Spring Boot REST API: PUT vs PATCH Best Practices

Spring Boot Configuration — The Hidden Power Behind Applications In real-world applications, hardcoding values is a big mistake Instead, Spring Boot uses configuration files to manage everything. In simple terms: Spring Boot = “Keep your logic clean, I’ll handle configs separately.” --- 🔹 Where do we configure? application.properties (or) application.yml --- 🔹 What can we configure? ✔ Database connection ✔ Server port ✔ API keys ✔ Environment-based settings (dev / prod) --- 🔹 Example: server.port=8081 spring.datasource.url=jdbc:mysql://localhost:3306/mydb --- Why this is important: ✔ Clean code (no hardcoding) ✔ Easy environment switching ✔ Secure & flexible ✔ Production-ready applications --- Bonus: Using @Value and @ConfigurationProperties, we can inject these configs directly into our code. --- Currently learning and applying these concepts step by step #SpringBoot #Java #BackendDevelopment #Configuration #LearningInPublic #DevOps

Something I still find fascinating about Spring Boot. You write a simple controller like this: @RestController public class UserController { @GetMapping("/users") public List<User> getUsers() { return service.getUsers(); } } Looks simple. But when a request hits this endpoint, a lot happens behind the scenes: • Tomcat accepts the HTTP request • Spring DispatcherServlet receives it • HandlerMapping finds the correct controller • Argument resolvers prepare method parameters • The method executes • Jackson converts the response into JSON All of that… just to return a list of users. Frameworks like Spring Boot hide an incredible amount of complexity so developers can focus on business logic. Sometimes it's worth pausing and appreciating how much engineering is happening behind one simple endpoint. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering

🚀 What actually happens when a request hits a Spring Boot application? Many developers use Spring Boot daily, but understanding the internal flow of a request helps you write cleaner and better backend code. Here is the simplified flow: 1️⃣ Client Request Browser or Postman sends an HTTP request Example: "POST /api/users" 2️⃣ DispatcherServlet Spring’s front controller receives the request and routes it to the correct controller. 3️⃣ Controller Layer "@RestController" receives the request, validates input, and delegates the work to the service layer. 4️⃣ Service Layer "@Service" contains the business logic such as validation, processing, and transformations. 5️⃣ Repository Layer "JpaRepository" interacts with the database and executes SQL queries. 6️⃣ Response to Client Spring converts the Java object to JSON (via Jackson) and sends it back with HTTP 200 OK. --- 🔑 Golden Rules ✅ Controller → HTTP only ✅ Service → Business logic ✅ Repository → Database operations ✅ Each layer has one responsibility (SRP) This layered architecture makes Spring Boot applications clean, testable, and scalable. #Java #SpringBoot #SpringFramework #Backend #SoftwareEngineering #Programming #Developer #Tech #CleanCode #JavaDeveloper

🚀 Day 55/100 - Spring Boot - Logging Once your application is running in production, System.out.println() is not enough ❌ You need structured, configurable, and production-ready logging❗ For that, spring boot uses: 🔹SLF4J (Logging API / facade) 🔹Logback (Default implementation) ➡️ Why Logging Matters? Because it helps you: ✔ Monitor application behavior ✔ Debug issues in production ✔ Track errors ✔ Audit important events ✔ Analyze system health Good logging = easier debugging = better reliability ➡️ SLF4J and Logback 🔹 SLF4J (Simple Logging Facade for Java) 🔹It’s a logging abstraction 🔹Allows switching logging frameworks (Logback, Log4j, etc.) 🔹Spring Boot includes it by default Think of it as an interface for logging. ➡️ Basic Logging Example (see attached image 👇) ➡️ Different Log Levels & their Purpose TRACE: used for very detailed debugging DEBUG: used for development debugging INFO: used for general application events WARN: used for something unexpected ERROR: used for serious problems ➡️ Best Practices ✔ Use INFO for important business events ✔ Use WARN for suspicious behavior ✔ Use ERROR for failures ✔ Avoid excessive logging Previous post: https://lnkd.in/dZVkgwcD #100Days #SpringBoot #Logging #SLF4J #Logback #Java #BackendDevelopment #WebDevelopment #SoftwareEngineering

🔎 What Actually Happens Inside Spring Boot When an API Request Comes In? Most of us write a simple endpoint like: @GetMapping("/users") and the API works. But internally, a lot happens before the response reaches the client. Here’s a simplified internal flow of a request inside a Spring Boot application: 1️⃣ Client Sends HTTP Request The request reaches the embedded server (like Tomcat). 2️⃣ DispatcherServlet Intercepts the Request This is the central component of Spring MVC. Every request first passes through it. 3️⃣ Handler Mapping Identifies the Correct Controller Spring checks which controller method matches the request URL. 4️⃣ Handler Adapter Invokes the Controller Method This component actually executes the method inside the controller. 5️⃣ Business Logic Execution The controller may call services, repositories, or other components to process the request. 6️⃣ Response Processing Spring converts the returned object into JSON using message converters. 7️⃣ HTTP Response Sent Back to Client All of this happens in milliseconds, but understanding this flow helps developers: ✔ Debug request handling issues ✔ Understand how Spring Boot works internally ✔ Design better APIs and interceptors Sometimes the most interesting part of frameworks is not the code we write — but what happens behind the scenes. #Java #SpringBoot #BackendDevelopment #SoftwareArchitecture #SpringFramework

