Apache Tomcat vs Spring Boot: What are the differences?

Apache Tomcat and Spring Boot are both popular frameworks used for developing Java-based web applications. Let's explore the key differences between them.

1. Deployment Properties: Apache Tomcat is a servlet container that requires a separate web server, such as Apache HTTP Server, to handle HTTP requests. On the other hand, Spring Boot is an embeddable web server that can run standalone without external dependencies. This means that Spring Boot provides an all-in-one solution for deploying web applications, whereas Apache Tomcat requires additional configuration for deployment.

2. Configuration: Apache Tomcat requires a separate XML configuration file (server.xml) for specifying various settings related to server, connectors, and resources. Spring Boot, however, uses a convention-over-configuration approach, where most of the settings are automatically inferred based on project dependencies and configuration files like application.properties or application.yml. This makes it easier and quicker to configure a Spring Boot application compared to Apache Tomcat.

3. Dependency Management: Apache Tomcat is primarily a servlet container and does not provide built-in support for dependency management. Developers need to manually manage dependencies by including them in the web application's lib directory. Spring Boot, on the other hand, comes with built-in dependency management using Maven or Gradle. It provides a powerful dependency injection mechanism and easily resolves and includes dependencies, making it more convenient for developers to manage project dependencies.

4. Convention over Configuration: Spring Boot follows a "convention over configuration" paradigm, where defaults and conventions are used to minimize configuration. It automatically configures many aspects of the application, such as database connection, logging, and transaction management, based on established conventions and sensible defaults. Apache Tomcat, on the other hand, requires explicit configuration for each aspect of the application.

5. Ecosystem: Apache Tomcat has been around for a long time and has a mature ecosystem with a large community of users and contributors. It has extensive documentation and a wide range of resources available. Spring Boot, being a relatively newer framework, has a rapidly growing ecosystem with strong community support. It benefits from the extensive Spring ecosystem, including support for various Spring projects such as Spring Data, Spring Security, and Spring Integration, which makes it easier to integrate with other technologies and frameworks.

6. Component Framework: Apache Tomcat is primarily a servlet container and focuses on the execution of Java servlets and JavaServer Pages (JSP). However, Spring Boot is built on top of the Spring framework, which provides a comprehensive suite of features and modules for building enterprise-level applications. Spring Boot includes many additional features such as dependency injection, AOP (Aspect-Oriented Programming), MVC (Model-View-Controller) framework, and support for various architectural patterns like REST, Microservices, and Messaging.

In summary, while Apache Tomcat is a servlet container that requires a separate web server, Spring Boot is an embeddable web server that provides an all-in-one solution for deployment. Spring Boot also simplifies configuration, dependency management, and leverages the extensive Spring ecosystem.