Java

Download an IMAP Message Set

Demonstrates how to read a set of IMAP emails. Java

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[])
  {
    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    CkImap imap = new CkImap();

    //  Connect using TLS.
    imap.put_Ssl(true);
    imap.put_Port(993);
    success = imap.Connect("imap.example.com");
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    //  Authenticate
    success = imap.Login("email_account_login","email_account_password");
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

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

    //  Search for messages with the word "test" in the subject.
    boolean fetchUids = true;

    CkMessageSet messageSet = new CkMessageSet();
    success = imap.QueryMbx("Subject test",fetchUids,messageSet);
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    //  Download the messages in a single call to FetchMsgSet.
    //  
    //  This only makes sense if the number of emails to be downloaded is not too large.  
    //  For example, you wouldn't want to download 10000 emails in a single call to FetchMsgSet.
    //  Why? For two reasons:  (1) It could potentially cause an out-of-memory condition, and 
    //  (2) it would take an extremely large amount of time.  The longer the amount of time,
    //  the greater the likelihood of some kind of external networking or server problem occuring,
    //  and if it happens, then you would need to re-download everything from the beginning again.
    //  For large numbers of emails, it's better to loop over the emails in the message set
    //  and download/process one at a time as shown here: Download IMAP Messages One at a Time
    //  Downloading one message at a time makes it possible to resume the downloads rather than restart the entire operation all over again.

    //  If the message set is reasonable in size, you can download all at once using FetchMsgSet:

    System.out.println("Number of messages = " + messageSet.get_Count());

    CkEmailBundle bundle = new CkEmailBundle();
    boolean headersOnly = false;
    success = imap.FetchMsgSet(headersOnly,messageSet,bundle);
    if (success == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    //  Display the Subject and From of each email.
    CkEmail email = new CkEmail();
    int i = 0;
    int numEmails = bundle.get_MessageCount();
    while (i < numEmails) {
        bundle.EmailAt(i,email);

        System.out.println(email.getHeaderField("Date"));
        System.out.println(email.subject());
        System.out.println(email.ck_from());
        System.out.println("--");
        i = i+1;
        }
  }
}