(Java) Read IMAP Email Headers

Call FetchHeaders to download only the email headers.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkImap imap = new CkImap();

    // Connect to an IMAP server.
    // Use TLS
    imap.put_Ssl(true);
    imap.put_Port(993);
    boolean success = imap.Connect("imap.someMailServer.com");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Login
    success = imap.Login("****","****");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox");
    if (success != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    CkMessageSet messageSet;
    // We can choose to fetch UIDs or sequence numbers.
    boolean fetchUids = true;
    // Get the message IDs of all the emails in the mailbox
    messageSet = imap.Search("ALL",fetchUids);
    if (imap.get_LastMethodSuccess() != true) {
        System.out.println(imap.lastErrorText());
        return;
        }

    // When downloading headers, each email object contains
    // (obviously) the headers, but the body will be missing.
    // Also, attachments will not be included.  However, it is
    // possible to get information about the attachments
    // as well as the complete size of the email.
    CkEmailBundle bundle;
    bundle = imap.FetchHeaders(messageSet);
    if (imap.get_LastMethodSuccess() != true) {

        System.out.println(imap.lastErrorText());
        return;
        }

    // Loop over the email objects and display information
    // about each:
    int i;
    for (i = 0; i <= bundle.get_MessageCount() - 1; i++) {
        CkEmail email;
        email = bundle.GetEmail(i);

        // Display the From and Subject
        System.out.println(email.ck_from());
        System.out.println(email.subject());

        // Display the recipients:
        int j;
        String name;
        String addr;
        for (j = 0; j <= email.get_NumTo() - 1; j++) {
            name = email.getToName(j);
            addr = email.getToAddr(j);
            System.out.println(name + ", " + addr);
            }

        for (j = 0; j <= email.get_NumCC() - 1; j++) {
            name = email.getCcName(j);
            addr = email.getCcAddr(j);
            System.out.println(name + ", " + addr);
            }

        // Show the total size of the email, including body and attachments:
        System.out.println(email.get_Size());

        // When a full email is downloaded, we would use the
        // email.NumAttachments property in conjunction with the
        // email.GetMailAttach* methods.
        // However, when an email object contains only the header,
        // we need to access the attachment info differently:
        int numAttach = imap.GetMailNumAttach(email);
        for (j = 0; j <= numAttach - 1; j++) {
            System.out.println(imap.getMailAttachFilename(email,j));
            int attachSize = imap.GetMailAttachSize(email,j);
            System.out.println("    size = " + attachSize + " bytes");
            }

        System.out.println("--");

        }

    // Disconnect from the IMAP server.
    success = imap.Disconnect();
  }
}