Building Java Barcode Scanner from Scratch

Java Evolved: 112 modern patterns · Java 8 → Java 25 TIL: You don't need to create an object within try-with block, but can just do `try(var) {}` and var will be closed after. Should probably take a closer look a the other 111 patterns. https://lnkd.in/es6Rhu46

Java 9 – Private Methods in Interface We explored one of the most underrated Java 9 features: ✔ Interfaces can now have private methods ✔ Used for internal code reuse ✔ Accessible only inside the interface ✔ Supports clean default & static method logic Example insight: default → inherited by implementing class static → called using Interface name private → only for internal interface use This improves encapsulation inside interfaces 🔥 Abstract Class in Java (With Simple Example) 📌 What is an Abstract Class? An abstract class is a class that: ✅ Cannot be instantiated (no object creation directly) ✅ Can contain abstract methods (methods without body) ✅ Can contain normal methods (methods with body) ✅ Is used when you want common structure + compulsory implementation 🧠 Why Use Abstract Class? Use it when: Multiple classes share common properties But each class has different implementation logic

Use "Anonymous class " to display " happy Java Class!" Here are the steps to create an anonymous class version in Eclipse: Step 1: Create a New Java Project (if not already created) Open Eclipse If you already have the project from Part 1, you can reuse it Otherwise, go to File → New → Java Project Name it "ButtonCallbackDemo" (or any name you prefer) Click Finish Step 2: Create/Ensure Required Files Make sure you already have: ClickListener.java interface Button.java class If not, create them as shown in the previous guide. Step 3: Create the Main2 Class with Anonymous Class Right-click on the src folder → New → Class Name it Main2 Check the box "public static void main(String[] args)" Click Finish Step 4: Add the Anonymous Class Code Eclipse will generate a basic class. Replace it with: java public class Main2 {    public static void main(String[] args) {        Button button = new Button();          // Anonymous class implementation        button.setClickListener(new ClickListener() {            @Override            public void onClick() {                System.out.println("Happy Java class!");            }        });          button.click();    } }

Java Interfaces Today I learned about Interfaces in Java. An Interface is a collection of abstract methods that defines what a class should do, but not how it should do it. By default, all methods inside an interface are public and abstract. Interfaces help developers write flexible, reusable, and maintainable code. They also support multiple inheritance, which allows a class to implement more than one interface. Understanding interfaces helps in designing better programs and improving code structure in Java. 📚 Always excited to learn new concepts and grow my programming skills! #Java #Interfaces #Programming #LearningJourney#SoftwareDevelopment #JavaDeveloper

🚀 Java Revision Journey – Day 09 Today I revised the concept of Interfaces in Java. Java interfaces define a contract that classes must follow by specifying method signatures without providing implementations. They help achieve abstraction and also support multiple inheritance in Java in a clean and structured way. 📝 Topics revised today: 🔖 Interfaces: An interface defines a set of methods that implementing classes must provide. It helps separate the definition of behavior from its implementation. 📍 Class vs Interface: A class can have both method implementations and variables, while an interface mainly defines method declarations that implementing classes must follow. 1️⃣ Functional Interface: A functional interface contains only one abstract method. It is commonly used with lambda expressions in Java. 2️⃣ Nested Interface: An interface defined inside another class or interface. It helps organize related interfaces logically. 3️⃣ Marker Interface: An empty interface (without methods) used to mark a class. The JVM or frameworks check this marker to provide special behavior. Understanding interfaces is important for designing flexible, loosely coupled, and scalable Java applications. Step by step, continuing to strengthen my Java fundamentals. #Java #JavaLearning #JavaDeveloper #Programming #BackendDevelopment #JavaRevisionJourney #OOP

A weekly Java Coding Series – program 128 StringBuilder.append() method in Java – append () is a method of StringBuilder class. It is used to add or concatenate data to an existing string without creating a new object. It is used when strings need to be concatenated repeatedly and gives better performance. It is faster than StringBuffer. It modifies the same object in memory and helps keep the code cleaner and more readable. #java #softwaredevelopment #softwareengineer #linkedincreators #skilledshraddha Program and output –

🚀 365-Day Java Challenge – Day 302 🚀 ⸻ 🔹 Day 302: Try‑with‑Resources Which of the following statements about the try‑with‑resources statement is correct? try (BufferedReader br = new BufferedReader(new FileReader("test.txt"))) { /* ... */ } Options: A) The resource declared in the parentheses must implement the java.io.Closeable interface only. B) The resource is closed automatically at the end of the try block, even if an exception is thrown. C) Multiple resources can be declared, but they must be of the same type. D) The try‑with‑resources statement cannot be combined with a catch or finally block.

🚀 365-Day Java Challenge – Day 308 🚀 ⸻ 🔹 Day 308: Default Methods in Interfaces Which of the following statements about default methods in Java interfaces is FALSE? Options: A) A default method can provide a concrete implementation that classes inheriting the interface can use without overriding. B) A class can inherit multiple default methods with the same signature from different interfaces without any conflict. C) A default method can be overridden by a concrete class to provide a specific implementation. D) An abstract class that implements an interface is not required to implement the interface’s default methods.

JetBrains offers many new features for Java in its IntelliJ development environment and the Koog agent framework. Additionally, there is a new version of Kotlin.

🚀 StringBuffer vs StringBuilder in Java – When to Use Which? While working with Java Strings, I learned an important concept. In Java, Strings are immutable, which means every time we modify a String, a new object is created in memory. When this happens repeatedly (especially in loops), it can reduce performance. To handle this efficiently, Java provides two mutable classes: 🔹 StringBuffer • Thread-safe (synchronized) • Safe for multi-threaded environments • Slightly slower due to synchronization 🔹 StringBuilder • Not thread-safe • Faster performance • Best for single-threaded applications 💡 Simple rule to remember: Thread safety needed → Use StringBuffer Better performance needed → Use StringBuilder Learning small concepts like these helps write more efficient and optimized Java code. Special thanks to my mentor Anand Kumar Buddarapu for guiding me in understanding these concepts and encouraging continuous learning. 🙏 #Java #Programming #JavaDeveloper #CodingJourney #SoftwareDevelopment