Messages and Parts - JavaMail API - page 58

Most of the methods you need in the MimeBodyPart and BodyPart classes are the ones
you're already familiar with from the Part interface, methods such as setContent()
and setDataHandler() . There are also three methods to read the contents of a
Multipart object:
public String getContentType ()
public int getCount () throws MessagingException
public BodyPart getBodyPart ( int index )
throws IndexOutOfBoundsException , MessagingException
The getContentType() method returns the MIME media type of the entire
Multipart , which is typically something like multipart/mixed or multipart/
alternative . This is not the same as the MIME types of the individual parts, which are
something like text/plain or image/gif .
The getCount() method returns the number of parts in this Multipart . The getBody
Part() method returns a particular part. Parts are numbered starting at 0, like the
components of an array. Example 7-5 is very similar to Example 7-4 , AllHeader
Client . However, Example 7-5 adds the necessary code to handle the body of the mes‐
sage. If the message is a single-part message, it's simply printed on System.out ; but if
the message has multiple parts, each part is handled separately. If the part has a multipart
content type itself, processMultipart() is called recursively. If the part has no filename,
does not have the disposition Part.ATTACHMENT , and has MIME type text/plain , it's
assumed to be an in-line message and is printed on System.out . Otherwise, it's assumed
to be an attachment and is saved into an appropriate file. If necessary, the static
File.createTempFile() method generates a reasonable name for the file.
Example 7-5. A mail client that handles multipart messages with attached files
import java.util.* ;
import java.io.* ;
import javax.mail.* ;
public class AllPartsClient {
public static void main ( String [] args ) {
if ( args . length == 0 ) {
System . err . println (
"Usage: java AllPartsClient protocol://username@host:port/foldername" );
return ;
}
URLName server = new URLName ( args [ 0 ]);
try {
Session session = Session . getInstance ( new Properties (),
new MailAuthenticator ( server . getUsername ()));
// Connect to the server and open the folder