Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package io.github.lal872k.monotifier; import com.google.api.client.auth.oauth2.Credential; import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp; import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver; import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow; import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets; import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport; import com.google.api.client.http.HttpTransport; import com.google.api.client.json.JsonFactory; import com.google.api.client.json.jackson2.JacksonFactory; import com.google.api.client.util.Base64; import com.google.api.client.util.store.FileDataStoreFactory; import com.google.api.services.gmail.Gmail; import com.google.api.services.gmail.GmailScopes; import com.google.api.services.gmail.model.Message; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.Arrays; import java.util.List; import java.util.Properties; import javax.mail.MessagingException; import javax.mail.Session; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; /** * * @author L. Arthur Lewis II */ public class GMail { /** Application name. */ private static final String APPLICATION_NAME = "MO Notifications"; /** Directory to store user credentials for this application. */ private static final java.io.File DATA_STORE_DIR; /** Global instance of the {@link FileDataStoreFactory}. */ private static FileDataStoreFactory DATA_STORE_FACTORY; /** Global instance of the JSON factory. */ private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance(); /** Global instance of the HTTP transport. */ private static HttpTransport HTTP_TRANSPORT; /** Global instance of the scopes required by this quickstart. * * If modifying these scopes, delete your previously saved credentials * at ~/.credentials/gmail-java-quickstart */ private static final List<String> SCOPES = Arrays.asList(GmailScopes.GMAIL_SEND); private static Gmail gmail; static { DATA_STORE_DIR = new java.io.File(GDrive.getJarPath() + "credentials/gmail"); try { HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport(); DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR); } catch (Throwable t) { t.printStackTrace(); System.exit(1); } } /** * Creates an authorized Credential object. * @return an authorized Credential object. * @throws IOException */ private static Credential authorize() throws IOException { // Load client secrets. InputStream in = GMail.class.getResourceAsStream("client_secret.json"); GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in)); // Build flow and trigger user authorization request. GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES).setDataStoreFactory(DATA_STORE_FACTORY).setAccessType("offline").build(); Credential credential = new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()) .authorize("user"); System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath()); return credential; } /** * Build and return an authorized GMail client service. * @return an authorized GMail client service * @throws IOException */ private static Gmail getGmailService() throws IOException { Credential credential = authorize(); return new Gmail.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential).setApplicationName(APPLICATION_NAME) .build(); } public static void connectGmail() throws IOException { System.out.println("Connecting to Gmail..."); gmail = getGmailService(); } /** * 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 the MimeMessage to be used to send email * @throws 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); email.setFrom(new InternetAddress(from)); email.addRecipient(javax.mail.Message.RecipientType.TO, new InternetAddress(to)); email.setSubject(subject); email.setText(bodyText); return email; } /** * Create a message from an email. * * @param emailContent Email to be set to raw of message * @return a message containing a base64url encoded email * @throws IOException * @throws MessagingException */ public static Message createMessageWithEmail(MimeMessage emailContent) throws MessagingException, IOException { ByteArrayOutputStream buffer = new ByteArrayOutputStream(); emailContent.writeTo(buffer); byte[] bytes = buffer.toByteArray(); String encodedEmail = Base64.encodeBase64URLSafeString(bytes); Message message = new Message(); message.setRaw(encodedEmail); return message; } /** * 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 emailContent Email to be sent. * @return The sent message * @throws MessagingException * @throws IOException */ public static Message sendMessage(Gmail service, String userId, MimeMessage emailContent) throws MessagingException, IOException { Message message = createMessageWithEmail(emailContent); message = service.users().messages().send(userId, message).execute(); System.out.println("Message sent with id: " + message.getId()); return message; } public static boolean sendEmail(String recipient, String subject, String message) throws IOException { try { sendMessage(gmail, "me", createEmail(recipient, "monotifications1864@gmail.com", subject, message)); return true; } catch (MessagingException ex) { ex.printStackTrace(); return false; } } }