Spring Boot Validation Made Easy with @NotNull and @Valid

⚙️ One Spring Boot Practice That Changed My Code Quality I stopped using field injection. ❌ @Autowired on fields ✅ Constructor Injection Why? ✔ Better testability ✔ Immutable dependencies ✔ Cleaner design Small change… big impact. If you’re still using field injection — try this once. What’s your preferred approach? 🤔 #SpringBoot #Java #BestPractices

Most people use Spring Boot. But very few understand what actually happens when the application starts While going deeper into it, a few things started making more sense How the application context is created What SpringBootApplication really triggers How the bean lifecycle actually works Why proxies are used for things like Transactional And how self invocation can silently break things It is easy to write Spring code Understanding what happens inside is different Still learning and connecting the dots What part of Spring feels confusing to you #Java #SpringBoot #BackendDevelopment #SoftwareEngineering #JavaDeveloper #SystemDesign #Placements

Day 95/200 – LeetCode Challenge. Problem: Remove Duplicates from Sorted List II (Java) Today’s focus was eliminating all duplicate values from a sorted linked list while keeping only distinct nodes. Implemented an efficient two-pointer approach with a dummy node to handle edge cases cleanly. Linked lists require careful pointer management. Dummy nodes simplify boundary conditions. One-pass solution ensures optimal performance. Continuing the 200-day journey, one problem at a time. #LeetCode #Java #CodingChallenge #200DaysOfCode #ProblemSolving

Monday insight: Spring Boot 4.1.0-M3 advances testing annotations and observability, like smarter auto-config in backend pipelines for faster feedback loops. Milestone: https://lnkd.in/g5D8_9mS From framework familiarity, these ease monitoring and testing. Following the 4.1 milestones? What excites you? #SpringBoot #Java #Testing #Observability #TechMilestones

🚨 Spring Boot Trap @Transactional looks simple. But it has rules. It works when: • Called from another bean • Public methods • Proxy is active It fails silently when: • Self-invocation • Wrong propagation • Async methods Result? Data inconsistency. Always test transaction boundaries. Don’t assume they work. #SpringBoot #Java #Transactions #Backend #BackendDevelopment #JavaDeveloper #SoftwareEngineering #TechTips #SoftwareEngineer

🚀 HavocFlow v01.01.00 & v01.02.00 are live on Maven Central! Annotation-driven chaos engineering for Spring Boot — two releases, a lot shipped: ✅ Full test suite · Spring Boot 3.x support · @InjectChaos on interfaces 🛑 @SuppressChaos · 🧬 Scenario inheritance · ⏰ Cron scheduling · 📋 Audit log 🔒 ReDoS fix · ThreadLocalRandom · Pinned Action SHA · Production safety guard Java 8–21 · Spring Boot 2.7+ & 3.x <dependency> <groupId>io.github.havocflow</groupId> <artifactId>chaos-spring-boot-starter</artifactId> <version>01.02.00</version> </dependency> 🔗 https://lnkd.in/gMFMdvRs #SpringBoot #ChaosEngineering #Java #OpenSource

🚀 Learning Exception Handling in Spring Boot Today I worked on handling exceptions in a Spring Boot application to make APIs more robust and user-friendly. What I learned: • Why exception handling is important in backend systems • Using @ExceptionHandler for handling specific exceptions • Implementing @ControllerAdvice for global exception handling • Returning meaningful error responses instead of generic server errors 💡 Key takeaway: Proper exception handling improves API reliability and provides clear feedback to clients instead of exposing internal errors. 🎯 Next step: Integrating exception handling into my existing REST APIs. Small improvements like this make a big difference in real-world applications. #SpringBoot #Java #BackendDevelopment #ExceptionHandling #Coding

Spent 15 minutes wondering why my REST API was returning empty response The endpoint was working fine yesterday Checked the controller and service layer Everything looked correct Turns out I forgot @ResponseBody on the controller method @GetMapping("/users") public List<User> getUsers() {   return userService.getAllUsers(); } Without @ResponseBody Spring tries to resolve a view instead of returning JSON Quick fix was adding @RestController instead of @Controller #Java #SpringBoot #REST #BackendDevelopment

Spring Boot Bean Lifecycle — Most developers ignore this 🔥 Do you know what happens before your bean is ready? Here’s the flow 👇 1️⃣ Bean Instantiation 2️⃣ Dependency Injection 3️⃣ @PostConstruct runs 4️⃣ Bean is ready to use ✅ And before shutdown: 👉 @PreDestroy is called 💡 Why it matters: ✔ Resource initialization ✔ Cleanup logic ✔ Better control over application lifecycle ⚠️ Mistake: Putting heavy logic inside constructors ❌ 👉 Use @PostConstruct instead Understanding lifecycle = writing smarter Spring Boot apps 🚀 #SpringBoot #Java #BackendDeveloper

🚀 Mastering Spring Boot – Step by Step (Day 2) Still using "new" in Spring? ❌ 👉 Then you’re missing the core idea of Spring 💡 What is a Spring Bean? A Bean is: 👉 Any object managed by the Spring IoC container Instead of: UserService service = new UserService(); Spring does: ✔ Create objects ✔ Manage lifecycle ✔ Connect components 💡 What is IoC (Inversion of Control)? 👉 You don’t control object creation anymore 👉 Spring does it for you This leads to: ✔ Cleaner code ✔ Loose coupling ✔ Better scalability 💡 Simple way to think: You: "I will create objects" ❌ Spring: "I will handle everything" ✅ 👉 This is the foundation of Spring Next → Dependency Injection (real magic begins) 🔥 #Spring #SpringBoot #Java #Backend #LearningInPublic