In the corporate world, they say “Java is immortal!”. But Why? Java remains one of the major platforms for developing enterprise applications. Enterprise Applications are used by large companies to make money. Those applications have high-reliability requirements and an enormous codebase. According to a Java Developer Productivity Report, 62% of surveyed developers are using Spring Boot as their main framework technology.
Now the questions that arise are, What’s Spring Boot? Why it’s so much popular nowadays? What’s the best way to master Spring Boot? How to start? Where to start? What topics one should cover? etc, etc. Do you need to learn all the concepts from a book or you should go with some online tutorials or you should learn Spring Boot by doing some projects on it? So in this article, we are going to discuss all these things in detail.
Why Spring Boot if There is Already Spring!
Spring is widely used for creating scalable applications. In the case of web applications, Spring provides Spring MVC which is widely used to create scalable web applications. But the major drawback of spring projects is that configuration is really time-taking and can be a bit tedious for the new developers. To make the application production-ready takes some time in spring. And the solution for this is Spring Boot.
Spring Boot is created on the top of the spring and includes all the features of spring. And is becoming a favorite of developers these days because of its rapid production-ready environment which allows the developers to directly concentrate on the logic instead of struggling with the configuration and setup.
Please refer to this article for a detailed explanation: Difference between Spring and Spring Boot
What’s Spring Boot?
Spring Boot is one of the most popular and used frameworks of Java Programming Language. It is a framework based on microservice and making a production-ready application using Spring Boot takes very little time. It is very easy to create stand-alone, production-grade Spring-based Applications that you can “just run“. So some of the main features of Spring boot are listed below.
- Create stand-alone Spring applications
- Embed Tomcat, Jetty, or Undertow directly.
- Provide ‘starter’ dependencies to simplify the build configuration.
- Automatically configures Spring and 3rd party libraries whenever possible.
- Provide production-ready features like health checks, and externalized configuration.
- No code generation and no requirement for XML configuration.
Spring Boot simplifies Spring development by:
- Auto-configuration: Spring Boot automatically configures many common beans based on the libraries you include in your project. This eliminates the need for a lot of manual configuration.
- Rapid application development (RAD): Spring Boot provides a quick and easy way to get started with Spring projects. You can create a Spring Boot application with minimal configuration and have it running in minutes.
- Production-ready features: Spring Boot includes features like health checks and externalized configuration that are essential for production applications.
Why Spring Boot? (Decide the Goal First)
So before jumping into the complete Roadmap of Spring Boot one should have a clear goal in his/her mind that why he/she wants to learn Spring Boot? Is it for your college academic projects? Or Is it for your long-term career? Or Do you want to build your websites to start your business? So first make a clear goal. Why do you want to learn Spring Boot?
Best Way to Master Spring Boot – A Roadmap to Learn
Start with the Overview of Spring Boot. Read some Spring Boot-related blogs and also research some \ Spring Boot-related things. For example, read blogs on Introduction to Spring Boot, Why Spring Boot? if there is already Spring, etc., etc. and make a complete mind makeup to start your journey on Spring Boot. Make yourself self-motivated to learn Spring Boot and build some awesome projects using Spring Boot. Do it regularly and also start learning one by one new concept on Spring Boot. It will be very better to join some workshops or conferences on Spring Boot before you start your journey. Make your goal clear and move on towards your goal.
1. Learn Java Programming
Spring Boot is a Java framework, so having a solid understanding of Java is essential. This includes concepts like object-oriented programming, variables, data types, control flow statements, and collections.
2. Spring Framework
To master Spring Boot you need to learn the Spring framework first. So we will suggest, you must know the basics of the Spring framework at least. Without learning the core spring framework you are not going to get the “Ahh!!” moment about Spring Boot such as what are the things it carries to the table. In the spring framework, you need to learn these things
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Core:
- Bean Life Cycle: Understand how Spring creates, manages, and destroys beans.
- Dependency Injection: Learn how to inject dependencies between beans for loose coupling.
- Inversion of Control (IoC): Grasp how Spring manages object lifecycles instead of relying on traditional new/delete keywords.
- Bean Factory and Application Context: Explore how Spring creates and manages beans in an application.
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Web:
- Annotations: Learn annotations like @Controller, @RequestMapping, and @ResponseBody for building web applications.
- MVC Structure: Understand the Model-View-Controller (MVC) design pattern for separating concerns in web applications.
- Configuration: Explore configuration options using Java annotations or XML for defining beans and application settings.
- Integrating Libraries/Frameworks: Learn how to integrate Spring with other libraries like Hibernate for database access.
- Profiles: Discover how to manage different application configurations (e.g., development, test, production) using profiles.
