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How to Fix The IllegalStateException in Java

An IllegalStateException is a runtime exception in Java that is thrown to indicate that a method has been invoked at an illegal or inappropriate time. To use an analogy, invoking a method in Java when the system is not in the appropriate state is like trying to start a car while it is in "Drive". Just as the car will not start because it is unsafe, a method call results in an IllegalStateException when the internal conditions necessary for its execution are not met.

What does java.lang.Runtime Exception mean?

Present in every version of Java, the java.lang.RuntimeException is an essential class that allows your application to handle unexpected problems without crashing. Runtime exceptions are exceptions only detected during the execution of your app - things like invalid user input or issues with external resources like files or networks. When an unexpected situation like those occurs, a RuntimeException can be thrown and your app can catch and handle it using a try-catch block.

How to Craft and Sign a Custom JWT in Kong Konnect

The JSON Web Token (JWT) is an open standard that allows information to be transferred securely between different parties. The token is digitally signed by using a private key (HMAC) or a public/private key (RSA) by building a JSON Web Signature (JWS). It guarantees that the JWT hasn’t been modified since its creation.

How to Fix the Array Index Out Of Bounds Exception in Java

The ArrayIndexOutOfBoundsException is a runtime exception in Java that occurs when an array is accessed with an illegal index. The index is either negative or greater than or equal to the size of the array. Let’s put that in simpler terms with an analogy. Imagine you have a row of five boxes lined up in front of you. Each box has a number on it. If you want to put a toy in one of these boxes, you have to say which box number you're putting it in. For example, "Put this toy in box number 2.".

Master Kotlin Enums: A Comprehensive Guide

In Kotlin, an enum (short for enumerator) is a special kind of predefined Kotlin data type used to store and represent a fixed set of named constant values, often simply referred to as constants. Each constant is an object, meaning they can have properties and methods, these are enums and are useful for representing elements that are fixed (for example days of the week) and don’t change.

How to Fix the ClassNotFound Exception in Java

When you run a Java program, the Java Virtual Machine (JVM) needs to load various classes to execute the program. The java.lang.ClassNotFoundException occurs when the JVM tries to load a particular class but doesn’t find it in the classpath. One of the most common reasons for the ClassNotFoundException is missing third-party libraries. Double-checking that all necessary dependencies are included in the classpath and that the classpath is correctly configured can prevent this exception.

How to Resolve Java.lang Exceptions

Java.lang exceptions are some of the most commonly encountered exceptions in Java programming. As one of the foundational packages in the Java Standard Library, you don't even explicitly import java.lang in your code; it’s automatically imported into every Java program. Thanks to java.lang you get essential classes such as String, Math, and System, among others. You also get a variety of base classes for handling exceptions and errors.

How to Handle java.lang.IndexOutOf BoundsException

The java.lang.IndexOutOfBoundsException in Java is thrown when an index used in arrays, lists, or strings is not valid. A valid index must be a number from 0 up to one less than the total number of items. For example, in a list of 3 items, the valid indices are 0, 1, and 2. Here’s a quick example: The error message you’d get would look something like this: Here are some other common ways the IndexOutOfBoundsException might be thrown.