Spring Boot: Accelerating Java web app and microservices development

What is Spring Boot?

Spring Boot is an open source project with a vibrant community that makes regular contributions to its development. As an extension of the Spring Framework, Spring Boot further simplifies the process of using Spring to build Java applications. Spring Boot adds key features such as pre-configured dependencies, autoconfiguration, monitoring, embedded servers, and starter projects that reduce development time and ease deployment.

The Spring ecosystem

The Spring ecosystem is a collection of open source tools that are designed to help developers build modern, cloud native Java applications easier and faster.

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  Spring Framework. Provides a comprehensive set of features, including dependency injection, aspect-oriented programming, authentication, and more, to make it easier to build large-scale, complex applications.
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  Spring Boot. Accelerates the creation of stand-alone, production-ready applications in Java with pre-configured starter templates and autoconfiguration options, simplifying configuration and enhancing security. It is sometimes referred to as Java Spring Boot.
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  Spring projects. Additional capabilities, referred to as projects, further extend the Spring ecosystem to support the latest techniques and trends. Popular Spring projects include Spring Cloud, Spring Data, Spring Security, and Spring Integration. Developers can leverage these components independently or together to build, scale and operate enterprise-grade applications with less toil and relative ease.

Spring Boot's role within the Spring ecosystem

While the Spring Framework offers flexibility and control over the configuration of large and complex Spring applications, Spring Boot offers simplicity, with autoconfiguration and automation to ease the application development process.

The Spring Framework relies on dependency injection, a design pattern that helps you create loosely coupled, modular applications, where components have clear dependencies. You must either declare dependencies in configuration files or use annotations to tell Spring to create and inject dependencies. Spring Boot, on the other hand, automatically configures applications using classpath scanning to identify the dependencies required by an application, providing an easier, quicker path to set up, configure and run code.

For example, Spring Framework and Spring Boot both provide comprehensive support for authentication. However, in Spring Framework, developers must manually configure authentication-related components, such as AuthenticationManager, PasswordEncoder, and so on, through Java configuration or XML files. This can be a time-consuming process but provides a lot of flexibility to customize the implementation.

Spring Boot provides an opinionated approach to authentication configuration. Spring Boot includes pre-built starter dependencies for various authentication mechanisms, such as OAuth2, JWT, and Basic Authentication. These starter dependencies provide most of the necessary configuration and integration, allowing you to quickly set up and run an authenticated application.

Developing Java apps with Spring Boot

Spring Boot simplifies and accelerates the process of building Java applications using pre-configured settings and dependencies. Here are a few of the key features of Spring Boot:

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  Autoconfiguration. This feature provides default configurations for a large set of common dependencies. When Spring Boot identifies that a dependency is present on the classpath, it automatically configures the corresponding Java beans and settings, removing the need for you to manually configure every aspect of the application. Autoconfiguration is also extensible, allowing you to customize and/or override default configurations and apply your own app-specific configurations.
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  Opinionated. Spring Boot offers a guided framework for web application development, providing a predefined path that proves effective in most scenarios. This opinionated approach accelerates the development of high-quality, scalable applications. It follows the convention over configuration principle, allowing flexibility for overrides if you choose to deviate from the default opinions.
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  Produces standalone applications. Spring Boot enables you to build standalone applications that aren't tied to a specific platform, and that can run locally on a device without requiring an internet connection or other installed services to function. This feature makes Spring Boot especially useful for building microservices that can be deployed and scaled independently.

A helpful Spring Boot tutorial can put you on the path to mastering Spring Boot. You may want to start by “Bootifying” an existing Java application as you migrate to the Spring ecosystem.

Once you have some experience, you may choose to start a project with Spring Initializr, a convenient web-based tool that provides a quick and easy way to create a custom Spring Boot project with your desired configuration and dependencies. Initializr streamlines the project setup process and helps you begin building a customized Spring Boot application with minimal effort.

Spring Boot's core capabilities

Spring Boot makes it faster and easier to begin building applications without the need for extensive configuration and setup. It leverages several key features that enhance project efficiency in addition to autoconfiguration:

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  Starter dependencies. Spring Boot’s pre-built starter dependencies contain commonly used libraries and frameworks, designed to streamline project startup. For example, the Spring Boot starter web dependency includes Tomcat and Spring MVC, allowing developers to easily build web applications.
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  Annotations. Spring Boot uses annotations to simplify the process of configuring and managing an application. Annotations help to reduce the amount of boilerplate code required to configure the application, making it easier to develop and maintain. For example, the @RestController annotation can be used to define a controller that handles incoming HTTP requests.
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  Startup failure. Spring Boot offers robust error reporting for startup failures. This feature includes detailed error messages with a stack trace and suggestions on how to fix problems.
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  Lazy initialization. Spring Boot allows you to defer initialization of beans until they are actually needed. This feature is called lazy initialization and can significantly reduce application startup time.

