import java.util.*;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.Message.RecipientType;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.swing.JOptionPane;

public class GmailClient {

    private String userName;
    private String password;
    private String receivingHost;

    public void setAccountDetails(String userName,String password){

        this.userName=userName;//sender's email can also use as User Name
        this.password=password;

    }

    public void readGmail(){

        /*this will print subject of all messages in the inbox of sender@gmail.com*/

        this.receivingHost="imap.gmail.com";//for imap protocol

        Properties props2=System.getProperties();

        props2.setProperty("mail.store.protocol", "imaps");
        // I used imaps protocol here

        Session session2=Session.getDefaultInstance(props2, null);

            try {

                    Store store=session2.getStore("imaps");

                    store.connect(this.receivingHost,this.userName, this.password);

                    Folder folder=store.getFolder("INBOX");//get inbox

                    folder.open(Folder.READ_ONLY);//open folder only to read

                    Message message[]=folder.getMessages();

                    for(int i=0;i<message.length;i++){

                        //print subjects of all mails in the inbox

                        System.out.println(message[i].getSubject());

                        //anything else you want

                    }

                    //close connections

                    folder.close(true);

                    store.close();

            } catch (Exception e) {

                    System.out.println(e.toString());

            }

    }

    public static void main(String[] args) {

        String mailFrom=new String("sender@gmail.com");

        //Sender must be a Gmail Account holder

        String mailTo=new String("receiver@gmail.com");

        //but here you can send to any type of mail account

        String senderPassword=new String("1234");

        String senderUserName=new String("sender");

        //Mention your email subject and content

        String mailSubject=new String("Testing Mail");

        String mailText=new String("Have an Nice Day ...........!!!");

        //Create a GmailClient object

        GmailClient newGmailClient=new GmailClient();

        //Setting up account details

        newGmailClient.setAccountDetails(senderUserName, senderPassword);

        //Send mail

        newGmailClient.sendGmail(mailFrom, mailTo, mailSubject, mailText);

        //Receive mails

        newGmailClient.readGmail();

    }

}