Building robust APIs with Spring Boot and Java

@Autowired vs @Inject Many developers use @Autowired and @Inject interchangeably — but do you know the difference? Let’s clear the confusion 👇 🔹 @Autowired (Spring-specific) Comes from Spring Framework (org.springframework.beans.factory.annotation.Autowired). Supports required=false, allowing optional dependency injection. Can be used on constructors, fields, and setters. Tight coupling with Spring — not portable outside the framework. 🔹 @Inject (Java Standard) Comes from JSR-330 (javax.inject.Inject) — part of standard Java dependency injection. No required attribute. Works similarly to @Autowired when using Spring, but promotes loose coupling and framework independence. ✅ Best Practice: If your project is Spring-only → use @Autowired. If you aim for framework independence or future migration → prefer @Inject. 💬 What annotation do you prefer using in your Spring projects — and why? #Java #SpringBoot #DependencyInjection #CodingTips #BackendDevelopment #SpringFramework

Project Loom is Here: Stop Writing Thread-Blocking Code in Java The arrival of Java Virtual Threads (Project Loom, production-ready since Java (21) is the biggest shift in concurrent design we've seen in years. For a decade, our Spring Boot applications were limited by expensive platform threads, often leading to thread starvation and wasted memory when waiting on I/O (like external REST API calls). This forced us into using complex asynchronous frameworks, trading readability and maintainability for raw throughput. Virtual Threads completely change the game by making threads cheap and abundant and also a million virtual threads can now run on just a few dozen platform threads. The key takeaway: we can now write simple, synchronous, thread-blocking Java code that is both highly readable and incredibly efficient, removing a huge source of backend complexity. This is a major productivity gain for every Full Stack team. This shift has huge implications for our systems. We instantly gain massive increases in concurrency and throughput for I/O-bound microservices without touching complex reactive boilerplate. Our backend latency stabilizes because we eliminate thread starvation, leading to a better user experience on the frontend. The transition is often seamless: you just configure your framework to use a Virtual Thread executor—often requiring zero code changes to your business logic. This simplifies integration: when our Full Stack application calls a slow external API, the Java thread pauses cheaply, not expensively. Have you started testing your existing services with Virtual Threads? Did you see the performance boost right out of the box? #Java #Java21 #ProjectLoom #Concurrency #Springboot #FullStackDeveloper #TechArchitecture #JavaDeveloper #SoftwareDeveloper #SoftwareEngineer #BackendDeveloper #C2C #C2H

𝗝𝗮𝘃𝗮 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄 𝗣𝗿𝗲𝗽𝗮𝗿𝗮𝘁𝗶𝗼𝗻 𝗚𝘂𝗶𝗱𝗲 Part -2 (Harman). 1. What are the disadvantages of a microservices architecture? 2. Explain microservices architecture. 3. What is an API Gateway? Why do we use it? 4. What are the advantages and disadvantages of Spring Boot? 5. How does communication happen between microservices? 6. How do you integrate Kafka with Spring Boot? 7. Explain the purpose of the application.properties file. 8. How do you manage multiple Spring Boot profiles (dev, test, prod)? 9. Explain @ExceptionHandler and the other annotations used for exception handling in Spring. 10. Write code to create a custom exception in Spring Boot. 11. What is a logger, and why is it used in applications? 12. What are the commonly used annotations in Spring? 13. Explain @SpringBootApplication, @Autowired, and @Qualifier. 14. Explain the MVC (Model–View–Controller) architecture. 15. What is the Dispatcher Servlet in Spring MVC? 16. What is the IoC (Inversion of Control) Container? 17. Explain ApplicationContext and BeanFactory. Which one is lazy-loaded and how? 18. Write a custom query to fetch the second highest salary using the @Query annotation. 19. Explain JVM architecture. 20. What is a ClassLoader in Java? 21. What memory areas are present in the JVM? 22. What is the JIT (Just-In-Time) Compiler? 23. What are the Java 8 features? Explain them. 24. What is a marker interface? 25. Explain the OOP (Object-Oriented Programming) concepts. 26. What is compile-time polymorphism and runtime polymorphism? Give examples. 27. Can you override a static method? Explain why or why not. 28. What does immutable mean? Give an example. 29. What are access modifiers in Java? Name the ones available for classes. 30. Write a program to find the total number of different characters in your name along with their counts. #Javadeveloper #java #Springboot #Microservice #Servlet #kafka

