Exception Handling in Java

In Java, exception handling is a powerful mechanism that helps developers manage runtime errors, ensuring the smooth execution of programs. Rather than crashing the program, exceptions allow you to identify the error, handle it gracefully, and keep the application running.

What Is an Exception?

An exception is an unwanted or unexpected event that disrupts the normal flow of a program. These can be caused by user errors, logic errors, or system issues. Java categorizes exceptions mainly into two types:

Checked Exceptions – Handled during compile-time (e.g., IOException, SQLException).

Unchecked Exceptions – Occur during runtime (e.g., NullPointerException, ArithmeticException).

Why Handle Exceptions?

Without exception handling, an error can cause your program to terminate unexpectedly. Handling exceptions:

Increases program reliability

Helps in debugging and troubleshooting

Improves user experience by displaying meaningful error messages

Basic Exception Handling Syntax

Java provides five key keywords for handling exceptions:

try

catch

finally

throw

throws

Example:

public class Example {

    public static void main(String[] args) {

        try {

            int result = 10 / 0;

        } catch (ArithmeticException e) {

            System.out.println("Error: Cannot divide by zero");

        } finally {

            System.out.println("This block always executes");

        }

    }

}

The try block contains code that may throw an exception.

The catch block handles the specific exception.

The finally block executes whether or not an exception occurs.

Throw vs Throws

throw is used to explicitly throw an exception.

throws is used in method signatures to declare exceptions.

Example:

public void checkAge(int age) throws IllegalArgumentException {

    if (age < 18) {

        throw new IllegalArgumentException("Age must be 18 or above");

    }

}

Custom Exceptions

You can create your own exception class by extending the Exception class.

class MyException extends Exception {

    MyException(String message) {

        super(message);

    }

}

Conclusion

Exception handling is a critical aspect of Java programming. By properly handling exceptions, you make your code more robust, user-friendly, and easier to maintain. Always remember to handle only those exceptions that you can meaningfully recover from, and avoid using exception handling to control normal program flow.

Learn  Full Stack Java Training

Java Basics: Variables, Data Types, and Operators

Control Flow Statements in Java (if, switch, loops

Understanding Object-Oriented Programming in Java

Inheritance, Polymorphism, Encapsulation, and Abstraction

Visit Our Quality Thought Training Institute 


Comments

Post a Comment

Popular posts from this blog

Understanding the useEffect Hook

 React is primarily used for building user interfaces, where components re-render based on changes in state or props. But real-world applications often need to interact with external systems—fetching data, subscribing to events, updating the DOM, or starting timers. These are known as side effects, and React’s useEffect hook is the tool designed to handle them in functional components. What is useEffect? The useEffect hook lets you perform side effects in your component. It's React’s way of combining several lifecycle methods from class components (like componentDidMount, componentDidUpdate, and componentWillUnmount) into a single, unified API. Syntax : useEffect(() => {   // side effect code   return () => {     // cleanup code (optional)   }; }, [dependencies]); The first argument is a function containing your side effect logic. The optional second argument is a dependency array that controls when the effect runs. jsx Basic Example import React, { u...
Read more

What Is Tosca? A Beginner’s Guide

 In today’s fast-paced digital world, software testing has become more critical than ever. Businesses rely on flawless applications to maintain a competitive edge, and automation is the key to ensuring quality at speed. One powerful tool that has gained significant popularity in the test automation world is Tosca. Whether you're a tester, developer, or just curious about automation, this guide will help you understand what Tosca is and why it's important. What Is Tosca? Tosca is a test automation tool developed by Tricentis, designed to automate end-to-end testing for a wide range of applications. It supports web, mobile, desktop, API, and enterprise applications like SAP and Salesforce. Tosca is widely known for its model-based testing approach, which simplifies the automation process and reduces maintenance efforts. Unlike traditional scripting tools, Tosca doesn’t require deep coding knowledge, making it suitable for both technical and non-technical testers. Key Features of ...
Read more