Gabriel Glodean’s Post

🚀 Java Series – Day 20 📌 Synchronization in Java (Race Condition) 🔹 What is it? Synchronization is used to control access to shared resources in a multithreaded environment. It ensures that only one thread accesses a resource at a time, preventing inconsistent results. 🔹 Why do we use it? Without synchronization, multiple threads can modify shared data simultaneously, leading to a race condition. For example: In a banking system, if two threads try to withdraw money at the same time, the balance may become incorrect. 🔹 Example: class Counter { int count = 0; // synchronized method synchronized void increment() { count++; } } public class Main { public static void main(String[] args) throws Exception { Counter c = new Counter(); Thread t1 = new Thread(() -> { for(int i = 0; i < 1000; i++) c.increment(); }); Thread t2 = new Thread(() -> { for(int i = 0; i < 1000; i++) c.increment(); }); t1.start(); t2.start(); t1.join(); t2.join(); System.out.println("Count: " + c.count); } } 💡 Key Takeaway: Synchronization prevents race conditions and ensures thread-safe execution. What do you think about this? 👇 #Java #Multithreading #Synchronization #JavaDeveloper #Programming #BackendDevelopment

The Java Exception Hierarchy: Know your tools. 🛠️ In Java, not all errors are created equal. Understanding the difference between Checked, Unchecked, and Errors is the "Aha!" moment for many developers. Checked Exceptions: Your "Expect the unexpected" scenarios (e.g., IOException). The compiler forces you to handle these. Unchecked Exceptions (Runtime): These are usually "Programmer Oopsies" (e.g., NullPointerException). They represent bugs that should be fixed, not just caught. Errors: The "System is on fire" scenario (e.g., OutOfMemoryError). Don't try to catch these; just let the ship sink gracefully. Mastering this hierarchy is the difference between writing "working" code and "production-ready" code. #JavaDevelopment #Coding #TechEducation #JVM #SoftwareArchitecture

The Java Collections Framework is a hierarchical structure of interfaces and classes used to store and manipulate groups of objects efficiently. At the top, we have the Collection interface, which is the root for all collection types like List, Set, and Queue. List → Ordered collection, allows duplicates (ArrayList, LinkedList, Vector, Stack) Set → Unordered collection, no duplicates (HashSet, LinkedHashSet, TreeSet) Queue → Follows FIFO order (PriorityQueue, ArrayDeque, LinkedList)

Understanding Bubble Sort vs Selection Sort (Java) Today, I revised two classic sorting algorithms and noted some key differences while implementing them in Java. 🔹 Bubble Sort 1. Time Complexity: O(n²) (Best case O(n) with early stop) 2. Space Complexity: O(1) 3. Multiple swaps can happen in a single pass 4. Large elements move to the end in each pass 5. Optimized using a swap flag to stop early if the array is already sorted 🔹 Selection Sort 1. Time Complexity: O(n²) (Best, Average, Worst) 2. Space Complexity: O(1) 3. Only one swap per pass 4. Smallest element moves to the front in each pass 5. No early termination, even if the array is already sorted Even if the smallest is already at correct position, swap still executes (with same index).

📖 New Post: Java Memory Model Demystified: Stack vs. Heap Where do your variables live? We explain the Stack, the Heap, and the Garbage Collector in simple terms. #java #jvm #memorymanagement

Remember a time when we all agreed that blocking JDBC couldn't possibly scale? Java 25 just changed the game. Between Virtual Threads and the latest JVM optimizations, the "simple" blocking pattern has been vindicated. We can finally have both i.e. our application scalability and our readable code, too. I just posted another update to my series on Non-Blocking vs. Blocking JDBC. After many years of tracking this, the answer seems to be Java 25. Check it out: https://lnkd.in/daW7aWrM #Java #Programming #Backend #TechTrends

Custom Compact constructor in Record In this post under Java Record, I will explain with example what is custom compact constructor, what is the use and how to add them in Record. In the previous post under Java Record, I showed what is canonical constructor, what is custom canonical constructor and what is the purpose of it. Below are the points for recap1) For a Record, Java compiler adds a canonical constructor internally…...

#Java Why does Java not provide default value to local variables? 👉 Answer Java does not give default values to local variables to avoid using uninitialized (garbage) data and ensure safety. 📌 Example class Test { public static void main(String[] args) { int x; System.out.println(x); // ❌ Compile-time error } } ✔ Error: variable x might not have been initialized 📏 Rules (Simple Points) 🔒 Local variables must be initialized before use ❌ No default value is assigned by Java ⚠ Compiler checks this at compile time 📦 Instance & static variables get default values, but local variables do not 🎯 Summary 👉 Java forces initialization to prevent bugs and ensure clean code

In Java versions below 24 virtual threads can pin their carrier platform threads during synchronized blocks or native calls. This prevents the carrier from executing other tasks leading to thread starvation and sub-optimal resource usage. Interesting article on differences between Java 21 and Java 24 in terms how they handle virtual thread pinning. https://lnkd.in/dPpsDYHH

🚀 Arrays in Java (Quick Guide) An Array is one of the most important data structures in Java. It stores multiple values of the same data type in a fixed-size container. ✅ Key Features of Arrays Stores elements in contiguous memory Size is fixed once declared Supports index-based access Faster retrieval using index (O(1)) 📌 Example int[] arr = {10, 20, 30, 40}; System.out.println(arr[0]); // Output: 10 🔥 Advantages ✔ Fast access using index ✔ Easy to iterate ✔ Memory efficient for fixed data ⚠ Limitations ❌ Size cannot grow dynamically ❌ Insertion/deletion in middle is costly (O(n)) 💡 When to Use Arrays? 👉 When the size is known in advance 👉 When you need fast indexing 👉 For performance-critical applications Arrays are the foundation for many advanced structures like ArrayList, Heap, Stack, and more. hashtag #Java #Arrays #DSA #Programming #InterviewPreparation