Choosing between @Component and @Bean in Spring Framework

🔹 Spring Scopes in a Nutshell Session bean → Singleton dependency ✅ Each user gets their own session bean All share the same singleton Singleton → Session dependency ❌ Singleton can’t directly hold a session bean Spring injects a proxy (like a mailbox) When the singleton calls a method, the proxy delivers it to the correct session bean for the current user 💡 Analogy: Session → Singleton: each user has their notebook, everyone uses the same pen ✍️ Singleton → Session: singleton talks to a mailbox, which routes messages to the right notebook 📬 Mix scopes carefully — proxies make it safe! #SpringBoot #Java #SessionScope #Singleton #BackendEngineering #SpringTips

🎯 Using @Qualifier in Spring When multiple beans of the same type exist, @Qualifier helps specify which bean should be injected. It works hand-in-hand with @Autowired to resolve dependency conflicts. This ensures clear control over which implementation is wired into the application. 🎛️ #SpringFramework #SpringBoot #Java #Qualifier #DependencyInjection #SoftwareDevelopment

💡𝗝𝗮𝘃𝗮 𝗧𝗶𝗽/𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 𝐓𝐢𝐩 - 𝗜𝗻𝘀𝘁𝗮𝗻𝗰𝗲𝗼𝗳 𝗣𝗮𝘁𝘁𝗲𝗿𝗻 𝗠𝗮𝘁𝗰𝗵𝗶𝗻𝗴 🔥 💎 𝗪𝗵𝗮𝘁 𝗶𝘀 𝗶𝘁? Pattern matching with instanceof (Java 16+) lets you test an object's type AND declare a new variable in one step. When the pattern matches, the variable is automatically cast and assigned. This eliminates redundant casting and makes your code more concise. ✅ 𝗞𝗲𝘆 𝗕𝗲𝗻𝗲𝗳𝗶𝘁𝘀 ◾ Combines type checking and variable declaration in a single expression. ◾ Eliminates explicit casting and reduces boilerplate code. ◾ Prevents ClassCastException with compile-time safety. ⚡ 𝗖𝗼𝗺𝗺𝗼𝗻 𝗨𝘀𝗲 𝗖𝗮𝘀𝗲𝘀 ◾ Type checking in if statements: if (obj instanceof String str). ◾ Switch expressions with pattern matching (Java 21+). ◾ Processing collections with different element types. 🤔 Do you use pattern matching in your code? #java #springboot #programming #softwareengineering #softwaredevelopment

Spring Container & Component Scanning The Spring Container manages object creation, wiring, and bean lifecycle. It reads configuration metadata to build your application structure. Using @ComponentScan, Spring auto-detects beans in specified packages. Together, they enable clean, modular, and maintainable applications. #SpringFramework #Java #SoftwareEngineering #BackendDevelopment

🧠 Pattern Matching for instanceof — The Smallest Change with the Biggest Impact ⚡ We’ve all written code like this 👇 if (obj instanceof String) { String s = (String) obj; System.out.println(s.toUpperCase()); } Looks fine, right? But… do we really need that extra type cast? 🤔 --- 💡 Enter Pattern Matching (Java 16+) Now Java lets you do this: if (obj instanceof String s) { System.out.println(s.toUpperCase()); } No manual casting. No extra line. Just clean, modern, and type-safe ✅ --- 🚀 Why It’s a Game Changer ✨ Reduces boilerplate and improves readability 🔒 Avoids accidental ClassCastException #Java #Java17 #CleanCode #SoftwareEngineering #BackendDevelopment #CodeQuality #ModernJava

#100DaysOfCode – Day 80 Reverse Linked List Problem: Given the head of a singly linked list, reverse the list and return the reversed version. Example: Input: [1, 2, 3, 4, 5] Output: [5, 4, 3, 2, 1] My Approach: Used an iterative method to reverse the list efficiently by manipulating pointers. Initialized three pointers prev, temp, and front. Iteratively reversed each node’s direction until the end of the list was reached. Returned prev as the new head of the reversed list. Time Complexity: O(N) Space Complexity: O(1) Reversing a linked list might look tricky at first, but once you understand pointer manipulation it’s pure logic and flow. #takeUforward #100DaysOfCode #DSA #Java #ProblemSolving #LeetCode #LinkedList #Pointers #CodeNewbie

When we deal with strings, we often forget that not all “strings” behave the same way behind the scenes. 💡 Here’s what I discovered while exploring them deeply 👇 🔹 StringBuffer — synchronized and thread-safe, designed for use in multithreaded environments. It ensures safety when multiple threads modify the same string, but that makes it a bit slower. 🔹 StringBuilder — faster and more efficient, but not thread-safe. Perfect for single-threaded applications where speed matters more than synchronization. Both are mutable (unlike the String class), meaning they allow modification without creating a new object — a key advantage when working with dynamic or frequently changing text. 🚀 This small concept plays a big role in writing optimized Java code — especially when building high-performance applications. #Java #LearningJourney #FullStackDeveloper #StringBuffer #StringBuilder #CodingInJava #JavaConcepts

⚙️ Bean Lifecycle in Spring Every Spring bean goes through stages like instantiation, dependency injection, initialization, and destruction. Developers can customize these steps using lifecycle annotations such as @PostConstruct and @PreDestroy. Spring automatically manages this entire lifecycle, ensuring optimal resource handling and clean object management. 🔁 #SpringBoot #SpringFramework #Java #SpringBeans #Lifecycle #BackendDevelopment

@Primary & @Qualifier When multiple beans of the same type exist, confusion occurs. @Primary marks the default bean Spring should inject automatically. @Qualifier chooses the exact bean when multiple options exist. It provides precise dependency control during injection. Both avoid ambiguity and ensure stable configurations. #SpringFramework #Java #SoftwareEngineering #BackendDevelopment