Retrieve the plain text and HTML content in the body of an email message using a recursive method

Create a recursive method to retrieve all the parts of the body of an email message including plain text and HTML.

  1. Import the required classes and interfaces.
    import net.rim.blackberry.api.mail.MimeBodyPart;
    import net.rim.blackberry.api.mail.Multipart;
    import net.rim.blackberry.api.mail.SupportedAttachmentPart;
    import net.rim.blackberry.api.mail.TextBodyPart;
    import net.rim.blackberry.api.mail.UnsupportedAttachmentPart;
    
  2. Create the method signature for the recursive method.
    void findEmailBody(Object obj) {...}
    
  3. Create local variables that indicate if the BlackBerry® Attachment Service supports the message attachment type.
    boolean _hasSupportedAttachment; 
    boolean _hasUnsupportedAttachment;
    
  4. Initialize the local variables.
    _hasSupportedAttachment = false; 
    _hasUnsupportedAttachment = false;
    
  5. If the method parameter is a Multipart object, the object has multiple BodyPart objects. On each BodyPart object, invoke the recursive method that searches through the body of an email message.
    if(obj instanceof Multipart)
    { 
       _Multipart mp = (Multipart)obj;
    
       //Extract all of the parts within the Multipart message.
       for(int count=0; count < mp.getCount(); ++count)
       { 
          findEmailBody(mp.getBodyPart(count));
       }
    }
    
  6. If the BodyPart object is a TextBodyPart, retrieve the plain text body of the message.
    else if (obj instanceof TextBodyPart)
    {
       //This message only has a text body.
       TextBodyPart tbp = (TextBodyPart) obj; 
       readEmailBody(tbp);
    }
    
  7. Check if the BodyPart object is a MimeBodyPart.
    else if (obj instanceof MimeBodyPart) {...}
    
  8. If the BodyPart object is a MimeBodyPart, perform the following actions:
    1. Cast the BodyPart object as a MimeBodyPart.
      MimeBodyPart mbp = (MimeBodyPart) obj;  
      
    2. If the MimeBodyPart object does not contain attachments, retrieve the body of the message using the MimeBodyPart object as a parameter.
      if (mbp.getContentType().indexOf(ContentType.TYPE_TEXT_HTML_STRING) != -1)
      {
         readEmailBody(mbp);
      }
      
    3. If the MimeBodyPart object does contain attachments, invoke a method that retrieves the body of the message.
      else if 
         (mbp.getContentType().equals(ContentType.TYPE_MULTIPART_MIXED_STRING) || 
            mbp.getContentType().equals(ContentType.TYPE_MULTIPART_ALTERNATIVE_STRING))
      {
         findEmailBody(mbp.getContent());
      }
      
  9. If the BodyPart is an attachment that the BlackBerry Attachment Service supports, change the appropriate local variable to true.
    else if (obj instanceof SupportedAttachmentPart)
    {
       _hasSupportedAttachment = true;
    } 
    
  10. If the BodyPart is an attachment that the BlackBerry Attachment Service does not support, change the appropriate local variable to true.
    else if (obj instanceof UnsupportedAttachmentPart)
    {
       _hasUnsupportedAttachment = true;
    } 
    

Code sample: Retrieving the content of an email message

private void findEmailBody(Object obj)
{
   //Reset the attachment flags.
   _hasSupportedAttachment = false;
   _hasUnsupportedAttachment = false;

   if(obj instanceof Multipart)
   {
      Multipart mp = (Multipart)obj;
    
      for(int count=0; count < mp.getCount(); ++count)
      {
        findEmailBody(mp.getBodyPart(count));
      }
   }
    
   else if (obj instanceof TextBodyPart)
   {
      TextBodyPart tbp = (TextBodyPart) obj;
      readEmailBody(tbp);
   }

   else if (obj instanceof MimeBodyPart)
   {
      MimeBodyPart mbp = (MimeBodyPart)obj;
      if (mbp.getContentType().indexOf(ContentType.TYPE_TEXT_HTML_STRING) != -1)
      {
        readEmailBody(mbp);
      }
   }

   else if (mbp.getContentType().equals(ContentType.TYPE_MULTIPART_MIXED_STRING) ||
   mbp.getContentType().equals(ContentType.TYPE_MULTIPART_ALTERNATIVE_STRING))
   {    
      //The message has attachments or we are at the top level of the message.
      //Extract all of the parts within the MimeBodyPart message.
      findEmailBody(mbp.getContent());
   }
   
   else if (obj instanceof SupportedAttachmentPart)  
   {
      _hasSupportedAttachment = true;
   }

   else if (obj instanceof UnsupportedAttachmentPart) 
   {
      _hasUnsupportedAttachment = true;
   }
}

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