SpringBoot is the most popular and widely used Java framework. Occasionally this discussion of “Why is SpringBoot so popular?” come between me and my friends/colleagues. Also, I do get emails from various people asking “Spring is huge and how to learn it quickly?”. In this post, I will try to answer these 2 questions.

Why is SpringBoot so popular?

There could be many reasons why Spring and SpringBoot are very popular, but in my opinion following are the key reasons:

1. Drastic increase in developer productivity

SpringBoot’s powerful auto-configuration mechanism makes it very easy to get started with a Spring-based application. More importantly, SpringBoot offers a wide array of Starters which is more than sufficient for many applications.

You can create a REST API backed by a database by simply creating a project, selecting Web, Spring Data JPA/Mongo etc, H2/EmbeddedMongo, Spring Data REST starters and create your domain entity and Repository. That’s it, you have a fully functional REST API.

This lowers the entry barrier for newbies and for those who are familiar with how to configure all of these manually and probably done 100’s of times and get tired of writing this boilerplate, SpringBoot is a gift.

2. Simplified Higher level Abstractions

One of the primary goals of Spring and SpringBoot is to make things easier. Spring portfolio has it’s own powerful Web MVC framework, Spring Security framework but the majority of its other projects are to provide higher level abstractions to make using them easier.

For example, Spring Data JPA makes using JPA very easy by providing APIs to perform CRUD operations, Sorting, Pagination without requiring to implement all of them by yourself.

Spring AMQP or Spring for Kafka provides higher-level abstractions so that you can easily work with RabbitMQ or Kafka without writing low-level boilerplate code.

3. Microservices and Cloud Native friendly

Microservice architecture is the latest hot trend now and many organizations prefer microservices architecture and want to deploy them in Cloud environments like AWS, CloudFoundry etc.

Usually, SpringBoot applications are built as self-contained deployment units (FAT Jar) and using its Profiles concept we can deploy the same application in multiple environments without any code changes. In addition to that SpringCloud modules provides a great set of features required for building Cloud Native microservices.

4. Addresses modern business needs

Modern application needs have changed and are continuously changing so rapidly. We can’t wait for 3 to 4 years release cycle to get new features. We need frameworks with rapid release cycles to support these business needs.

Spring at its core is just a Dependency Injection (DI) container. But the power of Spring comes from its rich set of portfolio projects. You want to use NoSQL databases, you want a robust Security framework, you want to integrate with Social platforms, you want to work with Big Data frameworks, you want to use Streaming platforms like Kafka…you are all covered.

5. Spring Developer Community

This is the best part of Spring framework. You can find a million blogs with fantastic blog posts on Spring framework. You can almost find a solution to every problem on StackOverflow. You can reach out to Spring Developer team via Twitter easily.

Challenges with Spring and SpringBoot

When I talk to some people (both juniors and experienced developers) one thing they keep saying is “Spring is huge and complex”. But I have exact opposite opinion on it. After talking to them more about why they feel Spring is complex, I understood why they are feeling like that. It is the same reason why I feel Learning JavaScript frameworks is complex.

Every now and then I get tempted to learn NodeJS and one shiny new JavaScript framework like ReactJS or VueJS etc. First, I try to make a list of things to learn so that I have a benchmark to say I have a decent knowledge of NodeJS/ReactJS etc. After spending 4 to 6 hours and knowing there are 36,794 ways to do anything in JavaScript, I get lost in this ocean of JavaScript tools and options. Then I feel JavaScript is complex.

What I should have done is stop chasing all frameworks/tools and learn barebones JS or ES6 first, and pick one framework, say ReactJS, and one build tool like WebPack and just learn how to use them together properly.

In addition to this feeling of Spring is huge and complex, I also see the following reasons why people say SpringBoot is complex:

1. People directly jump on to SpringBoot without having any prior Spring knowledge and everything looks magical. It works great as long as go with the defaults and the moment you need to customize it, it feels complex.

2. Too many options. When you look for help on some Spring related issue you will always find 100 options to solve it and it is confusing which one to go with.

3. IMHO, Some Spring modules are complex. Sometime back I had to dig deeper into Spring Security source code and I feel it is very complex because it has customization hooks for almost everything.

How to learn Spring and SpringBoot effectively?

I will give you some tips to learn Spring and SpringBoot, basically what I have followed while learning them.

1. Learn Iteratively

I don’t think one can sit and learn everything about a framework in one go. I follow an iterative approach.

Iteration 1: Follow some Quick Start Guide and create a project with all the dependencies set and build a Todo application (Todo is the new HellowWorld right :-)). It gives confidence when you successfully run a sample application.

Iteration 2: Read the official documentation It is very important to understand what problem this particular framework is trying to solve and in what scenarios this framework is suitable and where it is not a good choice. In this regard, Spring framework documentation is awesome and too long too (800+ pages) :-).

Iteration 3: Build a moderately complex application

Iteration 4: Dig deep into framework’s source code and see how you can customize the framework

2. First, learn Spring Core framework

Please don’t jump onto SpringBoot if you don’t have prior knowledge of Spring. I would strongly suggest first to learn Spring framework without SpringBoot so that you know what magic SpringBoot is doing behind the scenes.

Get familiar with Spring DI concepts, Scopes, Annotations, Life Cycle callbacks, bean configuration styles (annotations, @Beans etc). Know how Spring uses Template pattern (JdbcTemplate, JmsTemplate etc) to avoid writing boilerplate code.

3. Learn how SpringBoot AutoConfiguration works

The power of SpringBoot came from its AutoConfiguration mechanism and it is not magic. Learn Spring’s @Conditional feature and explore some SpringBoot’s AutoConfiguration classes like DataSourceAutoConfiguration, JpaAutoConfiguration etc, you can easily understand how SpringBoot is automatically creating beans based on some criteria.

You can read my blog post on How SpringBoot AutoConfiguration magic works? here https://sivalabs.in/how-springboot-autoconfiguration-magic/

4. Follow the community and read blogs

This is the best part of Spring framework, huge community and there are thousands of blogs writing about Spring. One simple way to find these awesome Spring blogs is to follow This Week in Spring series by Josh Long (@starbuxman) posted on Spring Blog every week Tuesday.

5. Practice, practice, and practice

Nothing can replace “practice”. No matter how much you read, how many Spring videos you watch on YouTube..the best way to learn is to use it.

These days I hardly see Java projects not using Spring and SpringBoot. You can learn while working on the project but I strongly suggest to create a Pet project and implement it using various Spring portfolio projects.

After all these, it still takes some time to learn. Take time to master it. Be patient. Reach out to people if you stuck. Read books and blogs. Practice, practice, and practice.

I hope it is helpful and share it if you like it :-)