connect to Gmail Imap using javamail

import java.util.Properties;

import javax.mail.Folder;

import javax.mail.Message;

import javax.mail.Session;

import javax.mail.Store;

public class Program {

    public static void main(String[] args) throws Exception {

        String host = "imap.gmail.com";

        int port = 993;

        String user = "[email protected]";

        String password = "xxxxx";

        String target_folder = "INBOX";

        Properties props = System.getProperties();

        Session sess = Session.getInstance(props, null);

//        sess.setDebug(true);

        Store st = sess.getStore("imaps");

        st.connect(host, port, user, password);

        Folder fol = st.getFolder(target_folder);

        if (fol.exists()) {

            for (Folder f : fol.list()) {

                System.out.println(f.getName());

            }

            fol.open(Folder.READ_ONLY);

            for (Message m : fol.getMessages()) {

                System.out.printf("%s - %d/n", m.getSubject(), m.getSize());

            }

            fol.close(false);

        } else {

            System.out.printf("%s is not exist.", target_folder);

        }

        st.close();

    }

}