Java

Fetch an IMAP Attachment into a BinData

Demonstrates the Chilkat Imap.FetchAttachmentBd method, which stores one attachment's bytes in a BinData object. The first argument is the Email, the second is the zero-based attachment index, and the third is the BinData, which is cleared before the operation. This example fetches the first attachment and prints its byte count.

Background: A BinData holds raw bytes, so it works for any attachment type — image, PDF, zip, and so on. From there you can save it, hash it, or hand it to another API expecting a byte buffer, all without touching the filesystem. Use the string/StringBuilder variants only when the attachment is known to be text.

Chilkat Java Downloads

Download Chilkat for Java

Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Email;
import com.chilkatsoft.chilkat2.Imap;

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates the Imap.FetchAttachmentBd method, which downloads one attachment's bytes into
        // a BinData object.  The 1st argument is the Email, the 2nd is the zero-based attachment
        // index, and the 3rd is the BinData (which is cleared first).
        //
        // The message is fetched headers-only, then the attachment is downloaded on demand.

        Imap imap = new Imap();

        imap.setSsl(true);
        imap.setPort(993);

        try {
            imap.connect("imap.example.com");

            imap.login("user@example.com", "myPassword");

            imap.selectMailbox("Inbox");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Fetch only the message headers.  Attachment bodies are NOT downloaded, but the ckx-imap-*
        // metadata describing the attachments is present, so the attachment info methods still work.
        boolean headersOnly = true;
        boolean useUid = false;
        int seqNum = 1;
        Email email = new Email();
        try {
            imap.fetchEmail(headersOnly, seqNum, useUid, email);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        int numAttach = imap.getMailNumAttach(email);
        if (numAttach > 0) {
            // Download just the first attachment's bytes from the server into a BinData.
            BinData bd = new BinData();
            try {
                imap.fetchAttachmentBd(email, 0, bd);
            } catch (ChilkatException e) {
                System.out.println(e.getLastErrorText());
                return;
            }

            System.out.println("Attachment size: " + bd.getNumBytes() + " bytes");
        }

        try {
            imap.disconnect();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }
    }
}