Learn Spring Boot 3 in 100 Steps - No 1 Java Framework

It looks like you've outlined a comprehensive guide for building a Spring Boot application with RESTful services, integrating JPA data persistence, adding user authentication with Spring Security, and ensuring robust testing practices. Your guide is well-structured and covers a wide range of topics that are essential for developing a full-featured web application using the Spring Boot framework.

Here's a brief summary of what each step entails:

1. Setting up the Spring Boot Project: You start by creating a new Spring Boot project, configuring it with Maven or Gradle, and setting up your development environment.

2. Adding Dependencies: You add necessary dependencies like Spring Web, Thymeleaf, Bootstrap CSS via webjars, JPA, and Spring Security.

3. Creating the Todo Service: You implement the business logic for creating, reading, updating, and deleting todo items.

4. Adding Validations: You use Spring Boot's validation framework to ensure data integrity.

5. Implementing CRUD Operations: You create the necessary REST endpoints to perform Create, Read, Update, and Delete operations on todo items.

6. Integrating with a Database: You set up H2 in-memory database for development and later connect to MySQL or another production-ready database using JPA.

7. Configuring Spring Security: You secure your application with user authentication and authorization, customizing as needed.

8. Testing: You write both integration tests and unit tests to ensure your application behaves as expected, with no side effects in the latter.

9. Connecting to MySQL Database (Optional): If you decide, you can connect your Spring Boot application to a MySQL database instead of H2.

10. Docker Integration (Optional): You learn how to containerize your application using Docker.

For the REST API part, you start with creating a simple "Hello World" service and gradually move on to more complex operations like handling survey questionnaires, user management, and securing these endpoints with Spring Security.

Each step is designed to build upon the previous one, ensuring that you have a solid foundation before moving on to more advanced topics. This approach helps in understanding how different parts of the application interact and depend on each other, which is crucial for creating robust, maintainable codebases.

Your guide also emphasizes the importance of following best practices, such as RESTful design principles, testing methodologies, and security conventions. By the end of this journey, you should have a fully functional Spring Boot application with a rich set of features, ready for real-world use or deployment.