(Java) Fetch 1st N Headers of Search Results

Calls Search to get a message set, then downloads the 1st N messages in the message set. There are two equivalent ways of doing it: (1) iterate from 0 to N-1 and download each message individually, or (2) create a new message set that contains the 1st N messages and pass it to FetchHeaders. Both are demonstrated here.

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux Java Libs for Android

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 assumes 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() == false) {
        System.out.println(imap.lastErrorText());
        return;
        }

    int numFound = messageSet.get_Count();
    if (numFound == 0) {
        System.out.println("No messages found.");

        return;
        }

    // Get the 1st 10 messages in messageSet.
    int upperBound = 10;
    if (numFound < upperBound) {
        upperBound = numFound;
        }

    int i = 0;
    boolean bUid = messageSet.get_HasUids();
    while (i < upperBound) {

        CkEmail email = imap.FetchSingleHeader(messageSet.GetId(i),bUid);
        if (imap.get_LastMethodSuccess() == false) {
            System.out.println(imap.lastErrorText());

            return;

            }
        else {
            // Do whatever is needed with the email.. 
            // ....

            }

        i = i+1;
        }

    // Alternatively, create a new message set containing the 1st 10 message id's (UID's) 
    // from the search results message set:
    CkMessageSet firstTen = new CkMessageSet();

    for (i = 0; i <= upperBound - 1; i++) {
        firstTen.InsertId(messageSet.GetId(i));
        }

    // Download the 1st ten headers:
    CkEmailBundle bundle;
    bundle = imap.FetchHeaders(firstTen);
    if (imap.get_LastMethodSuccess() == false) {

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

    // Other examples show how to iterate over the emails contained within the bundle...

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