🔄Understanding Internal Request Flow in Spring Boot. I explored how a request travels inside a Spring Boot application 🚀 > Here’s a simplified breakdown of the flow: ➡️ A request starts from the Browser/Postman. ➡️ It reaches the embedded Tomcat Server. ➡️ Then handled by DispatcherServlet (the heart of Spring MVC) ➡️ HandlerMapping identifies the correct controller. ➡️ The request is processed by the Controller. ➡️ HttpMessageConverter transforms data (JSON/XML ↔ Java Objects) ➡️ Finally, the response is sent back through Tomcat to the client. 💡 This architecture ensures scalability, clean separation of concerns, and efficient request handling — which is why Spring Boot is so powerful for building modern backend applications. 📚 As a Java & Backend enthusiast, diving deep into such internal concepts is helping me strengthen my foundation in software engineering. #SpringBoot #Java #BackendDevelopment #SoftwareEngineering

🚀 Spring Boot Annotations Every Backend Developer Must Master Spring Boot may look simple from the outside… But the real magic lies in its annotations 🔥 Building APIs is easy. Designing secure, scalable, production-grade systems? That’s where annotations shine. Here are the ones I use the most in real-world projects: 🔹 Application Bootstrapping @SpringBootApplication @EnableAutoConfiguration @ComponentScan 🔹 Dependency Injection @Autowired @Qualifier @Primary 🔹 REST APIs @RestController @RequestMapping @GetMapping / @PostMapping / @PutMapping / @DeleteMapping 🔹 Database & JPA @Entity @Id @Transactional @Repository 🔹 Validation @NotNull @NotBlank @Size @Email 🔹 Exception Handling @ExceptionHandler @ControllerAdvice @RestControllerAdvice 🔹 Security (Production Level) @EnableWebSecurity @PreAuthorize @Secured Spring Boot isn’t just about writing controllers. It’s about clean architecture, layered design, transaction management, validation, and security. 💬 Which annotation do you use the most in your projects? #Java #SpringBoot #BackendDevelopment #Microservices #SystemDesign #JWT #SoftwareEngineering #LearningInPublic

🚀 Spring Boot Series #003 Spring vs. Spring Boot: Why pick one when you can have both? 🍃👢 The most common interview question for Java devs: "What is the actual difference?" Think of it like this: 🛠️ Spring Framework is the massive toolbox. It gives you every tool imaginable (Dependency Injection, Data Access and many more), but you have to set up the workbench, the lighting, and the instructions. 🚀 Spring Boot is the pre-assembled, turbo-charged factory. It uses the Spring toolbox but handles the setup for you with opinionated defaults. In short: Spring: Total control, but manual configuration (XML/Java Config) and external servers (Tomcat). Spring Boot: Auto-configuration, "Starter" dependencies, and embedded servers. The Verdict: Spring is the engine. Spring Boot is the car that’s already running and ready for a road trip. "We all love Spring Boot's speed, but what’s the biggest 'Auto-Configuration' nightmare you’ve ever had to debug? 🛠️👇" #Spring #SpringBoot #Java #BackendDevelopment #SpringbootwithVC

🚀 Built REST API using Spring Boot framework Today, I worked on creating a REST API using Spring Boot. I implemented: ✅ @RestController for handling HTTP requests ✅ @GetMapping to fetch data ✅ Returned JSON responses ✅ Created a simple User API endpoint Through this, I understood: 🔹 How backend communicates with frontend using JSON 🔹 How HTTP methods (GET, POST, PUT, DELETE) work 🔹 How Spring Boot simplifies API development Example flow: Client → HTTP Request → Controller → Service → Response (JSON) This small step helped me understand how real-world backend systems work. Excited to explore more about REST architecture, exception handling, and database integration next! 💻🔥 #SpringBoot #Java #BackendDevelopment #RESTAPI #LearningJourney 😄

Spring Boot looks simple on the surface. But under the hood, it’s doing a lot. A single request typically flows through: • Controller → handles the request • Service → contains business logic • Repository → talks to the database What this really means is: You get a clean separation of concerns by default. That’s why Spring Boot scales well not just in traffic, but in code maintainability. #Java #SpringBoot #Backend #CleanArchitecture