Spring Boot External Configuration with application.properties and @ConfigurationProperties

🚀 Spring Boot Learning Update | Reducing Boilerplate Code with Lombok Today I explored how to write cleaner and more maintainable Java code in Spring Boot projects by simplifying repetitive class code. In many Java applications, we often write the same kind of code again and again: • Getters • Setters • Constructors • toString() methods\ This repetitive code increases file size, reduces readability, and slows development. So today I implemented a Spring Boot project where these common tasks were handled in a smarter and cleaner way using Lombok. What I Learned: ✅ How to reduce boilerplate code in model/component classes ✅ How to keep classes clean and readable ✅ Faster development with less manual coding ✅ Better maintainability in real-world Spring Boot projects ✅ Cleaner project structure for production-level applications Project Flow: • Created a Spring Boot application • Added a component class with fields • Injected object into runner class • Set values and printed output successfully • Verified that the application runs perfectly with cleaner code structure Why This Matters: Writing less unnecessary code means focusing more on business logic and application design. Clean code is not just about looks — it improves productivity and maintainability. Thank you Prasoon Bidua Sir for your guidance and teaching. Every small concept learned today becomes a strong foundation for tomorrow’s backend development journey. #SpringBoot #Java #Lombok #BackendDevelopment #CleanCode #JavaDeveloper #CodingJourney #LearningInPublic #Programming #SoftwareDevelopment

🚀 Spring Boot Learning Series – Day 2 Continuing my Spring Boot learning journey. Today I learned about Maven, Spring Boot project structure, and the internal working of a Spring Boot application. 🔹 What I learned today: • What is Maven and how it works • pom.xml and dependency management • Structure of Spring Boot application • Spring Boot application internal working • IOC (Inversion of Control) Container • Dependency Injection 🔹 Annotations I learned: • @SpringBootApplication • @Component • @ComponentScan • @EnableAutoConfiguration • @Configuration • @Autowired 💡 My Understanding: When we run a Spring Boot application, the SpringApplication.run() method starts the application, creates the IOC container, creates beans, performs dependency injection, and starts the embedded Tomcat server. Also learned that @SpringBootApplication is a combination of: @Configuration @EnableAutoConfiguration @ComponentScan Understanding how Spring manages objects using IOC and Dependency Injection was very interesting today. Looking forward to learning about REST controllers and APIs in more detail. #SpringBoot #Java #BackendDevelopment #LearningJourney #DependencyInjection #SoftwareDevelopment

🚀 My Spring Boot Learning Journey with Vipul Tyagi's YouTube playlist. 🧑💻 Over the past 2 weeks, I’ve been diving into Spring Boot, and I wanted to share what truly worked for me. I followed the amazing content from Engineering Digest, created by Vipul Tyagi. Specifically, this playlist 👉 Spring Boot Mastery: From Basics to Advanced 💡 Why this stood out: Covers fundamentals → advanced topics in a structured way Clear explanations with practical examples Focus on real-world understanding, not just theory 🛠️ What I did differently: Instead of just watching, I built a code-along project alongside the playlist — which made a huge difference in retention and confidence. 📂 Here’s the project I created: 👉 https://lnkd.in/dhcgxGtG It helped me: ✅ Understand core Spring Boot concepts deeply. ✅ Get hands-on with REST APIs, Security, Architecture, and best practices. ✅ Build something tangible while learning. ✅ Deploy the developed code-along project to railway.app 💭 My takeaway: If you're learning Spring Boot, don’t just consume content, build along with it. That’s where real learning happens. 👏 Huge thanks to Vipul Tyagi for creating such valuable content. This course has 47 videos as of now, and it is completely free and, most importantly, far better than many paid courses. If you're starting your Spring Boot journey, I highly recommend checking this out! https://lnkd.in/dkxHk_U3 #SpringBoot #Java #BackendDevelopment #OpenSource #SoftwareDevelopment #Developers #Programming