What is Spring Boot Actuator?

Spring Boot Actuator is a powerful tool for managing and monitoring Spring Boot applications in production. As part of the Spring Boot framework, it provides essential functionality for detecting and troubleshooting issues in your applications, helping you keep your applications healthy over time. It includes a set of pre-built endpoints that add management functionality to your applications in production. Capabilities include:

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  Health checks. The /health endpoint checks the health of your application, returning information about the application’s state, such as whether a database connection is up or not.
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  Metrics. Spring Boot Actuator provides a set of endpoints for monitoring various application metrics, such as the number of HTTP requests, the number of beans in the application context, and much more.
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  Auditing. Another endpoint allows you to access audit information for your application, such as who performed which action and when.
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  Environment management. You view and manage your application's configuration using the /env endpoint. This allows you to inspect and modify environment variables on the fly.
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  Logging management. The /logfile endpoint allows you to view and manage application log files.

What to keep in mind when considering Spring Boot

Here are a few best practices to consider when programming using Spring Boot:

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  Always use the latest stable version of Spring Boot to ensure that you have access to new features, bug fixes, and security patches.
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  Use Spring Boot starters to add functionality to your application and simplify the management of dependencies, properties and configuration.
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  Use Spring Boot's dependency injection and inversion of control capabilities to simplify application architecture and reduce complexity.
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  Follow the principles of RESTful APIs when developing APIs using Spring Boot. This includes using HTTP verbs correctly, creating predictable URLs, and using HTTP status codes appropriately.

These best practices will help you create high-quality, scalable and maintainable applications using Spring Boot. Optimize your application development with Spring Boot by implementing these best practices, ensuring the creation of scalable, maintainable, and high-quality applications.

Tanzu is the place to run Spring

Tanzu is the optimal choice for development, security, migration, and improved performance. Tanzu provides:

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  Simplified development. With Spring’s speed and simplicity, your development teams can build applications more efficiently.
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  Enhanced security. Tanzu Spring Runtime enables your Spring project to be fortified with enterprise-level security. Know your applications are backed by world-class support and access to exclusive features.
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  Seamless migration. Simplifies the migration of existing Spring Cloud-dependent applications, eliminating the stress associated with platform transitions.
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  Improved performance. Spring Boot-native compilation on Tanzu Application Platform and Tanzu Application Service enhances the performance and resource efficiency of your Spring Boot 3.x (or later) applications.

Spring and Tanzu

Tanzu and the Spring team work together to help developers succeed with Spring by:

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  Providing funding and resources to the Spring community
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  Contributing to the Spring codebase
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  Working with the Spring community to promote and adopt Spring technologies
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  Publishing an annual State of Spring report that helps members of the Spring community keep up with the latest trends among their peers. It is also an invaluable resource as the Spring team works with the community to prioritize areas for innovation and identify and resolve issues.

Read the State of Spring 2022 (published March 2023) to understand the latest trends in the adoption of modern architectures and APIs and learn about progress with native compilation, Java concurrency, and how the Spring community is handling software upgrades.

Tanzu offers a number of technologies and services that can further accelerate your efforts with Spring Framework and Spring Boot.

Tanzu Application Platform enables you to jumpstart development efforts, boost velocity, and accelerate the path to production for cloud native applications.

Tanzu Labs can help your teams build the skills they need to succeed with Spring and other modern development methods. Our experts can help you get better results from your Java Spring Boot applications in less time.

Tanzu Spring Runtime provides world class support for your Spring development efforts.

Tanzu Application Service is the best location for hosting Spring and Spring Boot-based applications. It includes Tanzu Spring Runtime and access to additional Spring functionality with add-on services.

Spring Consulting, part of Tanzu Labs, helps teams upgrade to the latest version of Spring, build new applications, or modernize an existing portfolio of apps. Spring Consulting will help establish a culture of continuous upgrading so teams can mitigate risk and keep developers focused on writing new code.

Spring Academy provides the latest information on Spring and certification to ensure developers have the skills needed to support the upgrade work.