Spring Boot – Sending email with attachment code example

Spring Boot provides convenient support for sending email messages using the JavaMailSender interface.

Need to include the spring-boot-starter-mail dependency. This starter module simplifies the configuration and usage of email functionality in Spring Boot application.

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

Configure email properties:

emailconfig.recipients=<To_EMAIL_ID>
emailconfig.sender=<FROM_EMAIL_ID>
emailconfig.body=<EMAIL_BODY>
emailconfig.subject=<EMAIL_SUBJECT>
spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=<MAIL_USERNAME>
spring.mail.password=<MAIL_PASSWORD>
spring.mail.properties.mail.smtp.starttls.required=true

Create model to load the email configurations. The @ConfigurationProperties annotation is used to bind external configuration properties to a Java class. This annotation allows to map properties defined in configuration files (e.g., application.properties or application.yml) to fields in a POJO (Plain Old Java Object) class. It’s a convenient way to centralize and manage configuration properties in Spring Boot application.

package com.example.SpringEmailDemo.model;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Configuration
@ConfigurationProperties("emailconfig")
public class EmailConfig {
	
	private String recipients;
	private String sender;
	private String body;
	private String subject;

}

Create a service that will handle sending emails which uses JavaMailSender interface for this purpose.

package com.example.SpringEmailDemo.service.impl;

import java.io.File;

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

import com.example.SpringEmailDemo.model.EmailConfig;
import com.example.SpringEmailDemo.service.EmailService;

import jakarta.mail.internet.MimeMessage;

@Service
public class EmailServiceImpl implements EmailService{
	
	@Autowired
	private JavaMailSender javaMailSender;


	public void sendEmail(EmailConfig emailConfig) {
		MimeMessage mineMessage = javaMailSender.createMimeMessage();
		
		MimeMessageHelper mimeMessageHelper;
		
		try {
			mimeMessageHelper = new MimeMessageHelper(mineMessage,true);
			mimeMessageHelper.setFrom(emailConfig.getSender());
			mimeMessageHelper.setTo(emailConfig.getRecipients());
			mimeMessageHelper.setText(emailConfig.getBody());
			mimeMessageHelper.setSubject(emailConfig.getSubject());
			
			String fileName="D://1.txt";
			
			FileSystemResource file = new FileSystemResource(new File(fileName));
			Path path = Paths.get(fileName);
			byte[] contents = Files.readAllBytes(path);
			mimeMessageHelper.addAttachment(file.getFilename(), new ByteArrayResource(contents));
			
			javaMailSender.send(mineMessage);
			
		}
		catch(Exception ex) {
			ex.printStackTrace();
		}
	}

}

Controller to define API to send email.

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.SpringEmailDemo.model.EmailConfig;
import com.example.SpringEmailDemo.service.EmailService;

@RestController
public class SpringEmailDemoController {

	@Autowired
	EmailConfig emailConfig;
	
	@Autowired
	EmailService emailService;
	
	@PostMapping("/sendEmail")
	public void sendEmail() {
		
		emailService.sendEmail(emailConfig);
	}
}

For complete source code: https://github.com/MMahendravarman/Springboot_Examples