Mail.java

package com.robertlancer.supershare.util;

import com.google.api.client.repackaged.org.apache.commons.codec.binary.Base64;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.model.Message;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Properties;

public class Mail {

  /**
   * Send an email from the user's mailbox to its recipient.
   *
   * @param service Authorized Gmail API instance.
   * @param userId  User's email address. The special value "me"
   *                can be used to indicate the authenticated user.
   * @param email   Email to be sent.
   * @throws javax.mail.MessagingException
   * @throws java.io.IOException
   */
  public static void sendMessage(Gmail service, String userId, MimeMessage email)
    throws MessagingException, IOException {
    Message message = createMessageWithEmail(email);
    message = service.users().messages().send(userId, message).execute();

    System.out.println("Message id: " + message.getId());
    System.out.println(message.toPrettyString());
  }

  /**
   * Create a Message from an email
   *
   * @param email Email to be set to raw of message
   * @return Message containing base64 encoded email.
   * @throws java.io.IOException
   * @throws javax.mail.MessagingException
   */
  public static Message createMessageWithEmail(MimeMessage email) throws MessagingException, IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    email.writeTo(baos);
    String encodedEmail = Base64.encodeBase64URLSafeString(baos.toByteArray());
    Message message = new Message();
    message.setRaw(encodedEmail);
    return message;
  }

  /**
   * Create a MimeMessage using the parameters provided.
   *
   * @param to       Email address of the receiver.
   * @param from     Email address of the sender, the mailbox account.
   * @param subject  Subject of the email.
   * @param bodyText Body text of the email.
   * @return MimeMessage to be used to send email.
   * @throws javax.mail.MessagingException
   */
  public static MimeMessage createEmail(String to, String from, String subject,
                                        String bodyText) throws MessagingException {
    Properties props = new Properties();
    Session session = Session.getDefaultInstance(props, null);

    MimeMessage email = new MimeMessage(session);
    InternetAddress tAddress = new InternetAddress(to);
    InternetAddress fAddress = new InternetAddress(from);

    email.setFrom(new InternetAddress(from));
    email.addRecipient(javax.mail.Message.RecipientType.TO, new InternetAddress(to));
    email.setSubject(subject);
    email.setText(bodyText);
    return email;
  }
}