Ashish Deshmukh’s Post

🚀 Day 7 — What is Bean? (Core Spring Concept 🔥) Today I understood one important thing… 👉 Everything in Spring is a Bean 💡 What is a Bean? 👉 A Bean is an object created and managed by Spring (IoC container) (Simple: Spring creates object, we just use it) ⚙️ How Spring Creates Bean? Using XML (<bean>) Using Annotations (@Component, @Service) 👉 Spring container creates, manages, and injects beans ⚡ Bean Scope (Important 🔥) 🔹 Singleton (default) 👉 Only ONE object created 🔹 Prototype 👉 New object every time 🔍 Bean Lifecycle (Simple Flow) 👉 Create → Initialize → Use → Destroy 💡 One line I learned: 👉 In Spring, objects are called Beans and Spring manages them 💬 Which scope confused you — Singleton or Prototype? Day 7 done ✅ #Spring #Java #BackendDevelopment #LearningInPublic #30DaysOfCode #SpringBoot #Developers

#java #springboot #tips 🚫 Stop using field injection in Spring Boot. Here’s why: Most developers write this: @Autowired private UserService userService; ✅ Use constructor injection instead: @Service @RequiredArgsConstructor public class OrderService { private final UserService userService; // immutable + testable } Why it matters: • Fields are final → truly immutable • Easier to unit test without Spring context • Fails fast at startup if bean is missing • Works perfectly with Lombok’s @RequiredArgsConstructor This is also the official Spring recommendation since Spring 4.x. #Java #SpringBoot #CleanCode #BackendDev

🌱 Behind every powerful Spring Boot application lies a strong foundation — the Spring Core Frameworks. Most developers jump directly into Spring Boot, but understanding the core modules gives you a real edge in backend development. 🔹 Spring Core – IoC & Dependency Injection🔹 Spring Beans – Object lifecycle management🔹 Spring AOP – Logging, security, transactions🔹 Spring Context – Application configuration & events🔹 SpEL – Dynamic expressions & querying🔹 Spring Instrumentation – Class loading & monitoring Mastering these concepts helps you write cleaner code, build scalable systems, and crack interviews with confidence 🚀Strong applications are built on strong foundations. Which Spring module helped you the most in your journey? 👇 .... .... .... #SpringFramework #SpringBoot #Java #BackendDevelopment #SoftwareEngineering #Developers #Programming #TechLearning #JavaDeveloper #CodingJourney #Microservices #SystemDesign #LearnJava #SpringCore #TechCareer

What’s your go-to approach for dynamic search in Spring Boot? 🤔 When it comes to JPA Specifications vs @Query most developers get this decision wrong. ❌ Here’s how to actually choose the right one 👇 #SpringBoot #Java #SoftwareEngineering

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

What is @RestController in Spring Boot? 🚀 It is a combination of: @Controller + @ResponseBody 👉 It directly returns JSON response Example: @RestController public class Test {   @GetMapping("/hello")   public String hello() {     return "Hello";   } } Simple, clean, and perfect for APIs. Are you using Spring Boot in your project? #SpringBoot #Java #BackendDeveloper

🚀 What happens inside Spring Framework when your application starts? From bootstrapping to dependency injection, here’s a complete step-by-step flow of how Spring works internally. Understanding this flow helps developers write better and optimized applications. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering

Spring Boot Custom Argument Resolver 🚀 Want to inject custom objects into controller automatically? You can 👇 public class UserArgumentResolver implements HandlerMethodArgumentResolver { @Override public boolean supportsParameter(MethodParameter parameter) { return parameter.getParameterType().equals(User.class); } @Override public Object resolveArgument(...) { return getUserFromToken(); } } 💡 Use case: ✔ Extract user from JWT ✔ Avoid repeated code in controllers 👉 Clean & powerful approach 🔥 Real-world: Used in production for authentication context This is advanced Spring Boot design 💯 #SpringBoot #Java #Backend

🚀 Understanding Dependency Injection in Spring Boot As a Java Backend Developer, one concept that truly changed how I design applications is Dependency Injection (DI). 👉 What is Dependency Injection? Dependency Injection is a design pattern in which an object receives its dependencies from an external source rather than creating them itself. This helps in building loosely coupled, testable, and maintainable applications. Instead of: ❌ Creating objects manually inside a class We do: ✅ Let the framework (like Spring Boot) inject required dependencies automatically 💡 Types of Dependency Injection in Spring Boot 1️⃣ Constructor Injection (Recommended) Dependencies are provided through the class constructor. ✔ Promotes immutability ✔ Easier to test ✔ Ensures required dependencies are not null 2️⃣ Setter Injection Dependencies are set using setter methods. ✔ Useful for optional dependencies ✔ Provides flexibility 3️⃣ Field Injection Dependencies are injected directly into fields using annotations like @Autowired. ✔ Less boilerplate ❌ Not recommended for production (harder to test & maintain) 🔥 Why use Dependency Injection? ✔ Loose coupling ✔ Better unit testing ✔ Cleaner code architecture ✔ Easy to manage and scale applications 📌 In modern Spring Boot applications, Constructor Injection is considered the best practice. 💬 What type of Dependency Injection do you prefer and why? #Java #SpringBoot #BackendDevelopment #SoftwareEngineering #CleanCode #DependencyInjection

Spring Boot @Bean vs @Component — Hidden difference 🔥 Both create beans… but NOT the same 👇 ✅ @Component - Auto-detected via component scan - Used for your own classes ✅ @Bean - Defined manually inside @Configuration - Used for third-party classes Example: @Bean public ObjectMapper objectMapper() { return new ObjectMapper(); } 💡 Why it matters: ✔ Better control over bean creation ✔ Custom configuration 👉 Use @Bean when you need flexibility Small concept → big design impact 💯 #SpringBoot #Java #Backend