In Java “an event that occurs during the execution of a program that disrupts the normal flow of instructions” is called an exception. This is generally an unexpected or unwanted event which can occur either at compile-time or run-time in application code. Java exceptions can be of several types and all exception types are organized in a fundamental hierarchy. Understanding this hierarchy is crucial for implementing robust error handling strategies in production.

Java and Kotlin have been at the forefront for Android development and beyond. Java, a very reliable language with over two decades of dominance, has shaped the foundation of countless software applications and systems. Kotlin, on the other hand, is a newer language designed to improve upon Java, offering modern syntax, enhanced safety, and greater developer productivity. But how do these languages compare in terms of features, performance, use cases, and community support?

Today we’re going to be talking about Strings in Java. If you write Java often, you know that a String is considered a first-class object, even though it is not one of the eight primitive types. What you may not know is how to handle Strings in production applications best. From handling internationalization and localization to optimizing performance for large-scale applications, understanding how to work with Strings can significantly improve code quality and maintainability.

One of the most well-known design patterns, singleton ensures the existence of a single instance of a given class during the life of an application. What makes this pattern important and useful? Moreover, what is a design pattern? How do they work? How and when should I use singleton? These questions, plus use cases and examples are covered in detail in this detailed guide.

You might have noticed that your Java program appears slow when handling several tasks at once. Multithreading can help in this situation! Performing operations in a sequential manner is not only inefficient but also a lost opportunity in the world of multi-core processors and advanced software. With multithreading, Java applications can manage several tasks at once, which improves responsiveness and efficiency.

By 1996, developers had already made Java popular for its friendly APIs and automated Garbage Collection, and they started using it widely in back-end systems. One problem, however, was that most of these systems needed the same set of standard capabilities – such as persistence, transaction integrity, and concurrency control – which the JDK lacked at that time. That, naturally, led to many home-grown, closed implementations.

The Java Map interface is a powerful data structure for handling key-value pairs. Present in the java.util package, it’s ideal for managing data associations where each key maps to a specific value. Common use cases include counting occurrences (e.g., word frequency in text), grouping data (e.g., products by category), or accessing items by specific identifiers (e.g., user IDs).

Strings are important concepts in programming and are data types that allow storage of character sequences. String methods are built-in functions that are called on a string to either get information or manipulate data. In Java, strings are treated as immutable data, therefore their values cannot be changed. To work with strings and perform operations on them, you need to understand string methods in Java and how they work.

Picture this: It's Black Friday, and you're circling a packed mall parking lot. Every space is taken, and cars are lined up waiting for spots. You keep circling, but there’s just no place to park and you run out of gas. When you see a java.lang.OutOfMemoryError it’s just like what you experienced in that overcrowded parking lot. The Java Virtual Machine (JVM) has run out of space to "park" new objects in memory. Now here's the thing about Java: it loves objects. It can't get enough of them.

Java provides the essential tools and libraries to deliver exceptional results, from crafting desktop applications to developing mobile apps and complex enterprise systems. With unparalleled versatility and portability, Java is a top choice among developers and one of the most widely used programming languages globally. However, like any programming language, Java isn’t immune to errors. Specifically, runtime errors are a frequent hurdle that developers must navigate.