Jānis Ošs’ Post

🟢 Spring Boot Tip: Mastering Profiles for Cleaner Environment Configuration If you’ve worked with Spring Boot across different environments (local, staging, production), you’ve probably run into configuration headaches. That’s where Profiles come in—they’re a simple but powerful way to keep things organized and flexible. At a high level, profiles let you tailor your application’s behavior depending on where it’s running—without touching your code. 🔍 How it works in practice: You can split configurations into files like application-dev.yml or application-prod.yml Switch between them using spring.profiles.active, environment variables, or command-line flags Load specific beans only when needed using @Profile Map configuration cleanly into Java objects using @ConfigurationProperties 💡 What makes this really powerful? Spring Boot doesn’t just read one config—it layers multiple sources and decides which values win. For example: ➡️ Command-line arguments ➡️ Environment variables ➡️ Profile-specific configs ➡️ Default application.yml This order ensures flexibility while still allowing overrides when needed. 🛠️ Best practices I follow: ✔️ Keep application.yml for common/shared settings ✔️ Use profile-specific files only for differences between environments ✔️ Never store secrets in your codebase—use environment variables or a config service ✔️ Add fallback values using @Value to avoid runtime surprises ✔️ For larger systems, look into centralized config solutions like Spring Cloud Config ⚠️ Common pitfalls to avoid: Mixing environment-specific values into the main config file Assuming all configs behave equally (profile files always override defaults) Done right, profiles make your application easier to manage, safer to deploy, and much more scalable as your system grows. #SpringBoot #Java #BackendDevelopment #SoftwareEngineering #CleanCode #DevOps

REST API design is more than just mapping endpoints. Working with Spring Boot has taught me that the best APIs are the ones that feel "invisible" because they are so intuitive. Here is how I’m building that bridge: ◈ Meaningful and resource-based endpoint naming ◈  Proper use of HTTP methods (GET, POST, PUT, DELETE) ◈ Consistent request and response structure ◈ Using appropriate HTTP status codes ◈ Basic validation and clear error messages A clean API simplifies integration and saves hours of debugging down the road. Still learning, still building! 🛠️ #Java #SpringBoot #RESTAPI #BackendDevelopment #Microservices #SoftwareEngineering #CleanCode #WebDevelopment #APIDesign #SystemDesign #JavaDeveloper #TechUpdate

🚀 Spring Boot – Understanding @Service & @Autowired Today I focused on how Spring Boot manages application layers and dependencies. 🧠 Key Learnings: 🔹 @Service → Defines the business logic layer 🔹 @Autowired → Automatically injects dependencies 💡 This enables smooth communication between Controller → Service without manually creating objects. 🔥 Why it matters: - Promotes clean architecture - Reduces tight coupling - Makes applications scalable and maintainable --- 🧠 DSA Practice (Consistency): ✔️ First Repeating Character ✔️ Reverse Words in String --- 👉 Answer: @Autowired is used to inject dependency automatically #SpringBoot #Java #BackendDevelopment #Microservices #LearningJourney

🚀 30 Days of Spring Boot – Day 1 Today I covered the core fundamentals of Spring & Spring Boot 👇 🔹 What is Spring? A powerful Java framework used to build scalable and enterprise applications with features like IoC and DI. 🔹 What is Spring Boot? An extension of Spring that makes development faster with auto-configuration, embedded servers, and minimal setup. 🔹 IoC (Inversion of Control) Spring manages object creation and lifecycle instead of developers doing it manually. 🔹 Dependency Injection (DI) Dependencies are injected by Spring → making code loosely coupled and easy to test. 💡 Built a small project using: @Component @Service @Autowired ✔ Layered architecture (Controller → Service → Component) 📌 Key Learning: Don’t create objects manually — let Spring handle it! #SpringBoot #Java #BackendDevelopment #Microservices #LearningJourney #30DaysChallenge #Developers #Coding

I’ve been revisiting how we structure service layers in Spring Boot, and it’s interesting how often we default to simple @Service classes without questioning long-term flexibility. At small scale, that works perfectly fine. But as systems grow, the lack of abstraction starts to show — especially around testing, swapping implementations, and keeping domain logic clean. One thing I’ve been thinking about recently is where the line actually is between “simple and enough” vs “structured for change”. There’s no single right answer — it really depends on the stage of the system. Curious how others approach this: do you introduce interfaces early, or only when needed? youtube: https://lnkd.in/dZB-VUyc #SpringBoot #BackendDevelopment #SoftwareEngineering #java #spring #softwaredevelopers #engineers #cleancode #cleanArchitecture

For all Dev Lerners Id recommed you check out this Gurus /Mkurugenzi minisodes to grow . A great way to learn

Spring vs Spring Boot (Real Difference 🔥) At first, I thought Spring = Spring Boot 🤯 But today I learned something interesting 👇 💡 Spring (Framework) Requires manual configuration Need to setup server (Tomcat) More boilerplate code Slower project setup 💡 Spring Boot (Built on Spring) Auto-configuration ⚡ Embedded server (Tomcat/Jetty) Minimal code & setup Quick project start ⚡ More Important Differences (🔥 Value Add): 👉 Dependency Management Spring → manually add dependencies Spring Boot → uses Starter dependencies (easy) 👉 Configuration Spring → XML / complex config Spring Boot → mostly no config / application.properties 👉 Run Application Spring → deploy WAR on server Spring Boot → run as standalone JAR (just run main method) 👉 Production Ready Spring → need extra setup Spring Boot → built-in features (Actuator, metrics) 👉 Microservices Spring → possible but complex Spring Boot → best for microservices 🏬 Simple Example: Spring = Build everything manually 🏗️ Spring Boot = Ready setup 🚀 📌 Key Takeaways: Spring = base framework Spring Boot = faster development Boot removes configuration pain Boot is widely used in real projects 💡 One line I learned: 👉 Spring Boot = Spring + Speed + Simplicity #Spring #SpringBoot #Java #BackendDevelopment #LearningInPublic #30DaysOfCode #Developers

