Anis Rahman’s Post

🚀 Day 2/30 — Java Journey  🚫 Most beginners think Java = just writing code… But here’s the truth: 👉 If you don’t understand JVM, JRE, and JDK… You’re not learning Java — you’re just guessing. ❌ Let’s fix that in 60 seconds 👇 🔥 JVM vs JRE vs JDK — Explained Like a Developer 🧠 1. JVM (Java Virtual Machine) 👉 The engine that runs your Java code Converts bytecode → machine code Handles memory (Garbage Collection) Makes Java platform independent 💡 Without JVM → Your code is just text, nothing runs. ⚙️ 2. JRE (Java Runtime Environment) 👉 Everything needed to RUN Java programs Includes: ✔ JVM ✔ Core libraries (java.lang, java.util, etc.) 💡 If you only want to run apps → JRE is enough. 🛠️ 3. JDK (Java Development Kit) 👉 Everything needed to BUILD + RUN Java Includes: ✔ JRE ✔ Compiler (javac) ✔ Debugger & tools 💡 If you’re a developer → JDK is mandatory. 🎯 The Real Relationship (Most Important Part) JDK ⊃ JRE ⊃ JVM 👉 JDK = Developer Toolkit 👉 JRE = Runtime Package 👉 JVM = Execution Engine 💥 Real-World Analogy Think of it like this: 🚗 JDK = Car Factory (build cars) 🛣️ JRE = Ready-to-drive car ⚙️ JVM = Engine inside the car 🚀 Why This Matters (Industry Truth) If you skip this: ❌ You won’t understand errors ❌ You’ll struggle with performance ❌ You’ll fail interviews If you understand this: ✅ You think like a backend engineer ✅ You debug with confidence ✅ You stand out instantly ⚡ Final Reality Check Most people learn Java syntax… Very few understand how Java actually runs. 👉 Be in the top 1%. 👉 Follow now — I break down real developer concepts daily for the next 30 days.

Java roadmaps often fail for one simple reason: they teach tools, but not order. What usually gets developers stuck is not a lack of effort. It is learning things out of sequence. Jumping into Spring too early, skipping SQL, or treating frameworks and tooling as knowledge creates gaps that only become obvious later, once the work starts looking more like real systems and less like tutorials. A more useful Java roadmap for 2026 starts with the foundation. First comes core Java: syntax, control flow, arrays, classes, objects, exceptions, package structure, classpath, and the basic toolchain. Then the standard library: collections, generics, lambdas, streams, Optional, records, file I/O, StringBuilder, Math, and the Date/Time API. This is the layer that turns Java from something you can write into something you can reason about. After that come the everyday tools that shape real work: Git, GitHub or GitLab, IntelliJ IDEA, debugging, refactoring, Maven, and Gradle. Then comes one of the most important sequencing decisions in the whole roadmap: data persistence. Learn SQL and JDBC before Hibernate or JPA. If you skip the database layer and go straight to ORM, you end up using abstractions you do not really understand. Only then does the enterprise stack start to land properly. Spring Web, Spring Data, Spring Security, and dependency injection make much more sense once the lower layers are already in place. After that, testing and code quality become essential: unit tests, integration tests, mocking, faking, and eventually more advanced approaches such as mutation testing, property-based testing, and BDD. From there, the roadmap moves into deployment and infrastructure with Docker, CI/CD, GitHub Actions, and Jenkins, and ends with concurrency and java.util.concurrent. That order matters more than most people think. That is the real roadmap in one sentence: not learning everything, but learning the right things in the right sequence. If you prefer a video walkthrough, Pasha Finkelshteyn covers the roadmap here: https://hubs.li/Q04clKcF0 Roadmap PDF: https://hubs.li/Q04clFF90

