Refining Backend Skills with Spring Boot

Day 03 Refining my Backend Skills via Projects Today I worked on Global Exception Handling in my Spring Boot Blog API project . What I implemented: • Created a custom ResourceNotFoundException • Added GlobalExceptionHandler using @RestControllerAdvice • Implemented @ExceptionHandler to return clean API error responses • Improved API responses using a custom ApiResponse class • Updated the Custom DTO to Model Mapper This helps make APIs more robust and production-ready by handling errors in a structured way . #Java #SpringBoot #BackendDevelopment #CodingJourney #100DaysOfCode

🚀 Spring Boot Project Workflow Understanding how a backend system works: Client → Controller → Service → Implementation → Repository → Database. Also using Swagger UI for API documentation and testing. Step by step building my Spring Boot Full Stack project. #Java #SpringBoot #BackendDeveloper #SwaggerAPI #SoftwareDevelopment

Day 18 Refining Java Backend via projects Wrapped up API validation today. Tested all endpoints thoroughly Verified role-based access control Validated user APIs via Postman JWT tokens are being generated and working as expected Everything is stable on the backend side now. https://lnkd.in/gGkvPcvz #BackendDevelopment #SpringBoot #JWT #API #Docker #LearningInPublic

🚀 Built my first REST API using Spring Boot This week I implemented a basic REST API as part of my backend development journey. What I built: • CRUD operations (Create, Read, Update, Delete) • API endpoints using Spring Boot • Structured code using Controller, Service, Repository layers Tech used: • Java • Spring Boot • Spring Web Key learning: Understanding how backend systems handle client requests using HTTP methods (GET, POST, PUT, DELETE) was a big step forward. Next step: Connecting this API with a database. #SpringBoot #RESTAPI #Java #BackendDevelopment #Coding

🚀 Understanding Spring Boot Project Structure A well-organized Spring Boot project follows a layered and modular architecture, making applications more scalable, maintainable, and testable. 🔹 Controller Handles HTTP requests and exposes REST APIs. It acts as the entry point of the application. 🔹 Service Contains business logic and core functionalities. It processes data between the controller and repository layers. 🔹 Repository Manages data access using JPA/CRUD operations and communicates directly with the database. 🔹 Model (Entity) Represents database tables as Java classes. Each model maps to a specific table. 🔹 DTO (Data Transfer Object) Used to transfer data between layers, ensuring separation between internal models and external APIs. 🔹 Configuration (Config) Defines application configurations such as beans, CORS, and other setup-related components. 🔹 Security Handles authentication and authorization (e.g., Spring Security, JWT). 🔹 Exception Handling Manages global errors and custom exceptions to ensure clean and consistent API responses. 💡 This layered architecture improves code readability, enforces separation of concerns, and makes your application easier to scale and maintain. #SpringBoot #Java #Backend #SoftwareArchitecture #CleanCode #Programming #Developer

Opening a new Spring Boot codebase and seeing 50 files dumped into a single com.app package instantly triggers my fight-or-flight response. 🏃♂️📁 While structuring the curriculum for the complete Java course I'm building, I realized something important: the hardest thing to teach isn't the syntax, the framework, or the database connections. It's how to not make a mess. When we all start out, we instinctively use Package by Layer. It looks like this: 📁 controllers 📁 services 📁 repositories 📁 entities It looks beautifully clean on Day 1. But by Day 100, when your application has scaled, you have 40 unrelated services crammed into one folder. Making a simple update to the "Order" feature means jumping across four completely disconnected directories. It’s exhausting. Here is the architectural shift that completely changed how I build scalable backends: Package by Feature (or Domain). 📁 order 📄 OrderController.java 📄 OrderService.java 📄 OrderRepository.java 📁 payment 📁 user Why does this make senior engineers and reviewers instantly smile? 🛡️ 1. High Cohesion: Everything related to a specific business feature lives together. When you need to fix a payment bug, your brain only has to focus on the payment folder. 🔒 2. True Encapsulation: In a layered architecture, your OrderService has to be public so the OrderController in another package can see it. In a feature-based architecture, you can use Java's package-private visibility! Only the Controller needs to be exposed to the outside world. 🚀 3. Microservices Ready: If the order domain gets too heavy and needs to be scaled independently, it is already perfectly isolated. Carving it out into its own standalone microservice becomes a thousand times easier. Stop organizing your code like a filing cabinet, and start organizing it like a business. Are you Team Layer or Team Feature? Or have you already ascended to Hexagonal Architecture? Let’s debate in the comments! 👇 Follow RAHUL VIJAYAN for more. #SpringBoot #CleanCode #JavaDeveloper #SoftwareArchitecture #BackendEngineering #CodingLife #SystemDesign

🚀 Exploring REST APIs with Spring Boot Today, I explored how REST APIs work along with the core Spring Boot annotations used to build them. I learned how client-server communication happens using HTTP methods like GET, POST, PUT, and DELETE, and how the server responds with structured data in JSON format. Along with that, I got hands-on understanding of important Spring Boot annotations: 🔹 @RestController → Handles REST requests and returns JSON responses 🔹 @RequestMapping → Maps HTTP requests to specific endpoints 🔹 @GetMapping, @PostMapping, @PutMapping, @DeleteMapping → Simplify API method handling 🔹 @PathVariable & @RequestParam → Used to pass data in APIs 🔹 @RequestBody → Used to receive data from the client 💡 Key Learning: I understood how these annotations reduce boilerplate code and make backend development more efficient and readable. Looking forward to building and implementing REST APIs in my upcoming projects using Spring Boot. #Java #SpringBoot #RESTAPI #BackendDevelopment #LearningJourney #SoftwareDevelopment

⚙️ How a Spring Boot Application Works Internally Many beginners start Spring Boot without understanding its architecture. Here’s the simple structure most projects follow: 📌 Controller → Handles API requests 📌 Service → Business logic 📌 Repository → Database communication 📌 Entity → Database representation 📌 DTO → Data transfer objects 📌 Config → Application configuration 📌 Exception → Global error handling This layered approach helps build clean, scalable, and maintainable applications. Currently exploring Spring Boot and backend development while building real-world projects. 💬 If you're learning Spring Boot, which concept are you focusing on now? #Java #SpringBoot #BackendDeveloper #SoftwareDevelopment #Coding

While learning Spring Boot, one thing I really appreciated is how much it simplifies backend development. Instead of spending time on heavy configuration, you can focus more on building features and designing APIs. A few things that stood out to me: • Auto-configuration reduces setup time • Easy creation of REST APIs • Smooth integration with databases using JPA/Hibernate It’s interesting how frameworks like Spring Boot allow developers to focus more on problem-solving rather than boilerplate code. Still exploring more about the Spring ecosystem and backend architecture. #SpringBoot #JavaDeveloper #BackendDevelopment

Day 9 – Spring Boot Project Structure: How Real Backend Projects Are Organized Today I explored how Spring Boot projects are structured in real-world backend applications. Writing APIs is one thing, but organizing the project properly is what makes an application scalable, maintainable, and production-ready. Here is a simple structure commonly used in real backend projects: controller – Handles HTTP requests and responses service – Contains business logic repository – Communicates with the database using JPA entity – Database table mappings dto – Request and response objects (DTO pattern) exception – Global exception handling config – Configuration classes util – Utility/helper classes This layered architecture helps developers keep code clean, modular, and easy to maintain, especially when working with large applications or microservices. As a backend developer, understanding this structure is very important because most real company projects follow a similar pattern. Every day I’m learning something new and sharing it publicly to improve my understanding. #Java #SpringBoot #SpringFramework #BackendDevelopment #Microservices #LearningInPublic