Cannot Mail Subject

Question

why the subject is null?
can anyone help me. thanks!
The next is my program:
import javax.mail.FetchProfile;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.Store;
import com.sun.mail.pop3.POP3Message;
public class Reciever {
     public static void main(String[] args) throws Exception{
          Session session = Session.getInstance(System.getProperties());
          Store store = session.getStore("pop3");
          store.connect(args[0],args[1],args[2]);     
          Folder folder = store.getFolder("INBOX");
          folder.open(Folder.READ_WRITE);
          System.out.println(folder.exists());
          Message[] messages = folder.getMessages();
          FetchProfile fp = new FetchProfile();
          fp.add(FetchProfile.Item.ENVELOPE);
          fp.add(FetchProfile.Item.FLAGS);
          fp.add("X-mailer");
          folder.fetch(messages,fp);     
          for (int i = 0; i < messages.length; i++) {
               POP3Message me = (POP3Message)messages;                    
               me.writeTo(System.out);
               System.out.println(me.getSubject());     
          folder.close(true);
          store.close();
the result after run it:
This is a multi-part message in MIME format.
------=_NextPart_000_0039_01C356BF.8F621D20
Content-Type: text/plain;
     charset="gb2312"
Content-Transfer-Encoding: base64
VGhpcyBpcyBhIG1haWwgZnJvbSBDaGVuLg==
------=_NextPart_000_0039_01C356BF.8F621D20
Content-Type: text/html;
     charset="gb2312"
Content-Transfer-Encoding: base64
PCFET0NUWVBFIEhUTUwgUFVCTElDICItLy9XM0MvL0RURCBIVE1MIDQuMCBUcmFuc2l0aW9uYWwv
L0VOIj4NCjxIVE1MPjxIRUFEPg0KPE1FVEEgaHR0cC1lcXVpdj1Db250ZW50LVR5cGUgY29udGVu
dD0idGV4dC9odG1sOyBjaGFyc2V0PWdiMjMxMiI+DQo8TUVUQSBjb250ZW50PSJNU0hUTUwgNi4w
MC4yODAwLjExMDYiIG5hbWU9R0VORVJBVE9SPg0KPFNUWUxFPjwvU1RZTEU+DQo8L0hFQUQ+DQo8
Qk9EWSBiZ0NvbG9yPSNmZmZmZmY+DQo8RElWPjxGT05UIHNpemU9Mj5UaGlzIGlzIGEgbWFpbCBm
cm9tIENoZW4uPC9GT05UPjwvRElWPjwvQk9EWT48L0hUTUw+DQo=
------=_NextPart_000_0039_01C356BF.8F621D20--
null

Answer 1

Are you asking why the subject of an incoming message is null? Probably because the sender didn't put a subject on the message.
Or if that wasn't your question, ask it differently.