SKN Reactive Spring Boot Mail Library

Java

 

JavaDocs:

Read the Javadoc for the main Service APIs

• MailSenderService API
• MailSenderRequestInfo API
• MailSenderInputStream API
• MailSenderHtmlTemplate API

 

Introduction:

This is a simple Java Reactive Spring Boot Library for sending mails

I made this library so that I can use it in most of my spring boot reactive projects without writing the same codes over and over again

The main API Classes of this library are MailSenderService which has 4 methods to send mails, MailSenderRequestInfo which holds the blueprint for @RequestBody/@RequestPart annotated params, MailSenderInputStream which holds the blueprint for processing proper input stream info & MailSenderHtmlTemplate which holds the blueprint for processing proper thymeleaf HTML template info. These APIs are for controllers

 

Details:

(1) MailSenderService Class:

• It needs to be instantiated first
• It must be used in controller POST requests
• It has 4 methods to send mails
• These 4 methods throw MessagingException if sending error occurs
• 2 methods out of 4 also throw IOException if file attachment error occurs
• The modes to send mails:
  • Basic Mail (It throws MessagingException)
  • Basic Mail With Attachment (It throws MessagingException & IOException)
  • Mail With HTML Template (It throws MessagingException)
  • Mail With HTML Template & Attachment (It throws MessagingException & IOException)

(2) MailSenderRequestInfo Class:

• It is the blueprint for @RequestBody/@RequestPart annotated params in controllers
• In controller POST requests, the request body or request part must match the blueprint of it

(3) MailSenderInputStream Class:

• It is the blueprint for processing proper input stream info in controllers
• In controller POST requests, it will receive MultipartFile type as @RequestPart
• Then this API instance should be created with the input stream

(4) MailSenderHtmlTemplate Class:

• It is the blueprint for processing proper thymeleaf HTML template info in controllers
• The project should have a Thymeleaf Html Template already
• Then this API instance should be created with the template name and the variable name inside that template

 

Requirements:

• 💀 Minimum Java Version: 21
• 💀 Minimum Spring Boot Version: 3.3.5
• 💀 Spring Web Flux (Reactive Spring Boot)
• 💀 Spring Java Mail Sender
• 💀 Spring Thymeleaf

 

Usage:

For Maven, inside dependencies tag of pom.xml, copy the following

<dependency>
  <groupId>best.skn</groupId>
  <artifactId>skn-spring-mail</artifactId>
  <version>2.4.0</version>
</dependency>

For Gradle, inside dependencies block of build.gradle.kts, copy the following

implementation("best.skn:skn-spring-mail:2.4.0")

First create a configuration class

import best.skn.mail.configurations.MailSenderConfiguration;

@Configuration
@Import(MailSenderConfiguration.class)
public class MailSenderSpringConfiguration {}

Inside your Java Code, import the package like this for MailSenderService

import best.skn.mail.services.MailSenderService;

Inside your Java Code, import the package like this for MailSenderRequestInfo, MailSenderInputStream & MailSenderHtmlTemplate

import best.skn.mail.models.*;

In controller POST requests, use it like the following (Just an example)

@Autowired
private MailSenderService mailSender;

@PostMapping("/endpoint-for-basic-mail")
public Mono<String> sendMail(@RequestBody MailSenderRequestInfo info)
throws MessagingException {
  return this.mailSender.sendMail(info);
}

@PostMapping("/endpoint-for-mail-with-attachment")
public Mono<String> sendMailWithAttachment(
  @RequestPart MailSenderRequestInfo info,
  @RequestPart MultipartFile file
) throws MessagingException, IOException {
  MailSenderInputStream stream = new MailSenderInputStream(
    "output file location here",
    file.getInputStream()
  );

  return this.mailSender.sendMailWithAttachment(info, stream);
}

@PostMapping("/endpoint-for-mail-with-html-template")
public Mono<String> sendMailWithHtmlTemplate(
  @RequestBody MailSenderRequestInfo info
) throws MessagingException {
  // you must have "mail.html" in `resources/templates` and the template must have a `message` variable
  MailSenderHtmlTemplate template = new MailSenderHtmlTemplate(
    "mail.html",
    "message"
  );

  return this.mailSender.sendMailWithHtmlTemplate(info, template);
}

@PostMapping("/endpoint-for-mail-with-html-template-and-attachment")
public Mono<String> sendMailWithHtmlTemplateAndAttachment(
  @RequestPart MailSenderRequestInfo info,
  @RequestPart MultipartFile file
) throws MessagingException, IOException {
  // you must have "mail.html" in `resources/templates` and the template must have a `message` variable
  MailSenderHtmlTemplate template = new MailSenderHtmlTemplate(
    "mail.html",
    "message"
  );

  MailSenderInputStream stream = new MailSenderInputStream(
    "output file location here",
    file.getInputStream()
  );

  return this.mailSender.sendMailWithHtmlTemplateAndAttachment(info, template, stream);
}

When requesting the API from Postman or Frontend Framework for mails without attachment, the request body json format can be like the following-

{
  "from": "sender email address",
  "to": "receiver email address",
  "subject": "mail subject",
  "body": "mail body"
}

When requesting the API from Postman or Frontend Framework for mails with attachment, the request should be made with form-data format as it will be processed with @RequestPart

 

Dedicated To:

• 👩‍🎨Prodipta Das Logno & 🧛‍♀️Atoshi Sarker Prithula: The two most special ladies of my life. My best wishes will always be with you two. May you two always be happy.
• 💯My Parents: The greatest treasures of my life ever.

 

License:

Copyright (C) 2024 SKN Shukhan

Licensed under the Apache License, Version 2.0