); } return null; } /** * Return the Session we're operating in. * * @return the Session, or null if not known */ public Session getSession() { Message msg = getMessage(); return msg != null ? msg.getSession() : null; } }