getContent Error

I agree but still is there a way to capture the message? I tested the codes and

                  Part mp = message;
                  Object cnt= mp.getContent();

from here it error out. Usually the type is always "text/plain". So I am thinking if error out, is it possible to capture the message content in the catch (Exception) {
capture here.
}

or is better not to process the message at all?

                  if (cnt instanceof Multipart) {
                        ...
                        }

Are you sure that the message is not a non-text attachment?
see: http://java.sun.com/developer/onlineTraining/JavaMail/contents.html (Getting Attachments)

String disposition = part.getDisposition();
if (disposition == null) {
  // Check if plain
  MimeBodyPart mbp = (MimeBodyPart)part;
  if (mbp.isMimeType("text/plain")) {
    // Handle plain
  } else {
    // Special non-attachment cases here of
    // image/gif, text/html, ...
  }
...
}

>        if (cnt instanceof Multipart) {

You certainly should be checking what type the parts are, what does your code currently look like?

You can print out the className (for debugging: )  System.out.println(cnt.getClass().getName());

The code snippet provided above assumes content is MutliPart
and then you can apply traversal on its content by doing:

Multipart mp = (Multipart)message.getContent();

for (int i=0, n=multipart.getCount(); i<n; i++) {
  Part part = multipart.getBodyPart(i));

... apply the above logic
}

Heres an example for reading messages and their attachments

import java.io.*;
import java.util.Properties;
import javax.mail.*;
import javax.mail.internet.*;

public class GetParts {
  public static void main (String args[])
      throws Exception {
    String host = args[0];
    String username = args[1];
    String password = args[2];

    // Get session
    Session session = Session.getInstance(
      new Properties(), null);

    // Get the store
    Store store = session.getStore("pop3");
    store.connect(host, username, password);

    // Get folder
    Folder folder = store.getFolder("INBOX");
    folder.open(Folder.READ_ONLY);

    BufferedReader reader = new BufferedReader (
      new InputStreamReader(System.in));

    // Get directory
    Message message[] = folder.getMessages();
    for (int i=0, n=message.length; i<n; i++) {
       System.out.println(i + ": "
         + message[i].getFrom()[0]
         + "\t" + message[i].getSubject());

      System.out.println(
        "Do you want to get the content?
           [YES to read/QUIT to end]");
      String line = reader.readLine();
      if ("YES".equals(line)) {
        Object content = message[i].getContent();
        if (content instanceof Multipart) {
          handleMultipart((Multipart)content);
        } else {
          handlePart(message[i]);
        }
      } else if ("QUIT".equals(line)) {
        break;
      }
    }

    // Close connection
    folder.close(false);
    store.close();
  }
  public static void handleMultipart(Multipart multipart)
      throws MessagingException, IOException {
    for (int i=0, n=multipart.getCount(); i<n; i++) {
      handlePart(multipart.getBodyPart(i));
    }
  }
  public static void handlePart(Part part)
      throws MessagingException, IOException {
    String disposition = part.getDisposition();
    String contentType = part.getContentType();
    if (disposition == null) { // When just body
      System.out.println("Null: "  + contentType);
      // Check if plain
      if ((contentType.length() >= 10) && 
          (contentType.toLowerCase().substring(
           0, 10).equals("text/plain"))) {
        part.writeTo(System.out);
      } else { // Don't think this will happen
        System.out.println("Other body: " + contentType);
        part.writeTo(System.out);
      }
    } else if (disposition.equalsIgnoreCase(Part.ATTACHMENT)) {
      System.out.println("Attachment: " + part.getFileName() +
        " : " + contentType);
      saveFile(part.getFileName(), part.getInputStream());
    } else if (disposition.equalsIgnoreCase(Part.INLINE)) {
      System.out.println("Inline: " +
        part.getFileName() +
        " : " + contentType);
      saveFile(part.getFileName(), part.getInputStream());
    } else {  // Should never happen
      System.out.println("Other: " + disposition);
    }
  }
  public static void saveFile(String filename,
      InputStream input) throws IOException {
    if (filename == null) {
      filename = File.createTempFile("xx", ".out").getName();
    }
    // Do no overwrite existing file
    File file = new File(filename);
    for (int i=0; file.exists(); i++) {
      file = new File(filename+i);
    }
    FileOutputStream fos = new FileOutputStream(file);
    BufferedOutputStream bos = new BufferedOutputStream(fos);

    BufferedInputStream bis = new BufferedInputStream(input);
    int aByte;
    while ((aByte = bis.read()) != -1) {
      bos.write(aByte);
    }
    bos.flush();
    bos.close();
    bis.close();
  }
}