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AOP (Aspect Oriented Programming):
- How AOP Works: Explore how AOP allows for adding functionality (aspects) to existing code without modifying it directly.
- Creating Pointcut, JoinPoint, Aspect (Basics Only): Learn the basic concepts of these AOP elements for modularizing cross-cutting concerns.
3. Spring Security
Spring Security is a powerful framework for securing your Spring applications. It provides features for authentication (verifying user identity), authorization (determining user permissions), and access control (restricting access to resources based on permissions). While not mandatory for basic Spring Boot projects, learning Spring Security is valuable for most real-world applications that require user management and data protection. Here are some key concepts to understand:
- Authentication Mechanisms: Understand different authentication mechanisms supported by Spring Security, such as form-based login (username and password), OAuth2 (social logins like Google or Facebook), and JWT (JSON Web Token) for token-based authentication.
- Authorization with Roles: Learn how to define user roles and assign permissions to those roles. Spring Security allows you to control access to application resources based on a user’s roles.
4. Spring Boot
Once you have an understanding of spring firework and how to implement spring security that is the time you need to switch to spring boot. And at that time you are going to get the “Ahh!!” moment about Spring Boot because whatever you did and whatever the configuration you are doing for the spring application that everything will be automated in the spring boot. So let’s see what you need to learn in spring boot
4.1: Importance of Spring Boot
- Rapid Application Development (RAD): Spring Boot excels at creating Spring applications quickly and efficiently. It provides pre-configured defaults and simplifies common tasks, reducing development time significantly.
- Microservices Architecture: Spring Boot is a popular choice for building microservices architectures. Microservices are small, independent services that work together to form a larger application. Spring Boot’s features like auto-configuration and embedded servers make it well-suited for developing microservices.
4.2: Auto Configuration and Custom Configuration
Spring Boot comes with auto-configuration. Whatever the configuration you accomplish while creating the spring application using the spring web and spring AOP you have to do add a lot of configurations. These all configurations are been automated, auto-configured in the spring boot. So by default configuration would be always there, but whenever you want to modify these configurations you can modify all those configurations. So you should learn all these things like how to modify a particular configuration which is been autoconfigured. So that is a really important part of the spring boot because it is always not advisable to use the default configuration though these configurations are created with certain parameters kept in mind.
4.3: Properties and YAML Configuration
Managing Configuration: Explore how to create properties files (.properties) or YAML files (.yml) to manage application configuration settings. These files store key-value pairs for various configuration options. Spring Boot reads these files and uses them to configure the application. YAML is a more readable and concise format compared to properties files.
4.4: Integration with External Libraries/Frameworks
Seamless Integration: Learn how to integrate Spring Boot with various libraries and frameworks to extend its functionality. This could involve connecting to databases using JPA or JDBC, integrating with messaging systems like Kafka or RabbitMQ, or using caching providers like Redis or Memcached. Spring Boot provides mechanisms for smooth integration with a wide range of technologies.
4.5: REST API
Ideally, spring boot is used to create the REST APIs to be consumed or to be consumed by the other application and to use in the microservices. You just learn the following things in REST API
- REST API Design Principles: Understand the core concepts of RESTful APIs, including proper resource identification, use of HTTP methods (GET, POST, PUT, DELETE), and returning appropriate HTTP status codes.
- Spring MVC for REST APIs: Leverage Spring MVC features like @RestController and @RequestMapping annotations to build RESTful APIs in your Spring Boot application. These annotations simplify the process of defining controllers and handling incoming API requests.
5. Databases
Spring Boot applications often interact with databases to store and manage data. Here’s an overview of database technologies you might encounter:
5.1 SQL Databases
- SQL (Structured Query Language): A standardized language for interacting with relational databases. It allows you to perform operations like data retrieval, insertion, updation, and deletion using queries.
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Popular Relational Databases:
- MySQL: MySQL is a free and open-source relational database management system known for its ease of use and scalability.
- PostgreSQL: PostgreSQL is Another popular open-source relational database offering advanced features like ACID transactions and complex data types.
- Oracle: A commercial relational database management system known for its high performance, reliability, and robust security features.
5.2 NoSQL Databases
- NoSQL (Not Only SQL): A category of databases that don’t follow the relational model. NoSQL databases offer flexibility for different data structures and can be a good choice for specific use cases like handling large amounts of unstructured data or high-availability requirements.
- Common NoSQL Databases:
5.3 Spring Data for Simplified Data Access
Spring Data simplifies database access in Spring applications. It provides implementations for various database technologies, allowing you to interact with databases using a consistent API regardless of the underlying database type. Here are some Spring Data modules you might use:
- Spring Data JPA: Provides a layer on top of JPA (Java Persistence API) for object-relational mapping. JPA allows you to work with database entities as Java objects, simplifying data access logic.