🚀 #Day85 of My Java Learning! Today I explored Spring Boot, a powerful framework that simplifies building Java applications quickly and efficiently. ✨ 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭? ➜ Spring Boot is an extension of the Spring Framework used to build standalone applications with minimal configuration ➜ It eliminates complex setup and allows developers to focus on business logic ➜ Comes with embedded servers like Tomcat 📌 𝐁𝐞𝐧𝐞𝐟𝐢𝐭𝐬 𝐨𝐟 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 ➜ Auto Configuration → Automatically configures application based on dependencies ➜ Standalone Applications → No need for external servers ➜ Embedded Servers → Comes with Tomcat, Jetty ➜ Less Boilerplate Code → Reduces XML configuration ➜ Fast Development → Quick project setup using Spring Initializr ➜ Production Ready → Built-in features like monitoring and metrics ✨ 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 𝐏𝐫𝐨𝐣𝐞𝐜𝐭 𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞 A typical Spring Boot project follows a clean structure: ➜ 𝐬𝐫𝐜/𝐦𝐚𝐢𝐧/𝐣𝐚𝐯𝐚 • Contains main application code ➜ 𝐜𝐨𝐧𝐭𝐫𝐨𝐥𝐥𝐞𝐫 • Handles user requests ➜ 𝐬𝐞𝐫𝐯𝐢𝐜𝐞 • Contains business logic ➜ 𝐫𝐞𝐩𝐨𝐬𝐢𝐭𝐨𝐫𝐲 • Interacts with database ➜ 𝐞𝐧𝐭𝐢𝐭𝐲 • Represents database tables ➜ 𝐫𝐞𝐬𝐨𝐮𝐫𝐜𝐞𝐬 • application.properties / application.yml ➜ 𝐦𝐚𝐢𝐧 𝐜𝐥𝐚𝐬𝐬 • Entry point (@SpringBootApplication) ✨ 𝐒𝐩𝐫𝐢𝐧𝐠 𝐯𝐬 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 🔹 𝐒𝐩𝐫𝐢𝐧𝐠 𝐅𝐫𝐚𝐦𝐞𝐰𝐨𝐫𝐤 • Requires manual configuration • Needs external server setup • More setup time • Suitable for complex configurations 🔹 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭 • Auto configuration • Embedded server • Minimal setup • Faster development ➜ Spring → More control ➜ Spring Boot → More convenience 📌 𝐖𝐡𝐚𝐭 𝐈 𝐋𝐞𝐚𝐫𝐧𝐞𝐝 𝐓𝐨𝐝𝐚𝐲 🔹 How Spring Boot simplifies Spring applications 🔹 Importance of auto-configuration 🔹 Understanding project structure 🔹 Difference between Spring and Spring Boot 🔹 How real-world apps are built faster using Spring Boot 💡 𝐊𝐞𝐲 𝐓𝐚𝐤𝐞𝐚𝐰𝐚𝐲 Spring Boot makes development faster, simpler, and production-ready by reducing configuration and focusing on code. 10000 Coders | Gurugubelli Vijaya Kumar #Java #SpringBoot #BackendDevelopment #JavaDeveloper #LearningJourney #100DaysOfCode

Continuing my Spring Boot learning series, I want to go beyond how exception handling is implemented and focus on why it actually matters in real-world systems. ⚠️ The real problem I faced In one of my projects, I had implemented exception handling—but not in a well-structured, centralized way. At one point, a failure occurred in a service layer due to an unexpected runtime exception. What followed wasn’t just an error—it exposed deeper issues in my design: - The API returned inconsistent and sometimes empty responses - There was no clear mapping to HTTP status codes - Logs didn’t provide enough context to trace the root cause - Debugging required jumping across multiple layers of the application The issue itself wasn’t complex—but identifying it took significantly longer than fixing it. 🔍 What this revealed The problem wasn’t the exception—it was the lack of a consistent strategy to handle failures. Without centralized exception handling: - Each layer behaves differently under failure - Errors lose context as they propagate - Observability becomes weak - Small bugs turn into time-consuming debugging sessions ✅ What I changed I moved to a centralized exception handling approach using @RestControllerAdvice, along with: - Standardized error response structure - Clear HTTP status code mapping - Proper logging at a single point - Custom exceptions for domain-specific scenarios 🚀 Impact after fixing it - Faster debugging due to better traceability - Consistent API responses across all endpoints - Cleaner controller and service layers - Improved reliability and maintainability 💡 Key takeaway Exception handling is not just about preventing crashes—it’s about making failures observable, predictable, and manageable. In real systems, the difference between a good and bad implementation is not whether exceptions are handled—but how clearly and consistently failures are communicated and traced. Next, I’m planning to explore Caching in Spring Boot. #SpringBoot #Java #BackendDevelopment #ExceptionHandling #SystemDesign #LearningInPublic #SoftwareEngineering

🚨 Stop Learning Spring Boot Like This ❌ (Do This Instead) Most developers are stuck. Not because they’re not learning… But because they’re learning the WRONG way. --- Let me guess 👇 👉 Watching endless tutorials 👉 Building only CRUD apps 👉 Copy-pasting code 👉 Still not confident in interviews --- 💥 Here’s the truth: Companies don’t care how many tutorials you watched. They care about how well you can build real systems. --- 👉 If you’re only doing CRUD… 👉 You’re NOT learning Spring Boot properly. --- 🎯 What you SHOULD do instead: ✔ Understand fundamentals deeply ✔ Build real-world features (JWT, logging, security) ✔ Think like a backend engineer — not a tutorial follower --- I broke this down in my latest video 👇 🎥 https://lnkd.in/djwT3muq --- 💡 Remember: 👉 Don’t chase tutorials… 👉 Build real skills That’s what gets you hired. --- If you’re serious about backend development, follow for more 🚀 Follow Narendra Sahoo for more Subscribe the channel and stay tune #SpringBoot #JavaDeveloper #BackendDevelopment #Programming #SoftwareEngineering #Microservices #CareerGrowth

