Mohamed Aymen Elarbi’s Post

Day 38 Explored some core concepts of the Spring Framework through hands-on practice. 🔹 Bean Configuration – Understanding how Spring manages and creates objects using the IoC container. 🔹 @Component – Learned how Spring automatically detects and registers classes as beans. 🔹 @Autowired – Explored dependency injection and how Spring automatically injects required dependencies. It was interesting to see how these concepts reduce manual object creation and make applications more loosely coupled. Step by step diving deeper into the Spring ecosystem. 🚀 #SpringFramework #Java #BackendDevelopment #DependencyInjection #LearningInPublic

Spring Boot dependency injection (DI) pitfalls I learned building my first REST API: Don't rely on field injection blindly-use constructors for immutability and testability. Scenario: Multiple beans of the same type? @Qualifier saves the day. @Autowired @Qualifier('taskServiceImpl') private TaskService taskService; Pro tip: @Configuration + @Bean for custom wiring. Deployed my task manager CRUD in 20 mins-zero null pointers. Reduced boilerplate by 60%. Try it on your next project! Thoughts? #SpringBoot #Java #BackendDev

Hello Connections 👋 While revisiting some Spring Boot basics recently, I came across something simple but quite useful — how to see all the beans managed by the Spring container. There are actually a couple of easy ways to do this: 👉 1. Using Spring Boot Actuator Just expose the beans endpoint in application.properties: management.endpoints.web.exposure.include=beans Then hit: /actuator/beans You’ll get a detailed view of all beans along with their dependencies. This is really helpful when you want to understand what Spring is creating behind the scenes. 👉 2. Using ApplicationContext programmatically You can also fetch all bean names directly from the container: String[] beanNames = applicationContext.getBeanDefinitionNames(); for (String beanName : beanNames) { System.out.println(beanName); } I found this especially useful while debugging and understanding auto-configuration behavior. If you’ve used any other way to inspect Spring beans, would love to know! #SpringBoot #Java #BackendDevelopment #Learning

✅ What is a Spring Bean? A Spring Bean is an object that is created, managed, and maintained by the Spring IoC Container. In simple terms: Any class whose object is managed by Spring is called a Spring Bean. 🔄 How Spring Bean Works 1️⃣ You define a class 2️⃣ You mark it with an annotation like @Component 3️⃣ Spring creates the object 4️⃣ Spring manages its lifecycle 📌 Example: @Component class Engine { } ✔ Spring creates the Engine object ✔ Spring manages it ✔ This object is called a Spring Bean 🧠 Why Spring Beans are Important No manual object creation (new) Loose coupling Easy dependency injection Better maintainability 💡 Simple Line to Remember Spring Bean = Object managed by Spring Container #Spring #SpringBoot #SpringBean #Java #LearningInPublic #BackendDevelopment

Hi everyone 👋 📌 Spring Boot Annotation Series Part 21 – @PathVariable @PathVariable is used to extract values from the URL path and bind them to method parameters. It is part of the Spring Framework and widely used in REST APIs built with Spring Boot. 🔹 Why Do We Use @PathVariable? In REST APIs, resources are identified using IDs in the URL. Example: GET /users/101 Here, 101 is part of the URL path. @PathVariable helps us capture that value inside the controller method. 🔹 Basic Example @RestController @RequestMapping("/users") public class UserController { @GetMapping("/{id}") public String getUserById(@PathVariable Long id) { return "User ID is: " + id; } } 👉 If request is: GET http://localhost:8080/users/101 Output: User ID is: 101 🔹 In Simple Words @PathVariable takes dynamic values from the URL and passes them to the controller method. #SpringBoot #Java #RESTAPI #PathVariable #BackendDevelopment #InterviewPreparation

Hi everyone 👋 📌 Spring Boot Annotation Series Part 20 – @PatchMapping @PatchMapping is used to handle HTTP PATCH requests for partial updates in REST APIs. It is part of the Spring Framework and widely used in applications built with Spring Boot. 🔹 Why Do We Need PATCH? In REST: PUT → Full update (replace entire object) PATCH → Partial update (update specific fields only) If we only want to update one or two fields, using PUT would require sending the entire object. 👉 PATCH is more efficient. 🔹 What Happens Internally? @PatchMapping is a shortcut for: @RequestMapping(method = RequestMethod.PATCH) 🔹 In Simple Words @PatchMapping updates only the fields that are sent in the request. #SpringBoot #Java #RESTAPI #PatchMapping #BackendDevelopment #InterviewPreparation

Why Spring Is Moving Back Toward Simplicity Reactive programming became popular because: - Threads were expensive - Blocking didn’t scale That led to code like this: Mono<User> user = service.getUser()   .flatMap(this::validate)   .flatMap(this::enrich); Powerful — but hard to: - Read - Debug - Maintain Virtual threads allow this again: User user = service.getUser(); validate(user); enrich(user); Same scalability. Much clearer flow. 💡 Takeaway: Spring and Java are converging toward readability. #Java #SpringBoot #BackendEngineering #Java25

💡 𝐃𝐨 𝐮𝐧𝐮𝐬𝐞𝐝 𝐢𝐦𝐩𝐨𝐫𝐭𝐬 𝐚𝐟𝐟𝐞𝐜𝐭 𝐚 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 𝐚𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧'𝐬 𝐩𝐞𝐫𝐟𝐨𝐫𝐦𝐚𝐧𝐜𝐞? 𝐍𝐨. 𝐁𝐮𝐭 𝐰𝐡𝐲? In 𝐉𝐚𝐯𝐚, import statements are only used by the compiler to resolve class names during 𝐜𝐨𝐦𝐩𝐢𝐥𝐚𝐭𝐢𝐨𝐧. If an 𝐢𝐦𝐩𝐨𝐫𝐭 is not used, the compiler simply ignores it, and it does not appear in the compiled .𝐜𝐥𝐚𝐬𝐬 file. That means unused imports have zero impact on: - Application performance - Memory usage - Spring Boot startup time - Runtime behavior However, they can still affect code readability and cleanliness, so it's a good practice to remove them regularly. 💻 𝐓𝐢𝐩: In 𝐈𝐧𝐭𝐞𝐥𝐥𝐢𝐉 𝐈𝐃𝐄𝐀, you can instantly remove all unused imports in a class using 𝐎𝐩𝐭𝐢𝐦𝐢𝐳𝐞 𝐈𝐦𝐩𝐨𝐫𝐭𝐬. Clean code isn't just about functionality; it's about clarity and maintainability too. #CodingTips #SoftwareEngineering #Java #SpringBoot

Leetcode Problem | | Check If a String Contains All Binary Codes (1461) 🚀 Problem: Given a binary string s and integer k, check if all possible binary codes of length k exist in the string. Example: s = "00110", k = 2 Expected Output = true In substring and sliding window problems, boundary conditions matter more than logic sometimes. Consistent debugging > frustration. #DSA #Java #LeetCode #ProblemSolving #LearningInPublic

Day 37 - Implement Queue using Stacks Implemented a FIFO queue using two stacks while supporting operations like push, pop, peek, and empty. Used one stack for input and another for output. Elements are transferred only when needed to maintain the correct order. Time Complexity: Amortized O(1) #Day37 #LeetCode #Java #Stack #Queue #DSA #ProblemSolving #CodingJourney