IMAP quota and folder size

import com.sun.mail.imap.IMAPStore;
import org.junit.Test;

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

public class Main {

    @Test
    public void imap() throws MessagingException {
        Properties prop = System.getProperties();

        String host = "imap.gmail.com";

        String username = "user@gmail.com";
        String password = "some-password";

        prop.setProperty("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        prop.setProperty("mail.imap.host", host);
        prop.setProperty("mail.imap.port", "993");
        prop.setProperty("mail.imap.starttls.enable", "true");
        prop.setProperty("mail.imap.socketFactory.fallback", "false");
        //prop.setProperty("mail.debug", "true");

        Session ses = Session.getInstance(prop, null);
        Store store = ses.getStore("imap");
        store.connect(host, username, password);

        if (!IMAPStore.class.isInstance(store))
            throw new IllegalStateException("Is not IMAPStore");

        IMAPStore imapStore = (IMAPStore) store;
        Folder defaultFolder = imapStore.getDefaultFolder();

        this.printFolderInfo(imapStore, defaultFolder, 1);
    }

    private void printQuotaInfo(IMAPStore store, Folder folder) throws MessagingException {
        Quota[] quotas;

        try {
            quotas = store.getQuota(folder.getFullName());
        } catch (MessagingException e) {
            if (e.getMessage().contains(" NO [NONEXISTENT] Unknown folder:"))
                return;

            throw e;
        }

        for (Quota quota : quotas) {
            System.out.println(String.format("quotaRoot:'%s'", quota.quotaRoot));

            for (Quota.Resource resource : quota.resources) {
                System.out.println(String.format("name:'%s', limit:'%s', usage:'%s',",
                        resource.name, resource.limit, resource.usage));
            }
        }
    }

    private long printFolderInfo(IMAPStore store, Folder folder, int level) throws MessagingException {
        long sizeSum = 0;
        long sizeMessages = 0;

        try {
            folder.open(Folder.READ_ONLY);

            for (Message message : folder.getMessages())
                sizeSum = sizeSum + message.getSize();

            folder.close(false);
        } catch (MessagingException e) {
            if (e.getMessage().compareTo("folder cannot contain messages") != 0)
                throw e;
        }

        sizeMessages = sizeSum;

        for (Folder child : folder.list())
            sizeSum = sizeSum + this.printFolderInfo(store, child, level + 1);

        System.out.println("---");
        System.out.println(String.format("%s - folderFullName:'%s', folderSizeMessages:'%s', folderSizeSum:'%s'",
                level, folder.getFullName(), sizeMessages, sizeSum));

        this.printQuotaInfo(store, folder);

        return sizeSum;
    }

}