text: /*
   * Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
   *
   * This program and the accompanying materials are made available under the
   * terms of the Eclipse Public License v. 2.0, which is available at
   * http://www.eclipse.org/legal/epl-2.0.
   *
   * This Source Code may also be made available under the following Secondary
   * Licenses when the conditions for such availability set forth in the
   * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
   * version 2 with the GNU Classpath Exception, which is available at
   * https://www.gnu.org/software/classpath/license.html.
   *
   * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
   */
  
  package jakarta.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 jakarta.mail.MessageAware
   * @see jakarta.activation.DataSource
   * @see jakarta.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 jakarta.mail.BodyPart#getParent
       * @see jakarta.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;
      }
  }
  