如何使用JavaMail检查邮件UID是否存在？

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

public class CheckEmailUID {
    public static void main(String[] args) {
        String host = "your-mail-server";
        String username = "your-username";
        String password = "your-password";
        String folderName = "INBOX";
        long targetUID = 12345;

        Properties props = new Properties();
        props.setProperty("mail.store.protocol", "imap");
        props.setProperty("mail.imap.host", host);

        try {
            Session session = Session.getInstance(props);
            Store store = session.getStore();
            store.connect(host, username, password);

            Folder folder = store.getFolder(folderName);
            folder.open(Folder.READ_ONLY);

            Message[] messages = folder.getMessagesByUID(targetUID, targetUID);
            if (messages.length > 0) {
                System.out.println("UID " + targetUID + " exists.");
            } else {
                System.out.println("UID " + targetUID + " does not exist.");
            }

            folder.close(false);
            store.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}