Spring Boot is an open-source micro framework maintained by a company called Pivotal. It provides Java developers with a platform to get started with an auto configurable production-grade Spring application. With it, developers can get started quickly without losing time on preparing and configuring their Spring application.
This post will guide you through understanding what Spring Boot is and what it’s used for.
But before diving in, we’ll briefly discuss its underlying tool: Spring. Why? Understanding Spring is crucial to formulate a constructive opinion about Spring Boot.
What’s the Difference Between Spring and Spring Boot?
As I said at the start of this post, understanding the differences between both Spring and Spring Boot is crucial for deciding whether to use this framework or not. Therefore, we should make the differences between both clear.
First, let’s talk about how they work together.
Spring Boot is built on top of the Spring framework, and it comes with many dependencies that can be plugged into the Spring application. Some examples are Spring Kafka, Spring LDAP, Spring Web Services, and Spring Security. However, developers have to configure each building brick themselves using a lot of XML configuration files or annotations.
Now, how do they differ?
Well, the Spring framework focuses on providing flexibility through its dependency injection feature. It helps to inject the required dependencies quickly but also to develop your application in a loosely coupled fashion. Some other benefits include:
- A lightweight framework.
- Helps with loose coupling dependencies and testability. The modular architecture allows you to pick the parts you need and isolate them.
- Has support for both XML and annotation configuration.
- Provides abstraction on ORM software to develop the ORM persistence logic.
- Compatible with many middleware services.
- Supports the JDBC framework, which improves productivity and reduces errors.
Spring Boot, on the other hand, is focused on shortening the code length and providing you with an easy way to run your Spring application.
Do You Need to Learn Spring First?
If you’re wondering if you need to learn Spring first, the short answer is no.
The Spring framework has been made significantly more user-friendly with the development of Spring Boot. Unless you have a specific reason for doing so, there is really no reason to use the old framework.
It also makes sense to stick to learning how to configure your libraries using Spring Boot as it is still an integration framework. This is easy to do, but sometimes these libraries require some configuration.
Notable Features of Spring Boot
- Autoconfiguration: Developers can automatically configure their Spring application. However, Spring Boot is also capable of changing the configuration based on the dependencies you list. For example, when you list “MySQL” as a dependency, it will configure your Spring application with the “MySQL connector” included. And if you want to add a custom configuration, you can create a class that overrides the default configuration for your “MySQL connector”.
- Standalone: There’s no need to deploy your application to a web server. You simply enter the run command to start the application.
- Opinionated: On the official page, we find that Spring Boot decides for you which defaults to use for the configuration. Also, it decides which packages to install for the dependencies you require. For example, if you include the Spring Boot starter “pom” for “JPA”, it will autoconfigure an in-memory database, a hibernate entity manager, and a simple data source. This is an example of an opinionated default configuration that you can override. While some developers might feel this is too opinionated, Spring Boot’s opinionated setup helps developers to get started quickly on their projects.
Why Is Spring Boot So Popular?
First of all, it makes use of Java, which is one of the most popular programming languages in the world. Besides that, Spring Boot is an amazing tool that helps you to get enterprise-grade applications up and running quickly without having to worry about configuring your application correctly and safely.
Also, the user community is huge. If you want free learning materials and courses, you’ll find plenty out there. The accessibility of education has had a big impact on the framework’s popularity.
Some additional benefits include:
- Reduces development time and increases the overall productivity of the development team.
- Helps you autoconfigure all components for a production-grade Spring application.
- Makes it easier for developers to create and test Java-based applications by providing a default setup for unit and integration tests.
- Avoids writing lots of boilerplate code, annotations, and XML configuration.
- Comes with embedded HTTP servers like Tomcat or Jetty to test web applications.
- Adds many plugins that developers can use to work with embedded and in-memory databases easily. Spring allows you to easily connect with database and queue services like Oracle, PostgreSQL, MySQL, MongoDB, Redis, Solr, ElasticSearch, Rabbit MQ, ActiveMQ, and many more.
- Allows admin support—meaning you can manage via remote access to the application.
Disadvantages of the Spring Boot Framework
The main struggle for many developers when using Spring Boot is the lack of control you have. The opinionated style installs many extra dependencies it assumes you’ll need. By installing all these extra dependencies (which sometimes go unused), the deployment binary size can become very large.
Next, The Spring Boot artifact can be directly deployed into Docker containers. This is great for quickly creating microservices. However, some developers argue that since the framework has been built to be agile and lightweight, it should therefore not be used for monolithic applications.
Learn more about microservices with Spring Boot here.
Last on the list of disadvantages is this: when you want to upgrade your legacy Spring code, it can be quite a struggle. Spring Boot tries to meet such use cases by providing several different tools, like a CLI tool that helps you with migrating your legacy code.
Monitoring Spring Boot Applications
Although Spring Boot by default comes with some basic tools for monitoring logs and the health of your application, these aren’t sufficient. A tool like Retrace helps teams easily monitor Java applications.
Retrace helps you to detect slow SQL queries, gives you reports about performance and CPU usage, and shows the most commonly occurring errors by interpreting the logs.
In a Nutshell
The main goal of the Spring Boot framework is to reduce overall development time and increase efficiency by having a default setup for unit and integration tests. If you want to get started quickly with your Java application, you can easily accept all defaults and avoid the XML configuration completely. If you want to get started with your first Spring Boot application, you can find a 15-minute tutorial in the official documentation.