Custom Starter in Spring Boot — Advanced concept 🚀 Yes, you can create your own Spring Boot starter! Example use case: 👉 Common logging module 👉 Shared security config 👉 Reusable utilities Steps 👇 1️⃣ Create auto-configuration class 2️⃣ Use @Configuration 3️⃣ Add spring.factories 💡 Why it matters: ✔ Reusability ✔ Cleaner microservices ✔ Standardization across projects 🔥 Real-world: Companies use custom starters for shared libraries This is next-level Spring Boot knowledge 💯 #SpringBoot #Java #AdvancedJava

🚀 Day 3 — Spring vs Spring Boot (Real Difference 🔥) At first, I thought Spring = Spring Boot 🤯 But today I learned something interesting 👇 💡 Spring (Framework) Requires manual configuration Need to setup server (Tomcat) More boilerplate code Slower project setup 💡 Spring Boot (Built on Spring) Auto-configuration ⚡ Embedded server (Tomcat/Jetty) Minimal code & setup Quick project start ⚡ More Important Differences (🔥 Value Add): 👉 Dependency Management Spring → manually add dependencies Spring Boot → uses Starter dependencies (easy) 👉 Configuration Spring → XML / complex config Spring Boot → mostly no config / application.properties 👉 Run Application Spring → deploy WAR on server Spring Boot → run as standalone JAR (just run main method) 👉 Production Ready Spring → need extra setup Spring Boot → built-in features (Actuator, metrics) 👉 Microservices Spring → possible but complex Spring Boot → best for microservices 🏬 Simple Example: Spring = Build everything manually 🏗️ Spring Boot = Ready setup 🚀 📌 Key Takeaways: Spring = base framework Spring Boot = faster development Boot removes configuration pain Boot is widely used in real projects 💡 One line I learned: 👉 Spring Boot = Spring + Speed + Simplicity 💬 Which one do you prefer for projects — Spring or Spring Boot? 👇 Day 3 done ✅ #Spring #SpringBoot #Java #BackendDevelopment #LearningInPublic #30DaysOfCode #Developers

𝗠𝗮𝘀𝘁𝗲𝗿 𝗦𝗽𝗿𝗶𝗻𝗴 𝗔𝗢𝗣 𝗮𝗻𝗱 𝗦𝘁𝗼𝗽 𝗥𝗲𝗽𝗲𝗮𝘁𝗶𝗻𝗴 𝗬𝗼𝘂𝗿𝘀𝗲𝗹𝗳 Repetitive "boilerplate" code is the silent killer of clean architectures. In Spring Boot development, we often see service layers drowning in code that has nothing to do with the actual business logic. Things like:  • 📝 Logging method entry and exit.  • 🛡️ Security/Permission checks.  • ⏱️ Performance monitoring (measuring execution time).  • 🔄 Cache eviction management. If you are manually adding this logic to every service method, you’re creating a maintenance nightmare. 𝗧𝗵𝗲 𝗦𝗼𝗹𝘂𝘁𝗶𝗼𝗻: Spring Aspect-Oriented Programming (AOP). 𝗔𝗢𝗣 lets you separate these "Cross-Cutting Concerns" from your business logic. You write the logic once in an 𝗔𝘀𝗽𝗲𝗰𝘁, and Spring automatically applies it whenever specific methods are called. Your Service class remains clean, readable, and focused on one responsibility. How It Works (Example): Instead of copying 𝗹𝗼𝗴𝗴𝗲𝗿.𝗶𝗻𝗳𝗼(...) into every method, you create a single Logging 𝗔𝘀𝗽𝗲𝗰𝘁 like the one below. Using @𝗔𝗿𝗼𝘂𝗻𝗱 advice, you can intercept the method call, start a timer, execute the actual method, and then log the result. The Benefits: ✅ 𝗗𝗥𝗬 𝗣𝗿𝗶𝗻𝗰𝗶𝗽𝗹𝗲: Write logic once, use it everywhere. ✅ 𝗗𝗲𝗰𝗼𝘂𝗽𝗹𝗶𝗻𝗴: Business logic doesn’t know (or care) about logging/monitoring. ✅ 𝗙𝗹𝗲𝘅𝗶𝗯𝗶𝗹𝗶𝘁𝘆: Enable or disable cross-cutting features easily. 🛑 𝗖𝗿𝗶𝘁𝗶𝗰𝗮𝗹 𝗧𝗶𝗽: 𝗧𝗵𝗲 𝗣𝗿𝗼𝘅𝘆 𝗧𝗿𝗮𝗽! When using Spring AOP (by default), Spring creates a dynamic proxy object around your target class. The AOP logic only executes when you call the method through that proxy. 𝗧𝗵𝗶𝘀 𝗺𝗲𝗮𝗻𝘀: If 𝙈𝙚𝙩𝙝𝙤𝙙𝘼() inside your Service class calls 𝙈𝙚𝙩𝙝𝙤𝙙𝘽() (which is also inside the same class), the call is internal and bypasses the proxy. Your AOP advice for 𝙈𝙚𝙩𝙝𝙤𝙙𝘽() will NOT run. Knowing this subtle nuance is what separates Spring experts from beginners! How are you using AOP in your Spring Boot applications? Share your best use cases below! 👇 #SpringBoot #Java #SoftwareArchitecture #CodingBestPractices #BackendDev