🚀 Core Java Notes – Strengthening the Fundamentals! Revisiting Core Java concepts is one of the best investments you can make as a developer. Strong fundamentals not only improve problem-solving skills but also make advanced technologies much easier to grasp. Here’s a quick breakdown of the key areas I’ve been focusing on: 🔹 OOP Principles Understanding Encapsulation, Inheritance, Polymorphism, and Abstraction helps in writing clean, modular, and reusable code. 🔹 JVM, JDK & JRE Getting clarity on how Java programs run behind the scenes builds a deeper understanding of performance and execution. 🔹 Data Types & Control Statements The building blocks of logic—essential for writing efficient and readable code. 🔹 Exception Handling Learning how to handle errors gracefully ensures robust and crash-resistant applications. 🔹 Collections Framework Mastering data structures like Lists, Sets, and Maps is key to managing data effectively. 🔹 Multithreading & Synchronization Understanding concurrency helps in building high-performance and responsive applications. 🔹 Java 8 Features Streams and Lambda Expressions bring cleaner, more functional-style coding. 💡 Why this matters? Core Java isn’t just theory—it’s the backbone of powerful frameworks like Spring and enterprise-level applications. The stronger your basics, the faster you grow. Consistency in fundamentals creates excellence in coding 💻✨ 👉 If you found this helpful, feel free to like 👍, share 🔄, and follow 🔔 Bhuvnesh Yadav for more such content on programming and development! #Java #CoreJava #Programming #SoftwareDevelopment #LearningJourney

Seriously I am considering stop using Lombok in my new java projects. To be honest, It help quite a bit to avoid Boilerplate of code. Por ejemplo @Slf4j, @RequiredArgsConstructor, @Getter, @Setter, @Value, etc. But Lombok comes with trade-offs that compound over time: - Lombok hooks into javac internals. Every major JDK release risks breakage, and the fix cycle can block your upgrade path. - Security and supply chain risk: Every dependency is a potential vulnerability. Lombok runs as an annotation processor inside your compiler and has deep access to your build. Even if Lombok itself is safe today, it’s one more artifact in your supply chain to monitor, and one more entry point if compromised. If you were around for the Log4j CVE during the 2021 holidays, you know how painful an urgent dependency patch can be. The fewer dependencies you carry, the smaller your blast radius when the next CVE drops. - IDE support gaps: Annotation processing surprises new team members. Code navigation, refactoring tools, and static analysis don’t always see Lombok-generated code. - Debugging blind spots: Stack traces reference generated methods you can’t step into or read in source. - Dependency on a single library: Lombok is maintained by a small team. If the project slows down, your codebase depends on it. For more details you have to read this post autored by Loiane G. https://lnkd.in/e54x8G8V  

🚀 Understanding Inheritance in Java: Building Scalable Object-Oriented Systems Inheritance is a foundational concept in Java that enables developers to create structured, reusable, and maintainable code by establishing relationships between classes. At its core, inheritance allows a subclass (child class) to acquire the properties and behaviors of a superclass (parent class) — promoting code reusability and logical design. 🔹 Why Inheritance Matters in Modern Development • Encourages code reuse, reducing redundancy • Enhances readability and maintainability • Supports scalable architecture design • Models real-world relationships effectively 🔹 Basic Example class Animal { void eat() { System.out.println("Eating..."); } } class Dog extends Animal { void bark() { System.out.println("Barking..."); } } In this example, the Dog class inherits the eat() method from Animal, while also defining its own behavior. 🔹 Types of Inheritance in Java • Single Inheritance • Multilevel Inheritance • Hierarchical Inheritance (Note: Java does not support multiple inheritance with classes to avoid ambiguity, but it can be achieved using interfaces.) 🔹 Key Concepts to Remember • extends keyword is used to inherit a class • super keyword allows access to parent class members • Inheritance represents an "IS-A" relationship (e.g., Dog is an Animal) 💡 Final Thought Mastering inheritance is essential for anyone aiming to build robust backend systems or work with frameworks like Spring. It forms the backbone of clean architecture and object-oriented design. 📌 I’ll be sharing more insights on Encapsulation, Polymorphism, and real-world Java applications soon. #Java #OOP #SoftwareEngineering #BackendDevelopment #CleanCode #Programming #Developers

