MailServiceHelper Failed while sending email java.lang.NullPointerException

Question

Hi guys,
I am trying to send email with Adobe CQ API.
But i am getting a nullpointer exception at this line:  MsgGateway.send(htmlEmail);    
This is my method that i am using to send.
import com.day.cq.mailer.MessageGateway;
import com.day.cq.mailer.MessageGatewayService;
import javax.mail.internet.InternetAddress;
   public boolean sendHtmlEmail(SlingHttpServletRequest sling,
            String fromMailAdress, List<String> recepientmailAddress,
            String emailSubject, String htmlbodyMail) {
        HtmlEmail htmlEmail = new HtmlEmail();
        List<InternetAddress> emailAddress = new ArrayList<InternetAddress>();
        try {
            for (String recipient : recepientmailAddress) {
                if (!StringUtil.isEmpty(recipient)) {
                    emailAddress.add(new InternetAddress(recipient));
                    log.error(recipient);
            if (!StringUtil.isEmpty(fromMailAdress)) {
                htmlEmail.setFrom(fromMailAdress);
            htmlEmail.setTo(emailAddress);
            htmlEmail.setSubject(emailSubject);
            htmlEmail.setHtmlMsg(htmlbodyMail);
            htmlEmail.setCharset("utf-8");
            MessageGatewayService MsgService = getMessageGateWayService(sling);
            MessageGateway<HtmlEmail> MsgGateway = MsgService.getGateway(HtmlEmail.class);
            MsgGateway.send(htmlEmail);   //nullpointer exception caught here        
            return true;
        } catch (Exception e) {
            log.error("Failed while sending email", e);
        return false;
I have checked to ensure the bundle com.day.cq.cq-mail and my own bundle is running .
I am also sure that 'htmlEmail' is not null by retrieving the email subject via .getSubject and it did return me the subject.
I do not understand what is returning the nullpointerexception.
Thanks in advance !

Answer 1

The MessageGateway instance (MessageGateway<HtmlEmail> MsgGateway) is null therby throwing a null pointer.
Instead of instanciating msgGateway as :
MessageGatewayService MsgService = getMessageGateWayService(sling);
MessageGateway<HtmlEmail> MsgGateway = MsgService.getGateway(HtmlEmail.class);
Inject your MessageGateway as:
@Reference
private MessageGateway<HtmlEmail> msgGateway;
and then call send on msgGateway as msgGateway.send(htmlEmail)
~ Aditya