🚀 Just published my new Medium article: "Spring Boot Annotations: The Ultimate Developer's Mind Map Guide." If you're building modern Java apps, mastering annotations like @RestController, @Autowired, and @SpringBootApplication is non-negotiable. I've broken down 40+ essential annotations into 9 easy-to-digest categories with clear code examples and a handy mind map overview. #Java #SpringBoot #Annotations #SoftwareDevelopment #Medium

Java excels at backward compatibility and maintaining multiple long-term support (LTS) versions. This allows tool developers and application developers the time needed to update support for newer versions at a pace which works for them. As Enterprise Architects, we must continually update our application's software currency roadmap, taking into account that the dependencies in our solution all move at different speeds. In some cases, it may be to the application's advantage to remove reliance on some dependencies. https://bit.ly/3KYDPKQ

Build REST APIs Like a Pro with Spring Framework! Hey connections! I just uploaded a FREE PDF guide for all aspiring Java developers and backend enthusiasts! In this detailed resource, you'll learn: How to build your API using Spring + Java Configuration How to bootstrap a web application with Spring 50 All about HTTP Message Converters in Spring The power of @RequestBody & @ResponseBody annotations Best practices for Entity to DTO conversion Proper error handling for REST APIs And so much more on building robust, production-ready Spring REST APIS! Whether you're just starting or leveling up your Spring game, this guide is packed with practical knowledge and clean code examples. Check it out, drop a comment if you find it useful, and feel free to share it with your dev circle! Follow for more Manish Kumar Like and share if you found this helpful! #SpringBoot #JavaDeveloper #RESTAPI #Backend Development #SpringFramework #Open ToLearning #LinkedInLearning #Spring5 #JavaConfig #TechCommunity

Looking back, one of the most valuable projects I ever worked on was one where we had to break a large, monolithic Java application into microservices. We started with what seemed like a "simple" piece to carve out: the user profile service. We thought it would be a quick win. We were wrong. We quickly discovered a web of hidden dependencies. The "user" object was tangled up with billing, shipping, marketing preferences, and support tickets. What we thought was a simple data model was actually the core of the entire business. 💡 My Key Takeaway: That project taught me a crucial lesson about coupling. The true complexity of a system isn't in its features; it's in the relationships between its features. Before you can split a monolith, you have to spend just as much time mapping its "seams" as you do writing new code. 🤔 What's a project that looked simple on the surface but taught you a deep architectural lesson? #SoftwareArchitecture #SystemDesign #Java #Microservices #Programming

Build REST APIs Like a Pro with Spring Framework! Hey connections! I just uploaded a FREE PDF guide for all aspiring Java developers and backend enthusiasts! In this detailed resource, you'll learn: How to build your API using Spring + Java Configuration How to bootstrap a web application with Spring 50 All about HTTP Message Converters in Spring The power of @RequestBody & @ResponseBody annotations Best practices for Entity to DTO conversion Proper error handling for REST APIs And so much more on building robust, production-ready Spring REST APIS! Whether you're just starting or leveling up your Spring game, this guide is packed with practical knowledge and clean code examples. Check it out, drop a comment if you find it useful, and feel free to share it with your dev circle! Like and share if you found this helpful! #SpringBoot #JavaDeveloper #RESTAPI #Backend Development #SpringFramework #Open ToLearning #LinkedInLearning #Spring5 #JavaConfig #TechCommunity

🔥 Why Every Java Developer Should Learn Spring Boot Let’s be honest — setting up Java projects used to be painful. XML configs, dependency hell, manual server setup… 😩 Then came Spring Boot — and everything changed. 🚀 Here’s why developers love it: ✅ Zero XML — just annotations and conventions ✅ Auto-configuration makes setup effortless ✅ Integrates easily with JPA, Security, Actuator, Kafka, and more ✅ Microservices-ready by default ✅ Actuator endpoints for health checks & monitoring Spring Boot isn’t just a framework — it’s a productivity powerhouse. It lets you focus on what really matters — writing business logic, not boilerplate. 💻 #SpringBoot #Java #Microservices #BackendDevelopment #SpringFramework #CareerGrowth #Developers #Coding #SoftwareEngineering