Spring Boot- Send email using FreeMarker

By Atul Rai | Last Updated: April 23, 2020 Previous       Next

On this page, we’ll explore how to send an email using Spring Boot and FreeMarker. FreeMarkerTemplateUtils is a utility class for working with FreeMarker template to send the email.

String htmlText= FreeMarkerTemplateUtils.processTemplateIntoString(Template template, Object model);

It returns the processed HTML in the form of a string and throws:

IOException – if a template is not available on the specified path.

TemplateException – parse exception if something specified wrong in the template.

See the code snippet that only different from the how to send email using Spring Boot example.

....

FreeMarkerConfigurer freemarkerConfig;

{
	Template t = freemarkerConfig.getConfiguration().getTemplate("/email/welcome.ftlh");

	String htmlText= FreeMarkerTemplateUtils.processTemplateIntoString(t, dataMap);
}
....

// We can also get a Template object like this...

...

Configuration config;

{
	Template t = config.getTemplate("/email/welcome.ftlh");
	
	String htmlText= FreeMarkerTemplateUtils.processTemplateIntoString(t, dataMap);	
}
...

Note: Spring Boot recently changed the default extension from .ftl to .ftlh

Technology Used

Find the list of all tools/technologies used in this application.

1. Spring Tool Suite 4
2. JDK 8
3. Spring Boot 2.2.6.RELEASE
4. FreeMarker 2.3.30
5. Java Mail 1.6.2
6. Maven 3.2

Dependencies Required

Add the following dependencies to the pom.xml.

<!-- FreeMarker -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>

<!-- Java Mailer -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-mail</artifactId>
</dependency>

Project Structure

The final project structure of our application in STS 4 IDE will look like as follows:

Mail Server Properties

Define the mail server properties in the application.properties file.

# Mail server properties
spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=XXXXXXXXXXX
spring.mail.password=xxxxxxx
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.connectiontimeout=5000
spring.mail.properties.mail.smtp.timeout=5000
spring.mail.properties.mail.smtp.writetimeout=5000
spring.mail.properties.mail.smtp.starttls.enable=true

Email DTO

EmailDTO object is used to pass as an argument for our EmailService to encapsulate the details of an email like recipient email, email subject, etc.

package org.websparrow.dto;

import java.util.Map;

public class EmailDTO {

	private String to;
	private String subject;
	private Map<String, Object> emailData;

	// Generate Getters and Setters...
}

Email Service

A service class that actually pullulate the data to the template and send an email to the recipient address.

package org.websparrow.service;

import java.nio.charset.StandardCharsets;

import javax.mail.internet.MimeMessage;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;
import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;
import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
import org.websparrow.dto.EmailDTO;

@Service
public class EmailService {

	@Autowired
	private JavaMailSender mailSender;
	@Autowired
	private FreeMarkerConfigurer freemarkerConfig;

	public void sendWelcomeEmail(EmailDTO emailDTO) {
		System.out.println("##### Started sending welcome email ####");

		MimeMessage mimeMessage = mailSender.createMimeMessage();
		try {

			MimeMessageHelper helper = new MimeMessageHelper(mimeMessage,
					MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED,
					StandardCharsets.UTF_8.name());

			String templateContent = FreeMarkerTemplateUtils
					.processTemplateIntoString(freemarkerConfig.getConfiguration()
							.getTemplate("/email/welcome.ftlh"),
							emailDTO.getEmailData());

			helper.setTo(emailDTO.getTo());
			helper.setSubject(emailDTO.getSubject());
			helper.setText(templateContent, true);
			mailSender.send(mimeMessage);

			System.out.println("######## Welcome email sent ######");
		} catch (Exception e) {
			System.out.println("Sending welcome email failed, check log...");
			e.printStackTrace();
		}
	}
}

FreeMarker HTML Email Template

Create your beautiful HTML email template and put it under the src/main/resources/templates/email folder. Make sure the file extension of the template must be .ftlh.

<!DOCTYPE html>
<html>
<head>
<title>Welcome Letter</title>
</head>
<body>
	<h3>Dear ${name},</h3>

	<p>A warm welcome and lots of good wishes on becoming part of our growing team.</p>
	<p>We are pleased to inform you that you will work with the following team members:</p>
	<ol>
		<#list teamMembers as teamMember>		
			<li>${teamMember}</li>			
		</#list>		
	</ol>	
	<p>Regards</p>
	<p>Websparrow.org Team</p>
	<p>Location: ${location}</p>
</body>
</html>

Run it

Create an object of EmailDTO and sets the necessary data, call the EmailService to send an email.

package org.websparrow;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.websparrow.dto.EmailDTO;
import org.websparrow.service.EmailService;

@SpringBootApplication
public class SBFreeMarkerEmailApp implements CommandLineRunner {

	@Autowired
	private EmailService emailService;

	@Override
	public void run(String... args) throws Exception {
		System.out.println("###### Email sending initiated ######");

		EmailDTO email = new EmailDTO();

		email.setTo("[email protected]");
		email.setSubject("Welcome Letter via Spring Boot + FreeMarker");

		// Populate the template data
		Map<String, Object> templateData = new HashMap<>();
		templateData.put("name", "Atul Rai");
		// List of team members...
		List<String> teamMembers = Arrays.asList("Tendulkar", "Manish", "Dhirendra");
		templateData.put("teamMembers", teamMembers);
		templateData.put("location", "India");
		email.setEmailData(templateData);

		// Calling email service
		emailService.sendWelcomeEmail(email);
	}

	public static void main(String[] args) {
		SpringApplication.run(SBFreeMarkerEmailApp.class, args);
	}
}

Test it

Start your application by executing the above class and you will receive an email on the provided email address if everything configured correctly.

References

1. Spring Boot + FreeMarker Example
2. How to send email using Spring Boot
3. Example of sending email in Java using Gmail SMTP
4. javax.mail.AuthenticationFailedException