I’m excited to share the announcement of the next major release of the Tascalate Async/Await library. This library extends Java to support the async/await programming paradigm across Java versions 8 through 25, delivering a seamless, developer-friendly approach. By offering runtime APIs and bytecode enhancement tools, it enables Java developers to use async/await programming style with syntax closely similar to what's found in C# 5+ or modern ECMAScript. This allows to use imperative programming constructs like for/while loops, if/switch statements, structured exception handling etc, while preserving all the benefits of asynchronous programming without blocking threads. The Tascalate Async/Await provides support for asynchronous tasks and asynchronous generators within any kind of Java application. In this new release, it provides robust integration with SpringBoot projects, supporting Standalone, WebServlet/SpringMVC and WebFlux setups. Additionally, it offers two-way integration with Reactor.io stream publishers, with plans to add the similar functionality for SmallRye Mutiny in an upcoming release. The library is entirely free from gluten, lactose, albumin, Generative AI-generated code, formaldehyde, paraphenylenediamine, and any other allergenic components. For more details and detailed documentation, visit the project’s homepage at: https://lnkd.in/d9dEyjDd.

🚨 Exception Handling in Java: A Complete Guide I used to think exception handling in Java was just about 👉 try-catch blocks and printing stack traces. But that understanding broke the moment I started writing real code. I faced: - unexpected crashes - NullPointerExceptions I didn’t understand - programs failing without clear reasons And the worst part? 👉 I didn’t know how to debug properly. --- 📌 What changed my approach Instead of memorizing syntax, I started asking: - What exactly is an exception in Java? - Why does the JVM throw it? - What’s the difference between checked and unchecked exceptions? - When should I handle vs propagate an exception? --- 🧠 My Learning Strategy Here’s what actually worked for me: ✔️ Step 1: Break the concept - Types of exceptions (checked vs unchecked) - Throwable hierarchy - Common runtime exceptions ✔️ Step 2: Write failing code intentionally I created small programs just to: - trigger exceptions - observe behavior - understand error messages ✔️ Step 3: Learn handling vs designing - try-catch-finally blocks - throw vs throws - creating custom exceptions ✔️ Step 4: Connect to real-world development - Why exception handling is critical in backend APIs - How improper handling affects user experience - Importance of meaningful error messages --- 💡 Key Realization Exception handling is not about “avoiding crashes” 👉 It’s about writing predictable and reliable applications --- ✍️ I turned this learning into a complete blog: 👉 Exception Handling in Java: A Complete Guide 🔗 : https://lnkd.in/gBCmHmiz --- 🎯 Why I’m sharing this I’m documenting my journey of: - understanding core Java deeply - applying concepts through practice - and converting learning into structured knowledge If you’re learning Java or preparing for backend roles, this might save you some confusion I had earlier. --- 💬 What was the most confusing exception you faced in Java? #Java #CoreJava #ExceptionHandling #BackendDevelopment #SpringBoot #LearningInPublic #SoftwareDevelopment #CodingJourney

The first time my Java program crashed… I thought I broke everything. Turns out, I was just missing one important concept: 👉 Exception Handling That moment completely changed how I write Java programs today. 💡 My Realization Moment I wrote a simple Java program. Everything looked correct. No syntax errors. But when I ran it… 💥 Program crashed. That’s when I understood: 👉 Writing code is one skill. 👉 Handling failures is another. And that’s where Exception Handling comes in. ☕ What is Exception Handling in Java? In simple words: 👉 Exception Handling is a way to handle unexpected errors without crashing the program. Real-world applications must handle errors gracefully, not just stop working. Without exception handling: ❌ Program crashes ❌ User experience breaks ❌ Data can be lost With exception handling: ✅ Errors are handled ✅ Program continues safely ✅ Users stay happy 🚗 Real-Life Analogy Think of Exception Handling like a seatbelt in a car. You don’t expect an accident… But if something goes wrong, 👉 the seatbelt protects you. In Java: try → Risky operation catch → Handles the problem finally → Always runs (cleanup work) ⚠️ Common Beginner Mistakes I Learned to Avoid 🔹 Ignoring exceptions completely 🔹 Using catch blocks without understanding the error 🔹 Catching generic Exception everywhere 🔹 Forgetting the finally block for cleanup 🎯 My Biggest Takeaways 👉 Errors are not failures — they are signals. 👉 Robust programs don’t avoid errors — they handle them. 👉 Good developers expect problems before they happen. I’m currently strengthening my Java fundamentals, one concept at a time, and Exception Handling has been one of the most eye-opening topics so far. #Java #JavaDeveloper #ExceptionHandling #Programming #BackendDevelopment #CodingJourney #SoftwareDevelopment #LearnJava

