feat: add mail sending util (#87)

pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>com.bigboxer23</groupId>
   <artifactId>utils</artifactId>
-  <version>2.0.28</version>
+  <version>2.0.29</version>
 
   <name>utils</name>
   <!-- FIXME change it to the project's website -->
@@ -50,6 +50,11 @@
       <artifactId>moshi</artifactId>
       <version>1.15.1</version>
     </dependency>
+    <dependency>
+      <groupId>com.sun.mail</groupId>
+      <artifactId>javax.mail</artifactId>
+      <version>1.6.2</version>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>

src/main/java/com/bigboxer23/utils/command/RetryingCommand.java

@@ -9,7 +9,8 @@ public class RetryingCommand {
 	private static final Logger logger = LoggerFactory.getLogger(RetryingCommand.class);
 
 	/**
-	 * Run a command and retry it after a pause. Can define pause length in seconds, and number of retry attempts
+	 * Run a command and retry it after a pause. Can define pause length in seconds, and number of
+	 * retry attempts
 	 *
 	 * @param command command to run
 	 * @param identifier identifier to log on failures

src/main/java/com/bigboxer23/utils/mail/MailSender.java

@@ -0,0 +1,70 @@
+package com.bigboxer23.utils.mail;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+import javax.activation.DataHandler;
+import javax.activation.FileDataSource;
+import javax.mail.*;
+import javax.mail.internet.InternetAddress;
+import javax.mail.internet.MimeBodyPart;
+import javax.mail.internet.MimeMessage;
+import javax.mail.internet.MimeMultipart;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/** */
+public class MailSender {
+
+	private static final Logger logger = LoggerFactory.getLogger(MailSender.class);
+
+	private static Session mailSession;
+
+	public static void sendGmail(
+			String toEmail, String fromEmail, String sendingPW, String subject, String body, List<File> files) {
+		if (fromEmail == null || sendingPW == null || toEmail == null) {
+			logger.info("Not sending email, not configured");
+			return;
+		}
+		if (mailSession == null) {
+			Properties properties = new Properties();
+			properties.put("mail.smtp.auth", "true");
+			properties.put("mail.smtp.starttls.enable", "true");
+			properties.put("mail.smtp.host", "smtp.gmail.com");
+			properties.put("mail.smtp.port", "587");
+			mailSession = Session.getInstance(properties, new Authenticator() {
+				@Override
+				protected PasswordAuthentication getPasswordAuthentication() {
+					return new PasswordAuthentication(fromEmail, sendingPW);
+				}
+			});
+		}
+		logger.info("Sending mail... " + (files != null ? files.get(0) : ""));
+		try {
+			Message message = new MimeMessage(mailSession);
+			message.setFrom(new InternetAddress(fromEmail));
+			message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail));
+			message.setSubject(subject);
+			List<MimeBodyPart> fileList = new ArrayList<>();
+			if (body != null) {
+				MimeBodyPart aMimeBodyPart = new MimeBodyPart();
+				aMimeBodyPart.setText(body);
+				fileList.add(aMimeBodyPart);
+			}
+			if (files != null) {
+				for (File aFile : files) {
+					MimeBodyPart aMimeBodyPart = new MimeBodyPart();
+					aMimeBodyPart.setDataHandler(new DataHandler(new FileDataSource(aFile)));
+					aMimeBodyPart.setFileName(aFile.getName());
+					fileList.add(aMimeBodyPart);
+				}
+			}
+			message.setContent(new MimeMultipart(fileList.toArray(new MimeBodyPart[0])));
+			Transport.send(message);
+		} catch (MessagingException e) {
+			logger.error("sendGmail:", e);
+			mailSession = null;
+		}
+	}
+}

src/test/java/com/bigboxer23/utils/command/TestRetryingCommand.java

@@ -75,7 +75,8 @@ public void testExecute() throws IOException {
 						throw new IOException("bad");
 					},
 					"test",
-					0, 3);
+					0,
+					3);
 			fail();
 		} catch (IOException e) {
 			assertEquals(4, countHolder[0]);