Email sending authentication of username password

Question

I am developing an application which send the e-mail from it. To send e mail I used the code which is with out intent code. As it is the need of application. The code I used is as follows :

import java.util.Date;
import java.util.Properties;
import javax.activation.CommandMap;
import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.activation.MailcapCommandMap;
import javax.mail.BodyPart;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;


public class Mail extends javax.mail.Authenticator {
    private String _user;
    private String _pass;

    private String[] _to;
    private String _from;

    private String _port;
    private String _sport;

    private String _host;

    private String _subject;
    private String _body;

    private boolean _auth;

    private boolean _debuggable;

    private Multipart _multipart;


    public Mail() {
        _host = "smtp.gmail.com"; // default smtp server
        _port = "465"; // default smtp port
        _sport = "465"; // default socketfactory port

        _user = ""; // username
        _pass = ""; // password
        _from = ""; // email sent from
        _subject = ""; // email subject
        _body = ""; // email body

        _debuggable = false; // debug mode on or off - default off
       _auth = true; // smtp authentication - default on

       _multipart = new MimeMultipart();

       // There is something wrong with MailCap, javamail can not find a handler for the multipart/mixed part, so this bit needs to be added.
       MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
       mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");
       mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
       mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
       mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
       mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
       CommandMap.setDefaultCommandMap(mc);
   }

   public Mail(String user, String pass) {
       this();

       _user = user;
       _pass = pass;
   }

   public boolean send() throws Exception {
       Properties props = _setProperties();

       if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) {
           Session session = Session.getInstance(props, this);

           MimeMessage msg = new MimeMessage(session);

           msg.setFrom(new InternetAddress(_from));

           InternetAddress[] addressTo = new InternetAddress[_to.length];
           for (int i = 0; i < _to.length; i++) {
               addressTo[i] = new InternetAddress(_to[i]);
           }
       msg.setRecipients(MimeMessage.RecipientType.TO, addressTo);

           msg.setSubject(_subject);
           msg.setSentDate(new Date());

           // setup message body
           BodyPart messageBodyPart = new MimeBodyPart();
           messageBodyPart.setText(_body);
           _multipart.addBodyPart(messageBodyPart);

           // Put parts in message
           msg.setContent(_multipart);

           // send email
           Transport.send(msg);

           return true;
       } else {
           return false;
       }
    }

    public void addAttachment(String filename) throws Exception {
        BodyPart messageBodyPart = new MimeBodyPart();
        DataSource source = new FileDataSource(filename);
        messageBodyPart.setDataHandler(new DataHandler(source));
        messageBodyPart.setFileName(filename);

        _multipart.addBodyPart(messageBodyPart);
    }

    @Override
    public PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(_user, _pass);
    }

    private Properties _setProperties() {
        Properties props = new Properties();

        props.put("mail.smtp.host", _host);

        if(_debuggable) {
            props.put("mail.debug", "true");
        }

        if(_auth) {
            props.put("mail.smtp.auth", "true");
        }

        props.put("mail.smtp.port", _port);
        props.put("mail.smtp.socketFactory.port", _sport);
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");

        return props;
    }

    // the getters and setters
    public String getBody() {
        return _body;
    }

    public void setBody(String _body) {
        this._body = _body;
    }

    public String[] get_to() {
        return _to;
    }

    public void set_to(String[] _to) {
        this._to = _to;
    }

    public String get_from() {
        return _from;
    }

    public void set_from(String _from) {
        this._from = _from;
    }

    public String get_subject() {
        return _subject;
    }

    public void set_subject(String _subject) {
        this._subject = _subject;
    } 
}

I called this class by the code as :

Mail m = new Mail("UserName.gmail.com", "Password");

String[] toArr = {"demo.gmail.com"};
m.set_to(toArr);
m.set_from("UserName.gmail.com");
m.set_subject(sub);
m.setBody(finalbody);

try {
    if(m.send()) {
        Toast.makeText(EMailActivity.this, "Email was sent successfully.", Toast.LENGTH_LONG).show();
    } else {                    
    Toast.makeText(EMailActivity.this, "Email was not sent.", Toast.LENGTH_LONG).show();
    }
} catch(Exception e) {
}

I also included three required jar files as :

activation.jar
additionnal.jar
mail.jar

Now the issue is that : When i enter wrong user name or password in line as -

Mail m = new Mail("UserName.gmail.com", "Password");

Than no mail is sent and screen locks. User cant move farther as the screen is lock. It is due to the mail is not send.

So is there any method by which I can authenticate the user name and password entered by user. Or if the user name or password is wrong then how can I prevent the screen from lock and do any action after that.

Answer 1

No there is no such type of method or api present now.