💡Functional Interfaces in Java — The Feature That Changed Everything When Java 8 introduced functional interfaces, it quietly transformed the way we write code. At first, it may look like “just another interface rule” — but in reality, it unlocked modern Java programming. 🔹 What is a Functional Interface? A functional interface is simply an interface with exactly one abstract method. @FunctionalInterface interface Calculator { int operate(int a, int b); } That’s it. But this “small restriction” is what makes lambda expressions possible. 🔹 Why Do We Need Functional Interfaces? Before Java 8, passing behavior meant writing verbose code: Runnable r = new Runnable() { @Override public void run() { System.out.println("Running..."); } }; Now, with functional interfaces: Runnable r = () -> System.out.println("Running..."); 👉 Cleaner 👉 More readable 👉 Less boilerplate 🔹 The Real Power: Passing Behavior Functional interfaces allow us to pass logic like data. list.stream() .filter(x -> x % 2 == 0) .map(x -> x * 2) .forEach(System.out::println); Instead of telling Java how to do something, we describe what to do. This is called declarative programming — and it’s a game changer. 🔹 Common Built-in Functional Interfaces Java provides powerful utilities in "java.util.function": - Predicate<T> → condition checker - Function<T, R> → transformation - Consumer<T> → performs action - Supplier<T> → provides value 🔹 Why Only One Abstract Method? Because lambda expressions need a clear target. If multiple abstract methods existed, the compiler wouldn’t know which one the lambda refers to. 👉 One method = One behavior contract 🔹 Real-World Impact Functional interfaces are everywhere: ✔ Stream API ✔ Multithreading ("Runnable", "Callable") ✔ Event handling ✔ Spring Boot (filters, callbacks, transactions) ✔ Strategy pattern 🔹 Key Takeaway Functional interfaces turned Java from: ➡️ Object-oriented only into ➡️ Object-oriented + Functional programming hybrid 🔁 If this helped you understand Java better, consider sharing it with your network. #Java #FunctionalProgramming #Java8 #SoftwareDevelopment #Backend #SpringBoot #Coding

🚀 Java 25 is here — what’s new and why it matters for developers The release of Java 25 continues the rapid evolution of the Java platform, bringing improvements in performance, developer productivity, and modern language capabilities. Here’s a concise overview of what stands out 👇 🔍 Key Highlights 🧠 1. Continued Evolution of Language Features Java keeps refining features introduced in recent versions: Pattern Matching enhancements → more expressive and concise conditionals Record patterns & deconstruction improvements → cleaner data handling Progress toward more powerful and readable code structures 👉 Result: Less boilerplate, more declarative logic ⚡ 2. Performance & JVM Enhancements Ongoing optimizations in the HotSpot JVM Better startup time and runtime efficiency Improvements in Garbage Collectors (ZGC / G1) 👉 Result: Faster applications with better resource utilization 🧵 3. Loom (Virtual Threads) Maturity Virtual Threads are now more stable and production-ready Simplifies concurrent programming dramatically 👉 Result: Write scalable, high-concurrency apps without complex async code 🔒 4. Security & Stability Updates Regular updates to cryptography and secure APIs Deprecation/removal of legacy components 👉 Result: Safer applications by default 🧰 5. Developer Experience Improvements Tooling and diagnostics improvements Better error messages and debugging support Ongoing enhancements to the Java ecosystem 👉 Result: Faster development cycles and easier maintenance 🔄 What Changed Compared to Previous Versions? Compared to older LTS versions like Java 17 or Java 21: More mature modern features (pattern matching, records, virtual threads) Less reliance on verbose OOP patterns Strong push toward simplicity + performance Continuous incremental improvements instead of massive disruptive changes 💡 Why It Matters for Java Developers If you're working with Java today, Java 25 means: ✅ Write cleaner, more expressive code ✅ Handle concurrency in a much simpler way ✅ Build more scalable backends with less complexity ✅ Benefit from constant JVM performance tuning ✅ Stay aligned with modern programming paradigms 🧭 Final Thoughts Java is no longer “slow-moving” — it’s evolving fast and in the right direction. Java 25 reinforces that trend: modern language features + high performance + stability. If you’re still on older versions, this is a good moment to start exploring the newer ecosystem 🔥