What I wish I knew before learning Spring Boot 🚀 When I first started learning Java backend development, I kept hearing about Spring and Spring Boot… And honestly? I was confused. I thought: 👉 “Are they the same thing?” 👉 “Which one should I learn first?” After struggling for a while, here’s what I finally understood: 🔹 Spring Framework - Powerful, but requires a lot of manual configuration - XML files, setup, and boilerplate code 🔹 Spring Boot - Built on top of Spring - Removes most of the setup headaches - Gives you a ready-to-run project with minimal configuration 💡 The biggest realization: Spring Boot is not something different — it makes Spring easier to use. 💥 What I would do if I started again: ✔️ First, build strong Java + OOP basics ✔️ Then directly start with Spring Boot ✔️ Learn concepts like Dependency Injection along the way 📌 My advice to beginners: Don’t get stuck trying to understand everything at once. Start building projects — clarity comes with practice. #Java #SpringBoot #BackendDevelopment #LearningInPublic #100DaysOfCode

Spent the better part of my day migrating a long-term project from Spring Boot v3 to v4 and honestly, I’m just glad it worked out 😅 I went in expecting things to break… and they did. But that’s where the learning happened. Here’s how I approached it: I started with the official Spring Boot migration guide. That’s where I came across "spring-boot-starter-classic" essentially a “mother package” that bundles multiple starters. It’s particularly useful when dealing with large migrations where different versions of dependencies may need to coexist. I also discovered "spring-boot-properties-migrator", which turned out to be incredibly helpful. It provides backward compatibility for old configuration properties and flags deprecated ones at runtime. It’s meant to be temporary though… and yes, I forgot to remove it 😅 (shoutout to CodeRabbit for catching that in my PR). Next, I bootstrapped a fresh project using start.spring.io with v4.0.5 and mirrored my dependencies. The goal was simple: compare the new "pom.xml" with my existing one and identify what changed. A few interesting findings: - "spring-boot-starter-web" is now "spring-boot-starter-webmvc" - Some dependencies I previously managed manually now have official starter packages (always the better option when available to avoid version conflicts) After updating my "pom.xml", I ran the build… and of course, it failed. Digging in, I found two major breaking changes: - Jackson packages moved from "com.fasterxml.jackson.*" to "tools.jackson.*" (with exceptions like annotations) - Some datetime-related configuration properties had changed Thankfully, the properties migrator pointed me in the right direction, and the docs filled in the gaps. Overall, this was one of those “break things, fix things, understand things” kind of days. Learned a lot, documented it for future me (and maybe someone else out there), and surprisingly… had fun doing it. Side note: I was partly inspired after watching a Netflix engineering talk on their 2026 Java stack and agentic migration approach. Solid stuff. Cheers 🥂 #java #springboot #backend

Building production-ready APIs with Spring Boot While learning backend development, I’ve been focusing on three concepts that seem simple — but are critical in real-world applications: 🔹 Pagination In production, you’re not dealing with 10 records — you’re dealing with thousands (or millions). Pagination ensures performance stays stable, reduces memory usage, and improves response time. 🔹 Custom Exceptions Generic errors don’t help anyone. Custom exceptions make debugging easier, prevent exposing sensitive details, and give meaningful feedback to API consumers. 🔹 Custom Response DTOs A consistent API response structure is a game changer. It improves maintainability, creates a clear contract between frontend & backend, and makes scaling much smoother. 💡 What I’m learning: Writing code that works is one thing. Writing code that scales, is maintainable, and production-ready is a whole different level. Still learning. Still building. ⚙️ #SpringBoot #Java #BackendDevelopment #APIDesign #SoftwareEngineering #LearningInPublic

🚀 Day 7 of Learning Spring Boot — and today was all about writing BETTER code, not just working code. Built two real features today: ✅ Get Product by ID ✅ Search Products by keyword But the biggest lesson wasn't about features — it was about HOW you write them. 🔴 I used to write this: product = service.getProductById(id).get(); if(product != null) { ... } Looks fine, right? WRONG. If the product doesn't exist, .get() throws a NoSuchElementException and the null check never even runs. It's literally dead code. 😅 🟢 The correct way using Optional: service.getProductById(id)  .map(p -> ResponseEntity.ok(p))  .orElseGet(() -> ResponseEntity.notFound().build()); Clean. Safe. No crashes. This is how pros use Optional. 🔑 Golden Rule I learned today: NEVER call .get() directly on an Optional. Always use .map(), .orElse(), or .orElseGet() --- Also built a Search API that matches keyword across name, brand, description & category — all case-insensitive using JPQL LIKE queries. 🔍 And learned a subtle but important Spring MVC rule: 👉 Always define specific routes like /products/search BEFORE dynamic ones like /products/{id} — otherwise Spring treats "search" as an ID. 🤦 Github Repo : https://lnkd.in/g5aeACUU Small mistakes, big lessons. That's what Day 7 looked like. 💪 #SpringBoot #Java #100DaysOfCode #LearningInPublic #BackendDevelopment #JavaDeveloper #SpringFramework