- Spring Data MongoDB: Offers a convenient way to interact with MongoDB databases using a familiar Java object-oriented approach.
- Spring Data JDBC: Allows you to interact with relational databases using traditional JDBC APIs. Spring Data JDBC provides a higher-level abstraction over raw JDBC, reducing boilerplate code and improving exception handling.
We will suggest starting with the SQL Database so from that database you will get a core knowledge of how a database works and how are the different operations performed in the database.
6. Microservices
Microservices are small, loosely coupled distributed services. Microservice Architectures evolved as a solution to the scalability and innovation challenges with Monolith architectures (Monolith applications are typically huge – more than 100,000 lines of code). It permits to take a large application and break it into easily manageable small components with slightly defined responsibilities. This approach offers several benefits:
- Scalability: Individual microservices can be scaled independently to meet varying demands. If one service experiences a surge in traffic, it can be scaled up without affecting other services.
- Maintainability: Smaller, focused services are easier to develop, test, and maintain. Developers can work on individual services without needing to understand the entire application complexity.
- Resilience: If one microservice fails, it doesn’t necessarily bring down the entire application. Other microservices can continue functioning, promoting fault tolerance and improved system uptime.
Read more in this article: Microservices Introduction.
Here are some key Spring Cloud components for building microservices with Spring Boot:
- Spring Cloud Gateway: Acts as an API Gateway, serving as a single entry point for incoming API requests. It routes these requests to appropriate microservices based on defined rules.
- Spring Cloud Config: Provides a centralized configuration management system for microservices. This allows you to manage configuration settings for all your microservices from a single location, simplifying configuration management.
- Spring Cloud Circuit Breaker: Implements circuit breaker patterns to handle failures in microservices. A circuit breaker can automatically fail fast and prevent cascading failures if a microservice becomes unavailable.
- Spring Cloud OpenFeign: Simplifies interactions between microservices using a declarative HTTP client. OpenFeign allows you to define interfaces for interacting with other microservices and hides the underlying HTTP communication details.
- Spring Cloud Sleuth: Enables distributed tracing, allowing you to track requests across multiple microservices. Distributed tracing helps you identify performance bottlenecks and debug issues that span multiple services.
There are many other Spring Cloud projects that can be used depending on your specific needs. These include service discovery (e.g., Spring Cloud Eureka), message queuing (e.g., Spring Cloud Stream), and configuration bus (e.g., Spring Cloud Bus).
It’s also beneficial to have a basic understanding of microservices design patterns like:
- Aggregator: A pattern where one service aggregates data from multiple microservices to provide a unified view.
- CQRS (Command Query Responsibility Segregation): A pattern that separates read (queries) and write (commands) operations into different services, improving performance and scalability.
- SAGA (SAGA Pattern): A pattern for managing long-running transactions that involve multiple microservices. It ensures consistency across all involved services even if failures occur.
- Event Sourcing: A pattern where application state is stored as a sequence of events. This allows for easier auditing and replay of events for debugging or rebuilding historical data.
7. DevOps for Streamlined Deployments (Optional but Highly Recommended)
DevOps is a culture and set of practices that aim to improve collaboration between development and operations teams. While not strictly necessary for basic Spring Boot development, understanding DevOps principles can streamline deployment, testing, and monitoring of your applications. Here are some key DevOps tools that can be integrated with Spring Boot:
- Docker: Docker provides a way to containerize your Spring Boot applications. Containers package your application with all its dependencies into a self-contained unit, making them more portable and easier to deploy across different environments.
- Kubernetes: An open-source system for automating deployment, scaling, and management of containerized applications. Kubernetes allows you to orchestrate the deployment of your microservices across a cluster of machines.
- Cloud Platforms: Major cloud providers like AWS, GCP (Google Cloud Platform), and Azure offer various services for deploying and managing Spring Boot applications. These services can provide automated build pipelines, container registries, and serverless deployment options.
By following this roadmap and exploring the resources mentioned, you’ll be well on your way to mastering Spring Boot development and building robust, scalable enterprise applications!
Conclusion
Congratulations! You’ve reached the end of this comprehensive guide to Spring Boot development. By now, you’re equipped with a solid foundation for building modern, scalable Java applications using Spring Boot’s powerful features. Remember, this is just the beginning of your Spring Boot adventure. The vast ecosystem of Spring Boot libraries and frameworks offers endless possibilities for exploration. By following this roadmap and continuously learning, you’ll be well on your way to becoming a Spring Boot expert, crafting robust and efficient Java applications that meet the demands of the modern world. Happy coding!